Field Test: 2020 Rocky Mountain Slayer Carbon 90 - The One That Broke

Dec 16, 2019
by Mike Kazimer  


PINKBIKE FIELD TEST

Rocky Mountain Slayer Carbon 90



Words by Mike Kazimer, photography by Trevor Lyden



The Rocky Mountain Slayer has gone through several transformations over the years, but the 2020 model has its sights set squarely on big mountain riding. Not surprisingly, it's longer and slacker than the previous edition, and there's now a version with 29” wheels that has 170mm of front and rear travel, while the 27.5” option has 180mm of travel.

Along with the two different wheelsize options, the Slayer is available with either a carbon front triangle and an aluminum swingarm, or a full aluminum frame. All of the frames have Rocky's Ride-4 adjustment system, a flip chip located at the rear shock mount that allows for, you guessed it, four different geometry settings. Most of the testing took place with our size large bike in position 2, which gives it a 64.1-degree head tube angle, 76.1-degree seat tube angle, and a 471mm reach.

Slayer Carbon 90 Details

• Travel: 170mm rear / 170mm fork
• Carbon front triangle / aluminum swingarm
• Wheel size: 29"
• Head Angle: 63.8° - 64.8° (geometry)
• Seat Tube Angle: 75.8° - 76.8°
• Chainstay Length: 442 / 440mm
• Sizes: M, L (test), XL
• Weight: 33.2 lbs (as tested)
• Price: $7,999 USD
www.bikes.com

Our test bike was the 29”-wheeled Carbon 90, which is spec'd with a 170mm Fox 36 Factory fork, DHX2 coil shock, Shimano XTR drivetrain and brakes, and Race Face ARC 30 rims laced to DT Swiss 350 hubs. All that adds up to a retail price of $7,999 USD.




Yes, there's an elephant in the room, but let's take a moment to briefly go over how the Slayer performed before testing was abruptly cut short.


Climbing

The Slayer was designed with descending in mind, but the seated climbing position is comfortable enough that skipping the shuttle truck and pedaling back up to the top every so often is completely feasible.

It has a steep actual and effective seat tube angle, which means that even when the dropper post is fully extended the seat doesn't end up too far behind the bottom bracket. That centered position, combined with chainstays that never felt too long or too short helps make the Slayer a competent climber, although it doesn't feel as efficient as the Yeti SB165 or the Specialized Enduro. That's where the climb switch on the DHX2 coil shock comes in handy – a turn of the blue lever is all it takes to calm the back end down for those longer logging road grinds.


Rocky Mountain Slayer 2020
The Slayer can be run with a coil or air shock, and there are multiple possible geometry settings thanks to the Ride-4 flip chip at the rear shock mount.
Rocky Mountain Slayer 2020
Rocky's own 'Spirit Guide' helps ensure the chain stays where it belongs.

Descending

For a bike with 170mm of travel and 29” wheels the Slayer was surprisingly nimble; there was an unexpected level of liveliness that allowed it to remain enjoyable on tighter, slower speed sections of trail. It did well on the higher speed straightaways, too, although it's not quite stable and planted enough to earn it the mini-DH buzzword - it feels more like an enduro bike with a little extra travel.

There were a couple of instances on steeper section of trail where the front center felt a little short, despite the fact that the 470mm reach isn't out of the ordinary for a bike like this. It's possible that going with a slightly longer stem could have resolved this, but unfortunately we didn't get the chance to experiment. Moderate hits were handled well (except for one...), with enough ramp up to prevent any harshness at the end of the stroke.


Rocky Mountain Slayer 2020

Rocky Mountain Slayer 2020
Rocky Mountain Slayer 2020


It Broke

The Pinkbike Field Test isn't meant to be a test of long term durability; instead, the intention is to get a solid grasp on a bike's handling and component performance over the course of a few weeks of riding. Unfortunately, we ended up finding the limit of the Slayer's strength during a warm-up lap down Whistler's famous A-Line trail.

Disaster struck on the third to last jump. Test rider Luca Cometti hit the jump the same way he had on multiple bikes before, landing a little deep but with plenty of transition left, only to have the back end of the bike break on impact and toss him to the ground on the side of the trail. A trip to the clinic was in order, and while he was lucky to escape more major injuries, he did break a couple of ribs and sustained enough bruising that his time at the Field Test was over. Not good.


Rocky Mountain Slayer 2020

Rocky Mountain Slayer 2020
This Rocky-branded axle is used across much of their range.
Rocky Mountain Slayer 2020
Our current theory is that the axle broke first, and then the resulting twisting force pulled the back of the chainstay apart.

What Exactly Happened?


We don't know. Our current working theory is that upon landing, the Rocky-branded axle snapped at the driveside threads, causing the wheel to twist and tear the non-driveside chainstay apart. We wondered if maybe an early sample of the alloy rear triangle didn’t get a proper heat treatment, but testing it for hardness showed that it measured within Rocky Mountain’s parameters, so that wasn't the problem. The axle itself was neither overtightened nor loose; we had a certified mechanic doing the tire swaps (for control tires) and re-installing the wheels on the bikes—so we know it wasn't Levy's huge guns that caused this.

To their credit, Rocky Mountain didn't give us the 'pre-production' excuse – the bike we had was a full production model. The Slayer also far exceeded all of Rocky's in-house and third-party testing before production, which made the failure we experienced even more surprising to them.

Rocky's position is that despite this failure, the Slayer is safe to ride. They issued the following statement:

bigquotesRocky Mountain’s team of athletes and engineers are passionate about mountain biking. We pursue an ongoing process of continuous improvement of our bikes. In this spirit, we’ve been studying the bike that Luca was riding and we’re looking for opportunities to make improvements to our manufacturing process, design, and fine-tune our already stringent testing process. This is to ensure the durability of our bikes and the safety of those who ride them.Rocky Mountain Bicycles

So is there simply not enough material around that cool looking blind pivot? Are other bikes from other brands out there time bombs just waiting for an axle failure that would cause them to tear apart like this? All the bike strength tests we know of assume the structural integrity of the axle, so that is certainly possible. We don't have those answers today.

We had high hopes for the Slayer, but because it broke during riding conditions that should have been well within the realm of its capabilities, we can't recommend it—for now. We hope the reasons for the failure become clearer, and Rocky Mountain can address any issues quickly. Once that happens, we'll give the Slayer another try.


Pros

+ More versatile than travel and geometry numbers suggest
+ Good traction in rough or loose terrain
+ Comfortable climbing position

Cons

- It doesn't have high-speed stability of some other bikes in this category
- It broke catastrophically



658 Comments

  • 511 35
 THIS is how you respond to test failure. Rocky showing humility and responsibility for their product, unlike the previous failure in the test which spiraled into what was effectively an accusation that pinkbike pursues failure in their reviews to drive views and clicks.
  • 211 2
 Seriously! It's so refreshing to hear "we don't know but we're going to find out" as opposed to the litany of bullshit and excuses we customarily hear.
  • 85 172
flag TimRidesBikes (Dec 16, 2019 at 7:21) (Below Threshold)
 A Canadian company vs an American company *cough* Yeti *cough*. One wants to make a good product and accepts responsibility for breaks, the other claims a pre-production model was sent for use.
  • 64 6
 Absolutely. Even with the bike breaking, I like the brand even more after reading their honest response and commitment.
  • 221 40
 We commenters on pinkbike are passionate about mountain biking and everything we find on this site. We are constantly looking for opportunities to deepen our dissatisfaction, and enhance the ourtrage coming from our keyboards. We bathe in misery and make sure every bike company gets their dosage of hatred. Unless it is pre Fox Marzocchi off course. We appreciate your rather meaingless, dishonest PR enthusiasm over a load of self centered, accusational apologetics from Finland, and we are looking forward to see an updated version of your Slayer. It better be 26".

Sincerely yours Pinkbike Audience.
  • 8 4
 @TimRidesBikes: keep in mind, one is about +1500$ MSRP frame only........
  • 66 3
 @TimRidesBikes: I thought Pole was a Finnish company. But yeah, the USA totally sucks ????...
  • 48 0
 @TimRidesBikes: I think American companies are so scared of getting sued, they never want to admit publicly that something was their fault. It’s sad really but I don’t blame them. You have to be really cautious what you say publicly. Even if your just trying to be honest it can bite you in the ars.
  • 68 2
 @TimRidesBikes:
That was an axle for a shorter travel cross country prototype and never should have been sent out. Hee hee hee...Pole.
  • 26 7
 It was indeed a good response and differs dramatically from pretty much every other company's response to their (prototype) product failing in the public eye.

However, PB stated "Rocky's position is that despite this failure, the Slayer is safe to ride."

I'd like to hear directly from @RockyMountainBicycles that "the Slayer is safe to ride."
  • 2 2
 Completely agree, although the last iteration of the slayer was vastly better looking so along with this fail, it's not hard to decide where to put my money should I want an RM...
  • 112 3
 I'm not sure I agree that this is a great response. Yes, it's good that they didn't blame PB testing or claim pre production. But they've given no reassurance to the owners of these bikes out in the field that they are safe to ride. Let's face it, we've been bitching about how long this field test has taken to come out for long enough that RM have had time to do a pretty thorough investigation!
  • 9 0
 Another issue is how warranty is being handled and honored by bike manufacturers now that they have a life time warranty. Their response would be more like "sorry we're not going to warranty your bike but we can offer you crash replacement [on a bike that snapped out under you and nearly killed you] because you crashed it". Pretty sure the bike caused the crash.
  • 12 10
 @mountainsofsussex: OP sounds like a fanboy tbh
  • 74 6
 I mean, it's cool they are transparent, but this failure is fucking insane. There is no reason a bike that is marketed to be this tough should ever brake like this. I'm sure it was an issue with this specific frame, but if its not I really don't have much faith in the engineer of this bike.
  • 24 12
 Let's be honest, If that was a random accident and RM would like to assure people how good Slayer is, they should put Thomas Vanderham on it, send him to one of FESTs and film it. As simple as that. Pole doesn't have this luxury so RM should use it.
  • 30 3
 @TimRidesBikes: If you don't think Yeti -- or any company, for that matter -- wants to make a good product... C'mon, man. That's absurd.
  • 35 1
 Rocky Mountain has a lot of experience dealing with broken bikes though. It's not their first rodeo.
  • 9 3
 @bikerbarrett: Oooh encouraging... I'd rather they broke PRE-production, not after they think they've nailed it and sold it to the public.
  • 27 31
flag WAKIdesigns (Dec 16, 2019 at 8:17) (Below Threshold)
 @landscapeben: so what you are basically saying, you prefer to hear the straight forward lie about the prototype over a vague BS about how much they try to make the best bikes out there and they are bummed about the failure? Oh no I am not trying to give you a hard time, in fact since we are all quite irrational, your approach is quite refreshing and thought provoking.

"I want to be bullshitted in a more skillful manner" instead of rather delusional "I want to hear the truth". delusiuonal because in reality nobody wins by learning the truth. In such cases attempt at telling the truth does more harm than good, it gets interpreted and spun off. Nobody wins. nobody.

Yes "when you are bullshitting me, I want you to make me feel good about it" - "it's not about the truth, it's about how your statement makes me feel" - philosophical but very interesting aspect of PR in my opinion.
  • 69 1
 Ordering a 8k Slayer right now, test out this new health insurance.
  • 18 1
 @bikerbarrett: I've seen and visited the RM Broken Chainstay Saloon too many times to think this was just a fluke...
  • 44 0
 @WAKIdesigns: Yeah, I think either way, this is a no-win for Rocky. Their honesty might be refreshing, but it's doesn't inspire me with confidence in the product. It's not going to banish the thought in our minds that as we're riding these at Mach 100, it could catastrophically fail at any given moment. They are going to have a hard time selling these after this, which, if there's an actual design flaw, is for the best. Their bad luck if it was just a fluke. I know we as Pinkbike readers like to revel in the drama and excitement news like this brings, but in actuality, it just kind of sucks. There are no winners here. Rocky's reputation takes a ding, the test pilot has a broken rib, and all the people who went out and bought this bike are now thinking in the backs of their mind, "Oh, shit."
  • 18 20
 I snapped the carbon links on the new 2020 Specializes Enduro. The amazing part was that the bike didn’t fail and a big high speed buck to rocks. The company apologized and said that had to run tests replicate my description of the circumstances. They sent me beefier aluminum links and are sending me a new frame when they get them in stock. To me the big difference between this and the slayer is that mine didn’t crumble(had it I may have sued) and I rolled out through a rocky minefield until the bike completely failed. Now I’m scared to ride this bike the same way. My Ripmo(a bike with a lot less travel and less bottom out resistance) survived the same drop though less speed and I avoided the same rock landing.
So point being new bikes braking and almost getting us killed WTF?
  • 10 0
 @WAKIdesigns: No... I'm saying I want their prototype testing stressing etc to be the point at which they allow the bike to fail and build in the strength where it's needed then release the bike to the public when it's safe. No brainer really. I don't want them to lie to us, I just want them to release a finished product, that's what testing is for! As riders we take plenty of risks, but i'm sure we don't want the bike 8k bike we just bought to be one of them. That's what i'm saying.

Rather have the last iteration anyway, way better looking Beer
  • 34 5
 @TheR: Bikes fail all the time it just so happens this one was captured by PB. Every bike will fail eventually and under the right circumstances regardless... the only concern you should have as a consumer is the rate of failure. So if this is recurring and the manufacturer doesn't respond, then of course its an issue. but this could easily be a one off. I've seen a cracked canfield balance, cracked Demo's, Cracked Ibis HD3, Crack Yeti SB130... you name it, they all fail eventually, just ask your local wrencher!
  • 9 0
 @BoneDog: Yeah, I think you're right. But in the irrational world in which we live, thousands of riders having seen this visual on Pinkbike will have a far bigger impact than hearing through the grapevine about someone's Ibis or Yeti cracking. That's Rocky's bad luck, unfortunately. I don't revel in it -- I fee bad for them.
  • 17 1
 Check it out on Vital MTB those downvoting. 2020 Specialized enduro bike check. Links snapped like twigs! At a 175lbs I’m no bike killer. It’s not good when products supposedly designed for hucking fail.
  • 6 1
 Full heartedly agree. And sometimes things like bikes that are put through conditions as rough as mountain biking just break, and that's an acceptable answer that is was a fluke accident. No bike is indestructible despite what the manufacturer tells you.
  • 2 0
 @Yetimike2019: I'm not a huge fan of carbon links, but it's easy to see with the way the link is setup on the Enduro that one of the two of the links that failed on yours (I saw the photos on Vital) failing could easily lead to the other failing, as well.

The upper/lower rockers being carbon wouldn't worry me too much outside of maintenance (I prefer removal/installation of bearings on alloy to carbon), but those two smaller arms on the side seem like they should be burlier or made of another material, a few hard bottom outs and it seems easy to see how they'd be compromised. They are def. the weakest part of the link.

I've got a few weeks on my build with alloy links and I've done some pretty nasty rides, so far no issues. I wouldn't worry about pushing it.
  • 1 1
 @Yetimike2019: are the linkage parts you broke the same material on the s-works und on the cheaper models?
  • 1 0
 @SickEdit: Not him, but the cheaper models use alloy links where the S-Works is carbon. Based on the photos I saw, the carbon portion of the link is what broke.
  • 25 8
 Anyone ever think that he didn’t tighten axle completely and that’s why it came loose and broke which in turn made it demolish frame too ???


We have all left something loose on our bikes and if anyone says they haven’t they are a liar !!!!
  • 1 0
 @WAKIdesigns: With a 7075 TiC welded rear triangle that is...
  • 11 10
 @Don23: if anything, that would rather be overtightening
  • 13 7
 RM has been making quality products for a long time. This thru axle looks like every other axle in the industry and the bikes I ride so I understand they should look at the fail piece but it is likely a slight over/under tightening that cause the failure.

The point is RM is getting out in front of it and addressing it well. With some unknowns they are best to review and try to determine if any changes are necessary. I trust a brand like RM is making every effort in engineering & quality control.
  • 10 20
flag DH-Angel (Dec 16, 2019 at 10:24) (Below Threshold)
 Rocky Mountain said all of their bikes are safe to ride but can't explain the chain stay breakage. This is NOT taking responsibility for the failure! Does anybody believe Rock's bikes are safe to ride after this major catastrophic failure that should never never happen! And that Rocky can't explain it!
  • 6 1
 @WAKIdesigns: The Age of Outrage, you nailed it.
  • 12 0
 @DH-Angel: You have to keep in mind that there also could have been a manufacturing defect in a single part that they will never be able to replicate and may never happen again. If they can't replicate the failure how could they make changes? If the axel failed it could have just been a faulty part.
  • 6 0
 @rtclark: yep, there is no accountability or any recourse to a bike owner that gets screwed in this way. Here's looking at you Cannondale/Dorel.

I had one where I thankfully caught the crack well before the catastrophic failure that could have seriously hurt me on a Jekyll. They still called it crashed related and refused to honor the lifetime warranty even though the bike had never been crashed and their were no scratches etc.. The only blemishes were the paint chipping off around the cracks in the carbon due poor frame alignment/rotation (imagine taking a snickers bar and twisting it in opposite directions at both ends, the chocolate will start to crack, same thing happens with pain on a carbon frame, the carbon will ischemically crack along the fibers, the paint will crack more perpendicular to the carbon cracks).
  • 10 7
 @friendlyfoe: Well, Rocky exaimed the broken dropout and couldn't find any reasons for the failure. I just think the dropout is not strong enough in design. I mean, let's keep it simple, if it breaks it's just not strong enough. The very end of the dropout didn't look like much material. change the dropouts to the strongest aluminum on the market and make it much more beefy and your done. standards are only a starting point.
  • 12 2
 @MTBrent: Yeah, exactly. I'm not seeing this amazingly transparent PR response. Sure, they're not blaming a pre-production sample, they're just saying "Nah, we think it's fine. Go ahead and ride it."
  • 8 2
 @mountainsofsussex: Totally agree. It is corporate boilerplate language, and makes no specific commitment to find the cause of failure, or communicate and fix it.
  • 21 2
 Who cares about the bike? I feel for Luca Cometti's broken ribs!!!! Not a mention in the comments at first glance.
  • 7 2
 @landscapeben: your misinformed, any respectable manufacturer will test the failure modes of the frame. Rocky has a solid engineering team, they don't cut corners. This is bad luck for sure.
  • 10 7
 @endlessblockades: they should make a Down Country version of it and call it Widow Maker which is a damn metal name...
  • 2 1
 Or my favorite “Oopsies we accidentally sent you prototype model”
  • 33 6
 Let's get super nerdy here and break down the failure. My guess is the axle snapped first, only because I've had it happen to me. Now I'm also going to guess that the axle is fed into the frame on the non drive (left) side which means the axle snapped on the drive side (right) where the threads are. Now on that particular jump, you land on the right side facing downwards. This would force the wheel to want to track towards the right, and because the axle was intact on the left side of the bike, it acted like a lever and twisted the left side dropout with tremendous force thus snapping it. Shitty axle, mystery solved.
  • 7 5
 @TheR: I agree with you totally but if a product is selling for that much then fluke breaks are not allowed, ever.
And I'm an RM fanboy Frown
  • 8 0
 @DH-Angel: Well, what are they supposed to say if they haven't been able to find the underpinning flaw?


Even if the truth is "we don't know" I'd rather hear the truth, wouldn't you?
  • 17 0
 @WAKIdesigns: Carson storch has done drops performing 360’s on the new slayer. I have personally owned a lot of Rocky Mountains and never had an issue like this with them. I don’t want to speculate but it could just be a bit of bad luck.
  • 2 0
 @Don23: possible Don, but I assume rocky has looked closely at the condition of the threads on the axle and the actual fracture surface(s)

Not sure if it's interesting or just an oversight on the article but they mention that the material of the chainstay was hardness tested, but didn't mention anything about the axle material?
  • 7 0
 @WAKIdesigns: both possibilities can snap the axle chief, if I have to bet my personal millions on it...I would say , by the way it snapped, it was a loose axle rather than overtight.
I know you know everything but..there is my modest expert opinion
  • 4 3
 @Don23: If that was the case, then we'd see more failures like this ... so no, it was not operator or mechanic error, it was the fault of the bike mfg.

I know it's hard for folks to accept that the bike broke, but think of it this way: The rider, who could have been any one of us, was sent to the hospital because a brand new bike failed catastrophically.

Show me a similar failure, I don't think I've heard of an axle snapping, though it's hard to say whether the axle failed first or the frame failed first.
  • 9 1
 @Ian713: "if a product is selling for that much then fluke breaks are not allowed, ever." That is not how manufacturing works. There will always be failures the goal is to move them from one in a handful of million to one in a billion. There will always be a statistical failure rate.
  • 6 1
 @Ian713: lol have you never purchased a f*cking car???
  • 3 0
 @SickEdit: shinook is correct. The sworks come with carbon links to save a reported half pound. You should be able to purchase those links next year to upgrade the non Sworks. I have been riding around the aluminum links and I think I’m going to stick with the alloy. Specialized claims that the carbon links are just as strong. As far as I know I’m the only person who has experienced this happening.
  • 1 0
 @Don23: completely possible, although impossible to prove at this point.
  • 3 0
 Is the bike ok?
  • 9 12
 I don’t see this as better at all tbh. At this point, I would definitely go out and buy a Pole, because I know I’m not getting the same one that broke. Yes, they could have been honest and just played fairly and put the heavier part on from the start, but at least we know it’s not gonna be the same bike. In Rocky’s case, if I bought it, I would be riding the same bike (on the same trails) without any indication of why it happened and if the bike is structurally sound. Luckily I’d never buy the 29er version.
  • 8 5
 @samslichter: lol wow, you drank the blue coolaid didnt you?
  • 2 0
 @bikerbarrett: I would say they're off to a rocky start, but they have been around since 1981........But they did handle it professionally.
  • 6 0
 @nurseben: I have had very similar axle failures (sheared at the thread root) on both RM and banshee bikes. I don't think it's that uncommon.
  • 1 0
 @BoneDog: ??? U talking about Yeti?
  • 10 9
 @nurseben: "The rider, who could have been any one of us" Probably not though as I, for at least one, will never find myself sending anything too far on a-line Wink
Its frightening following my 7 and 9yo's down there.. I'll leave jumps to the kids.

Worth noting there is a significant difference between riding your own bike and a one that you don't have a financial obligation towards. Not saying he rode it beyond its limits, but you land sideways on every a-line feature at the speeds Luca is clearly capable of and there's a reasonable chance somethings going pop... just like the kid who snapped that pole in the bikepark I suppose.
I bet if you really tried, you could break every single bike in the entire test lineup.
  • 7 2
 "bikes fail all the time"

@BoneDog: Sure, but brand new bikes?
  • 8 5
 > The Slayer also far exceeded all of Rocky's in-house and third-party testing before production

@DH-Angel: Exactly. If testing can't find or repro the issue, either:

A) testing/QA isn't sufficiently rigorous, or

B. Mfg tolerances are too large.

I agree that dropout looks an urban primal earhole earring that went too large too fast. Get more material there stat!
  • 12 5
 > lol have you never purchased a f*cking car???

@BoneDog: I've worked with 100+ vehicle fleets. Dodge & Ford. Recalls coming in all the time.
Brand new vehicle fails, breaking the ribs of the driver? Not even, man.
That's front page news.

Don't normalize this terrible behavior.
RM should take a page from other companies with integrity & issue a recall.
  • 2 0
 @endlessblockades: Agreed, but I will say, he was digging and riding a few weeks ago, so I think he's healed. Or super tough.
  • 2 0
 @Don23: in this case they had felt the play in the rear end very quickly. No way!
  • 6 1
 @Ian713: yes, i would rather hear the truth. But is the truth "it's safe to ride all rocky's bikes" when they can't explain why a catastrophic failure took place.
  • 7 2
 @taijidave: Im going to go with option B

I think that the hub was machined slightly to big for the axle which caused uneven vibration and force on the threaded bit. This could make it a issue on specific builds from select production runs. Regardless of what I think happened rocky should be able to find out why the failure happened and inform their dealers and customers to prevent further failures.

Safety should be rocky's first priority and for them to say that this is a full production bike but it wont happen to other bikes with out giving any explanation to what happened shows their ignorance of the problem and leaves their customers vulnerable to more injury and failure. At least Pole found the reason for their failure and fixed it even if the way they did it was a PR nightmare.
  • 1 0
 @TheR: well put
  • 8 1
 @Don23: nope, if a rear axle comes loose the vibration under braking is instantly very noticeable. I think it’s the design that’s similar to the Commencal Meta AM that also has a reputation for braking axles, the back ends not stiff enough and the flex strains the axle. That’s my theory anyway.
  • 2 6
flag WAKIdesigns (Dec 16, 2019 at 15:30) (Below Threshold)
 @oskimtb: I claim no win in this duel. You win. Everythings. Big Grin
  • 1 0
 Oh how very virtuous you are.
  • 1 0
 @taijidave: and then do what, exactly?
  • 2 1
 @DH-Angel: that was my thought when looking at it, not near enough material to handle the stresses at that location.
  • 4 0
 @Tmackstab:

I would disagree I'm sorry I'm just older and wiser. Just because you run a machine shop doesn't give you any accountability in the structure of said product.

Love your friend ❤️ Shane
  • 3 0
 @egshane: Thanks little buddy. Your salutations and regards have been noted and I have pulled your secret santa gift out of the trash.

Namaste, Tyler
  • 1 4
 @Don23: being a little loose wouldn’t cause the axle to snap.
  • 1 0
 @bikerbarrett: That stings.. But true.
  • 3 0
 @Don23: agree. A loose axle allows it to strike with acceleration rather than smooth force it’s designed to handle. The difference in force between pushing on a nail with a hammer and striking with the same weight is obviously huge and a 29” wheel acts as a longer lever in that regard.
  • 2 0
 @DrPete: it sure can! The same way (loose-ball) hub races/bearings bcome destroyed if ridden hard while loose. Hammer blow force is much higher
  • 1 0
 @MTBrent: can’t upvote this enough.
  • 3 0
 @Tmackstab: let's get super nerdy and guess... Top of the class m8
  • 1 0
 @taijidave: damn right
  • 3 0
 Are you telling me this is just a 1 off ?Wink way to stay positive my friend !@friendlyfoe:
  • 1 0
 @Devz: I don't know about 1 off but I am betting it was the axle and that it's not a design flaw in the triangle.
  • 1 0
 @Yetimike2019: You really did snap them. That S-Works costs 11,000 euro too. Good job bud!
  • 3 0
 To show real integrity, I’d expect that come back with a clear answer on why it happened, evidence to show a) the likelihood of a repeat is very low b) a notice to recall either the axel component or the rear triangle. Shit happens, decent companies, put it right. Good luck keeping riders safe RM.
  • 1 0
 @StevieJB: my rear axle came all the way out on my patrol riding the flow trail in Santa Cruz. I just didn't tighten it enough. It stopped me in my tracks and the tire rubbed off some of my frame cover inside the seatstay. I screwed it back in and rode off no big deal.
  • 2 0
 @mtb-sf: Yeah, that didn’t happen here.
  • 4 0
 @nurseben:
I’ve broken 15mm fork axles twice at about the same area as here (where the thread ends). In this area there is little support from the frame itself, and there will be both torsional and vertical stress if the right and left part of the frame/fork is loaded unevenly and/or the axle is undertightened.

I only ride 20mm axle forks and Kalle’s overbuilt german frames now
  • 1 0
 @Don23: my old brodie thru axle used to come loose over half a run regularly.
  • 1 0
 @friendlyfoe: You are right of course but if I were to spend that kind of money on a bike, I probably wouldn't choose to look at it that way.
  • 2 0
 @BoneDog: Have you ever purchased a new f*cking car that broke down within the first 100Km?
  • 1 0
 @DH-Angel: fair point, I stand corrected.
  • 1 0
 @Yetimike2019: nope, the biggest difference is your axle never sheared.
  • 2 0
 Just saying but the only reason I clicked and watched the video is because of the title.....people want to see carnage. This will drive clicks.
  • 3 0
 @lccomz: Isn't Rocky Mountain a Canadian Company?
  • 1 0
 @blum585: yes, it sure is! I guess you would have to read the downvoted and now hidden comment that I was replying to for proper context.
  • 11 1
 @Yetimike2019: "had it I may have sued" - sums up American litigious society nicely, and very contrary to the original spirit of mountain biking. This sport could never have developed in the first place had people sued every time they hurt themselves. It sucks your bike broke, but nobody forced you off the drop. Show some responsibility man!
  • 1 0
 Too many burritos Luca! Ease off.
  • 1 1
 @Dan686: Everytime I go south its amazing how many lawyer billboards there are on the side of the interstate let alone when you turn on the TV and see all of the ads. It's a sue or be sued society.
  • 4 0
 @Tmackstab @Dan686 : It's one thing when you have something break and try to sue just because it broke, I doubt you'd get anywhere with that.

It's different when your equipment breaks under normal use and you get injured, then incur medical expenses, loss of work, etc. In those cases, it's somewhat reasonable if the design was insufficient or there was an issue that caused it to fail and you end up incurring costs due to no fault of your own.

Showing responsibility is also part of it, for sure, though. For instance, if he was going too fast and slid off the trail and into a tree, that's on him and his poor decision making. If the bike failed, ejected him, and resulted in serious injury due to no fault of his own, then that is something the manufacturer needs to be responsible for. If you have an enduro bike, there is some expectation that it should be able to handle reasonably sized drops, rock gardens, etc without breaking and hurting the rider.

There aren't as many successful frivolous lawsuits as you would think in the US, there is a pretty long running PR campaign to paint some as frivolous to prevent people from suing when it's otherwise justified and legitimate.
  • 4 0
 @shinook: Is the 'sue culture' so prevalent in the states because of health care cost?? Someone gets hurt through no fault of their own but still get stuck with a 50k bill from a broken arm type situation. Honestly curious.
  • 2 0
 @Tmackstab: Sue culture is just you watching our TV shows. No one I know has ever been sued.

On A Team, nobody died, no lower torsos were severed in half by an explosion. That's not real life either. Big Grin
  • 2 0
 @Tmackstab: I started to comment on that but the answer is that I don't really know, I'd expect it's more complicated, but that it is a part of it. There are probably better people to answer that question, but I know that if something broke in a catastrophic way due to design flaws and I got stuck with a 50k medical bill, I'd pursue legal options.

There are other things to consider, though, depending on how serious it was. If I get put out of work, have to have special equipment, etc.

I also believe insurance companies can sue on your behalf and there isn't a lot you can do about it. So if I hurt myself on the bike because it broke, my insurance provider may sue Specialized on my behalf to recover costs.
  • 3 0
 @shinook: "normal use" used to be a pretty ill-defined concept in this sport not too long ago, and still is in many regards. Had early mountain bikers sued for product failures causing injury, I doubt any mountain bike companies would have survived, and I'm sure there were opportunities to do so. I understand we are now in a fairly mature industry but it's built off of the uncertainty and risks undertaken by people in the early days of the sport. Litigation risk absolutely crushes innovation, as the risk skews the incentive curve substantially. Companies can't try new things if they are constantly worried about the real risk of being sued by consumers. Not saying this is that type of case, but FFS, if you choose to mountain bike, you're already in a privileged minority and you should assume that personal risk in conjunction with that decision. Sometimes shit happens that isn't your fault. It doesn't mean you deserve compensation. That entitlement is "sue culture", and it's a uniquely American attitude. I've met people in Canada who have spinal injuries from failed mtb gear.....didn't sue, and wouldn't have even thought of doing so. It's a cultural difference.
  • 2 3
 @Dan686: " That entitlement is "sue culture", and it's a uniquely American attitude. I've met people in Canada who have spinal injuries from failed mtb gear.....didn't sue, and wouldn't have even thought of doing so. It's a cultural difference."
You are 100% taking a cultural bias based on TV, not your experience with actual Americans actually filing lawsuits. You tried to amplify it by saying "I've met Canadians who didn't sue".

Now please stop the nonsense and perpetuation of a rumor.
My useless counter argument is I know people with spinal injuries who haven't sued. I even know of people I don't know...who haven't sued. Has Paul Basagotia sued anyone? I don't know. And I don't pretend he has or has not. What a toilet this discussion is.
  • 1 0
 @shinook: Everything about mountain biking has been about pushing past what the bike can do. And they'll always fail at some point because they are not made of adamantium because Tony Stark doesn't exist.
  • 1 0
 @blowmyfuse: Ease up cowboy.

Go back and read the comment I originally responded to and go back and read the response I was responding to here. Note the countries of origin of the individuals promoting a notion that compensation is in order when there are negative consequences to personal decisions.

Now go and take a look at my geographical location. I'm 20 miles from the US/Canada border. I have plenty of interactions with "actual Americans". I don't watch TV or read sensational politicized news. My opinions on the cultural differences between our two countries are based off of countless interactions with real people, both Canadian and American.

If you'd actually read the comment train with the intent to understand where others are coming from, you'd see that my original point was that suing people after hurting yourself on a mountain bike is generally counter to the entire culture and genesis of mountain biking, and any other "extreme" sport. These sports originated from a notion of "rejecting the system" and generally being rad/gnarly. I can't think of anything less gnarly than suing a manufacturer for a defective piece of equipment that passed through QC.

None of this is to say that a lawsuit would even be successful, as I totally understand that the threshold of proving failure in a duty of care by the manufacturer is challenging to achieve for most situations where this would be an issue. You say below yourself that "everything about mountain biking has been about pushing past what the bike can do". Exactly. I agree. Suing for a bike failure causing injury is thus everything that mountain biking isn't.
  • 1 0
 @mountainsofsussex: 100% agree. This is not a difficult failure to investigate. With some basic knowledge, a decent engineer can tell whether the axle or pivot failed first.

Neither is good outcome but it sure is easier to send a bunch of new axles to owners!
  • 2 0
 "that pinkbike pursues failure in their reviews to drive views and clicks." >> don't they a bit though? it was all over all of their social medias, with clickbait titles...
  • 1 0
 @matiewz: Its a little much, I mean this is the bike industry we are talking about, a very fragile industry were even a large manufacturer like rocky mountain may only pump out a run of 200 of these frames. A drop in sales can be a major hit. It's not as resilient as the car industry.
  • 1 0
 @BoneDog: The car industry are not resilient, just well connected, they have all been bailed out by governments multiple times, kind of like the financial sector
  • 2 0
 @Don23: BS. You will notice a loose rear axle..and that alone shouldn't break your frame to that degree
  • 1 0
 @blowmyfuse: voted up
  • 1 2
 @matiewz: that would be true if failure was common. It isn’t. I will list you stuff that pinkbike broke over 20 years: 2 Yetis, few Enves, one Reserve, Pole, Slayer. Now open any News site like Guardian and show me percentage of bad news vs good news.

Isn’t it ironic that it is mostly carbon frames and components gettijg broken, considering how strong they are supposed to be?
  • 2 0
 @WAKIdesigns: like the Aluminum Pole that broke and the Aluminum swingarm on this bike?
  • 1 0
 @DrPete: isn't it ironic that you missed "mostly"? Also Slayer's crack was rather mysterious with axle snapping first being the possible culprit. Such thing would not happen with SC, Giant or Trek, but is not surprising from a Horst/ Faux bar setup. When the most durable Enve rim cracks time and time again under one of the lighter riders out there, under conditions he claims to not be close to what he is capable of pushing them to, then there is really no excuse. And please don't get an impression that I am an alu suprecmacist, in fact very few people claim alu to be stronger than carbon, which cannot be said about the opposite side of the fence. Hence the poke. Haven't met a single owner of a carbon bike who claims that carbon isn't stronger/more durable and thus isn't worth the increase in the price that goes anywhere from 2 to 8 times pricier than alu. Companies have their share of BS on both sides, commencal being the biggest black sheep of alu side, making Trail bikes heavier than DH bikes from 2008, and they are still cracking!
  • 1 0
 @WAKIdesigns: face it, us Aluminum bike owners are probably subsidizing the cost of carbon frames anyways. Aluminum bikes should be priced cheaper than they are now. And what ever happend to Scandium/Aluminum bikes?
  • 3 0
 @elshadow: they broke mostly. Some several times.
  • 1 0
 @WAKIdesigns: Not sure what your point is here, but obviously any frame material can/will fail. I have broken bikes make of steel, aluminum, and carbon. The carbon bike would almost certainly not have failed if it had been made of aluminum. I have had the identical bike in both aluminum and carbon. The carbon bike rode somewhat better, but I wouldn't say that the price difference was worth it.
  • 250 9
 This is proof we need a new axle standard.
  • 182 1
 Don't you put that evil on me.
  • 36 0
 Or just good axles.
  • 52 1
 17.5 universal, and 17.34 for SRAM because they say it’s lighter.
  • 19 2
 Yes steel as standard Smile
  • 17 0
 @Tsoxbhk: Would have been interesting to see the axle before this happened. It's always an afterthought, but how the threads were cut is pretty critical...any sharp edges at the transition between threads and axle body are stress risers. Most material failures in shear occur at these points. I'm sure their engineers are on it. It would be even better if they released the reason it failed after finding the root cause.
  • 4 0
 Mega XD. Smallest gear being an 11t but use that extra space to beef up the rear axle.
  • 5 0
 @Tsoxbhk: Agree. Broke axel on my Process 111 when it was only ~3 months old. Resulted in broken seatstay. Took a fair bit of coin to get it fixed.
  • 2 0
 Uberboost-squar'd was designed to specifically prevent this sort of failure.
  • 5 6
 The frame broke first and only then the axle broke from the wheel twisting loose around the axle point of failure, oh and old frying pan aluminium is the problem here...
  • 1 0
 @Upduro: 17.49
  • 19 8
 If anything, we need a new metric chain standard to make all parts of all drivetrains obsolete.
  • 10 1
 @Tsoxbhk: Make Axles Great Again!
  • 2 0
 @Tsoxbhk: Or maybe just good QA and QC. Steel axles could be a good option for heavy riders and folks who ride especially hard.
  • 2 1
 30x163
  • 3 3
 @Upduro: Sram dumb
  • 1 8
flag kroozctrl (Dec 16, 2019 at 13:09) (Below Threshold)
 @krashDH85: I bet you some dumbass tighten the axle too tight. It puts all the stress on the shoulder versus the full axle. Every time a see a shear stress failure on the field, it’s always due to someone over torquing.
  • 1 0
 @Happypanda1337: Could be. Simple elongation measurement of the axle would solve that. There is some pretty good analysis comments below. High res photos of each of the components would also tell the story of what came first, the chicken or the egg.
  • 1 0
 Dude don't like the fucking bear!
  • 1 0
 Poke*
  • 2 0
 Threads not in shear is generally good practice.
  • 1 0
 Upvote for the LOLs. But seriously, we need a new hub standard like we need a new wheel size.

*Next PB news release: Look at this amazing 29.5" 161mm Super-duper-booster-plus-plus wheelset!!!*
  • 1 2
 @pnwpedal: 29,5 won’t cut it, 29+ is more than that. Geometries got long enough to fit 32” wheels to Large and Xlarge XC bikes. We should have 32” gravel and road bikes by now.
  • 1 0
 ah ah comment of the year!!
  • 3 4
 The best bit is that changing rear axle diameter to 15mm would mean, smallest cog on cassette would be 12, maybe even 13t. which would mean the biggest cog would need to be 65. Great opportunity to make it 13speed electronic. I can already hear kids on the playground saying that their dad has the biggest cog in town. Little Billy will come home and say that Harrys dad has the biggest cock in town - how do you know that?!.
  • 3 0
 @WAKIdesigns: I have an e*thirteen cassette in front of me. The opening through the 9-tooth sprocket is over 20 mm.

The XD driver and similar designs that do not pass fully through the cassette do not restrict axle diameter in the way earlier designs did.
  • 1 0
 @R-M-R: 15mm front 20mm rear - I like that! The issue is that Shimano and Sram probably won't work with that. New freehub bodies! Yes! All rear wheels become obsolete.
  • 1 0
 @R-M-R: the hole may be 20mm but you aren’t gonna bolt a cassette directly onto the axle. You’ll need space for the hub to come through so that interface can meet the frame. Realistically you could get away with an 11t or maybe 10t using the sort of design e13 used to get away with a 9t, but if you want a bigger rear axle, you’re gonna have to compromise your cassette range.
  • 1 0
 @kleinblake: Not necessarily. It's possible to have the driver fill the volume inside the cassette under the larger sprockets and terminate long before the constrained space near the small sprockets. Look up Kappius hubs for a design that could accommodate a huge axle and small sprockets.
  • 1 0
 @R-M-R: you need an interface to extend from the hub to the frame, and that will have to go through the cassette and around the axle. It will have to be durable so a wall thickness of a few millimeters will be required.
  • 1 0
 @kleinblake: Yes, but it could be pretty slim, especially if it's steel. Alternatively, the axle could have a shoulder that locates the hub, eliminating the need for an end cap on the drive side.

It may not be advantageous - certainly not necessary - just exploring what's possible.
  • 1 0
 After looking again to the pictures the axle threads on the non drive side, making it impossible for the frame failing like that if the axle broke first as that side would be load free and the drive side overloaded
  • 1 0
 @FCX250: Your reasoning is correct, but your observation is incorrect. The axle enters the frame from the non-drive side and threads into the drive side.

theloamwolf.com//wp-content/uploads/2019/08/Screen-Shot-2019-08-12-at-9.54.11-AM.png
  • 1 0
 @R-M-R: I searched for that to be sure but didn't find it, the pictures in the article are not that clear, thanks.
  • 2 0
 @FCX250: The presence of a nut on the driveside is easily mistaken for the head. Uncommon design.
  • 142 3
 well i guess the 'aluminum where its supposed to be' argument isn't all its cracked up to be
  • 11 2
 I can find no fault in this argument.
  • 2 0
 Either material can be solid or not. Aluminum where its supposed to be...with the manufacturer in mind is how I think of it.
  • 3 0
 breaking news - the 'aluminum where its supposed to be' argument won't stay down for long.
  • 4 1
 Yeah, I feel like that argument has been destroyed.
  • 3 4
 "Cracked up to be" LOOOOOOOLLLLL. Pun game strong.
  • 118 1
 Also, heal up Luca!
  • 9 0
 Right. Poor bloke
  • 108 5
 I've worked at a Rocky dealer for the past 5 years. Yeah, like all our other brands they have their fair share of warranty issues. Shit happens. All the time. To every brand. All the time. I'm honestly surprised it doesn't happen more on Pinkbike tests.


THIS one is however a new one. Never seen a rocky fail like that before. Even on the previous slayer, which also had blind pivots (although it was a carbon rear, haters!).

Personally, a bike breaking in a test like this isn't anywhere close to a dealbreaker for me unless it turns out to be systemic like the Giant Stance from a few years ago (not to pick on Giant in particular, they make great bikes too it's just off the top of my head). After working in shops for this portion of my life, if I could only ride brands that I hadn't heard of a manufacturing defect or two, I'd only be able to ride custom made Moots or something. If it turns out some significant percent of slayers does this, then we'll have a problem. Until then, send it.

Moreover, I don't think it happening shortly in to the test is telling. For people that ride a decent amount or hard enough, most warranty issues present themselves within the first 3 months of solid riding. It sucks because it's a really good way to piss off customers (My BRAND NEW CARBON BIKE BROKE ON THE 2ND RIDE AGGGHHH!!!) but that's the reality. Sure, there's a fair deal that break after but in my experience if it's going to happen it'll happen sooner rather than later for riders that send it. I had my first carbon bike break on the 2nd ride and it was a brand new 2015 model at the time. Likewise my first carbon DH bike broke about 4 weeks in to riding season. Those are examples of my own bikes but when I'm seeing them come back, it's usually pretty quick in to the life of the bike.
  • 11 6
 Couldn't agree more, I'd have no brands left to ride if I bought purely based on what I saw get put up in a stand. Most people just don't have the perspective you get in a shop.

Not to mention, PB seems pretty amnesiac... no one here will be riding at this level www.pinkbike.com/news/carson-storch-slayer-raw.html
  • 17 0
 @HaggeredShins: we literally mention that in the video. Smile
  • 10 0
 @brianpark: I don't always watch videos at work but when I do, it's Friday Fails at max volume

To rephrase when I say PB seems amnesiac, its not about you or the editors Wink
  • 1 0
 "For people that ride a decent amount or hard enough, most warranty issues present themselves within the first 3 months of solid riding"

Excellent point. 50% of all returns of my company's product (in an unrelated industry) happen in the first 3 months. The rest are spread out over the next 5 years. If this is a systemic issue with the design, then it will surely be all over the forums because it will be happening to a lot of new bikes. Most likely scenarios are not a lot of people have bought Slayers yet or its not a common failure.
  • 5 0
 @Sardine: Not just your product. It's valid for just about any products life cycle. Highest number of failures happen either during commissioning while the product is new (DOA, dud's etc.) or at the end of life cycle when the product is old/worn out (but those usually don't show up as warranty returns since who would warranty a 10 year old bike for example). It's also commonly referred to as the bathtub curve:
en.wikipedia.org/wiki/Bathtub_curve
  • 10 16
flag garbagecan4130 (Dec 16, 2019 at 13:37) (Below Threshold)
 I disagree. The bike failed quickly into testing and rocky has offered no details into the problem. Rocky provided no further information on why or how it happened or future changes, checks or solutions to prevent or account for why the error happened. While manufacture errors happen often and is a part of the industry I don't feel any of them should be taken lightly. Someone got hurt as a result and it should be there priority to prevent more people from doing the same. If i had to guess what happened i would say that the hub and axle where not perfectly matched which caused added weight on the threads instead of being evenly distributed across the axle. From there everything went down hill. This would explain why it doesn't happen to all bikes as it could only be a problem on specific builds and maybe even different production runs. Regardless it is rocky's responsibility to find the source of the failure and inform there users of ways to find and audit there bikes for similar issues.
  • 9 1
 @garbagecan4130: I remember in the mid-2000s chopping up (literally, with a hacksaw) a bunch of Trek MT220 frames that had been recalled because Trek didn't want them back and for liability reasons we couldn't have anyone pull them out of the trash intact. Not everything is as straight forward as assessing a systemic tube joint flaw on a kids bike, though--give Rocky some time to produce a non-bullshit judgement.

A recall wouldn't be unreasonable here depending on the cause, but speculating is a crap shoot without getting hands on with the frame and possessing detailed knowledge of the design and manufacturing processes involved (hell, even assembly processes given that this in all likelihood originated with the bearing seat). Honestly I think RM is handling this correctly and will give further direction once a root cause is sussed out.
  • 4 3
 @HaggeredShins: your right that i could be way off and it is impossible to tell but that would be my assumption even if it is only a assumption. Regardless I think rocky needs to make a statement quickly because people could currently be riding these and if they cant give a root cause then they cant ensure others aren't at risk. Pole at least explained the problem and how they fixed it.
  • 83 2
 Sick low-key burn on Pole during the video, "not blaming pre-production".
  • 50 5
 Strippers arent the only ones who get Pole-burned
  • 3 0
 @sosburn: that made my day, thanks!
  • 1 0
 Well deserved, tbh.
  • 11 1
 its kinda dumb that they "can't recommend" this bike but didn't say the same for the Pole
  • 13 10
 @hamncheez: our reasoning is that the Pole wasn't a bike any consumer could buy, while the RMB was full production and buyable by consumers.
  • 9 2
 @brianpark: The Stamina now has an entirely new rear end on both models that eliminates the part that broke. Follow up test!
  • 10 8
 @brianpark: Don't agree with you there Brian, you were testing bikes to recommend to customers. PB didn't know Pole had tried to enhance the test by sneaking in a pre-production enhancement (if that's what really happened). And yet, you made a recommendation for it.

That said it may be fair to conclude PB can't recommend the bike if the tests were incomplete, which seems to be the case.
  • 11 2
 @OnTheShore: we didn't make a recommendation for the Pole.
  • 29 17
 @brianpark: "but because it broke during riding conditions that should have been well within the realm of its capabilities, we can't recommend it"- Slayer review

" it's a shame that one of the most impressive bikes in the Field Test is going to have an asterisk beside its name." Pole review

I don't feel like these two statements are comparable.
  • 12 4
 @hamncheez: The statements are different because the situations are different. One bike broke at the end of testing and broke because of a part that consumers won't receive. The other broke at the start of testing and can be bought in the same configuration off dealer floors today.

We've tried to be as transparent and fair as possible here. If we'd had more time on the Slayer before it failed, as well as a clear answer as to what caused the failure and were satisfied that it wasn't something that would affect consumers, our statement about the Rocky Mountain would likely have been much more similar to the one about the Pole.
  • 1 0
 @brianpark: Did RM ever provide some reasoning as to why the failure occurred? I recently witnessed a friend's one week old 2020 Slayer C70 snap its rear axle (where the axle threads terminate) leading to a warped rear triangle... Sounds like a similar failure, no? We'd love to know more...
  • 75 7
 Im guessing the “alloy over carbon” party will be quiet on this release.
  • 99 1
 Steel. We need steel.
  • 26 0
 i'm saving up for an adamantium frame.
  • 5 2
 @fracasnoxteam: Listen to some Judas Priest \m/ They are the Metal Gods.
  • 48 5
 Why? I hold no allegiance to either material but if an axle snaps at speed, the material around it makes absolutely no difference whatsoever.

The stub axle on your Toyota broke. It caused a suspension failure and the fender ended up getting bashed. The fender would have been bashed whether it was aluminum, steel, or carbon fiber.

The MTB world is so needlessly tribal with its allegiances. Carbon is great. Until it breaks. Aluminum is great. Until it breaks. Steel is great. Until it breaks.
  • 11 0
 @jmhills: Obviously, should have been a carbon axle, must be what he's getting at.
  • 9 0
 @jmhills: But steel doesn't break. The interwebz say so.
  • 6 4
 @jmhills: Honestly i dont care i just like to stir the pot
  • 31 1
 I once had a similar axle failure on a steel axle on a road motorcycle. Luca Cometti has my sincere best wishes and "you lucky bastard" thoughts.

But when I look at the picture of the axle my first thought is also that it failed due to fatigue. Note also that it failed at the "thread run out" location. The first article I referenced has a good description of the causes of this kind of failure.

The good news is that there are ways of detecting impending failures of this sort. This axle likely had had an issue which could have been detected before failure, saving a lot of pain and suffering.

This is a not too technical article describing bolt failure and it might be a good read for everyone who turns wrenches on their bike:
www.boltscience.com/pages/fatigue-failure-of-bolts.pdf

Dye inspection:
en.wikipedia.org/wiki/Dye_penetrant_inspection
  • 3 0
 @Dangerous-Dan: Great points. There is a lot going on here from a manufacturing position, especially the rolled vs cut argument.
  • 4 0
 @jmhills: how did you know i drive a toyota?
  • 1 2
 @jmhills: all materials will break at some point and if u arent breaking something ur probably riding Ur local blacktop bike path

I agree with u jMhills
  • 1 1
 @nyhc00:

NYHC FOR LIFE

Off topic, but f*ck yeah!
  • 4 1
 @fracasnoxteam: Does anyone currently produce steel boost thru axles?
  • 3 0
 @Alexanderskh: shut up Mando!
  • 1 0
 @Dangerous-Dan: Super-interesting information, man. I wish I'd been smart enough to get an engineering degree. Sigh... ????

I've no idea if the axle failed due to fatigue, but after reading that I sure would like to know if it was.
  • 1 1
 I'm Holding out for chromag to make a full suspension enduro weapon
  • 1 0
 @Alexanderskh: This is the way
  • 3 1
 @Dangerous-Dan: To me, it looks like the assumption that the axle failed due to fatigue, leading to a sudden yield of the (pretty slim looking) chainstay pivot housing is correct.
The question is why that bolt fatigued. A bolted joint should normally work by the bolt only taking a load along its length. It povides enough clamp force that the friction between the axle and dropouts cannot be overcome, making that the only load path. The bolt will fail if it's loaded in shear (if the axle and dropout slide, for example). Now I'm not sure there's actually enough load on a rear axle at 9Nm to prevent slippage of that joint vertically (not really sure what vertical load to apply in order to do the calcs). So I would expect that the underside of the dropout cutout should contact the top of the axle, providing the vertical load path. The bolt stops slippage under any other loading directions (which are significantly smaller). Now I reckon a professional rider would notice if the axle were loose (I certainly have when it happened to me), so the only option for fatiguing that bolt is that the load path from axle to dropout is compromised, leading to the bolt taking the load. My suspicion is that the cutout in the dropout is cut too high (relative to the bolt hole), so the axle doesn't contact it, making the bolt take the load. I've never really considered how critical those dropout dimensions are until now. Makes me mildly nervous about running a torque cap fork with a normal axle...
  • 2 0
 @fracasnoxteam: My hardtails never break at the rear pivot point... MORE HARDTAILS!
  • 2 0
 @mountainsofsussex: spot on! I too never really considered the importance of the dropout dimensions and manufacturing accuracy until reading your comment. I wish pb would’ve posted more photos of the dropouts and hub cause I’m curious if they show any signs or wear or misalignment etc. I am tempted to show these pictures to the guys in our inspection lab and metallurgy lab here at work to see what they have to say (I work in automotive engineering and we deal with broken shafts/axles/etc like this all the time).

With all that being said, and I do largely agree with your theory, it still seems possible to me that the pivot went first. Maybe not completely even, but maybe just cracked/deformed or even just flexed enough to give the axle/hub/dropout some misalignment which then lead to the axle failure. The whole pivot system could have a number of flaws, improperly pressed bearings, out of spec bearing seat, or even an over torqued pivot axle.

One issue I see with a lot of these modern axle designs is that they do not utilize any sort of pinch bolt to hold the axle in place. Pinch bolts (such as on a fox 40 for example) are great because minimal torque on the axle itself is required, and the the pinch bolts hold it in place without needing to have a huge tension load in the axle itself. On top of that, you really never need to worry about an axle coming loose on you. I know they just got rid of them for simplicity for the consumer and manufacturing, but they do serve a good purpose.

Either way, I know rocky will have the exact cause of this figured out quickly with today’s high tech inspection equipment and other metallurgical inspection, and I’m excited to see what comes of this.
  • 71 6
 Hey everyone,

First off, we’re really happy to see that Luca is back riding! 

When we heard from Pinkbike about what happened, our engineers and technicians began the process of examining all facets of the incident to identify possible causes. We attempted to replicate the failure through numerous test scenarios and during these tests we were unable to crack the chainstay. That said, we’ve taken this opportunity to implement additional quality control measures in our manufacturing process.

The 2020 Slayer is the strongest Slayer we’ve ever built, and it's designed to be ridden hard. It has a reinforced front triangle, reinforced bearing seats, and shielded bearings including dual bearings on the rear triangle.

We’re 100% confident in the Slayer platform and if anyone has further questions, please feel free to reach out to us at info@bikes.com.
  • 6 5
 What about quality control or redesign of the thru axle? If the end with threads isnt hollow it would be much stronger. Also if it wasnt stealth type of axle then people wouldnt overtighten it with a tool, when they would only use the suplied small lever to tighten it. Maybe that was the case with this accident? I've noticed that its quite easy to tighten it a bit too much with a tool..
  • 12 6
 While it may be proprietary information, I'd be interested in a bit more details of the tests that were unable to replicate the failure. Were these all linear machine tests or 3-D machine tests or actual rider tests or some combination?

As an armchair engineer, I'd suggest over-torquing the axle by 35-40% then loosening it a few times to introduce ham-fisted stretch and fatigue, then finishing with it over-torqued by 40%. Then land a few incomplete tailwhips to the tool-tightened side.

Without even having access to the actual frame that failed, I'll bet this is the exact scenario that caused the failure. If this isn't something you tried in your replication attempts, I'd be concerned that you're going to see more of these on the 2020 frame.

As a fan and customer of your bikes, I want to see you guys fix this rather than shrug your shoulders, restate safety claims, and sell more of the exact same configuration.
  • 4 0
 If possible, any elaboration on what exactly "quality control measures in our manufacturing process" entails? I am sitting here with a Slayer C50 29er on order, gazing over at my Flatline Pro sitting that has had a crack in the drop out for over 7 years and I am not exactly confident.
  • 1 4
 @nickkozak: Slayer C50 is an amazing bike. You can buy another rear axle if you're worried about it, maybe dt swiss or rockshox maxle.. Or then you can just take extra care not to overtighten it ever.. its specced to 10Nm of torque. Aluminum doesnt act like steel that "springs back", they will fatigue if overtightened too many times/by too much.. Well 7075 does actually spring a little, maybe thats why dt swiss axles are made from it.
  • 13 19
flag ebrown123 (Dec 17, 2019 at 8:26) (Below Threshold)
 @RockyMountainBicycles you realize what you've just said publicly?

You've just stated "After six weeks of looking at our broken product, we have no clue why it happened. So that makes it totally ok, because we're 100% confident in our product even though it did fail resulting in personal injury."

That's quite the brand statement.

It's YOUR JOB to test until the crack is duplicated and you know the reason why your product failed, not until you get bored or give up trying.

You can't say you couldn't duplicate an existing failure and expect to be taken seriously in any way. Imagine if Boeing tried this approach with the 737 max?

This statement makes your engineers and technicians look incompetent. APEGBC will have a field day with it.

And if you are conflicted about protecting your customers then just protect yourself. It would go a lot better for you if you figured out the problem and owned it before an independent lab or the internet does it for you.

I don't know Luca's situation with regards to this being a work place accident. But if it was you can bet WorkSafeBC is going to be looking for a better answer from Rocky than "We couldn't find a reason so we stopped looking"

Until you are certain and can back up what the issue was or most likely was, the least you could have done is tell current Slayer owners to park them until an authourized dealer has taken the rear apart and inspected the most likely areas for failure.

You would have come out ahead taking this simple preventive step as soon as possible. You would at least look concerned about customer safety and look like you were owning it. The added benefit to you is if this turned up more frames with issues it would help you solve or prevent the issue and if it didn't turn up any other frames then it could help defend your idea that it was a one off.
  • 61 3
 Has 3 pros and only 2 cons. Just sayin.
  • 16 0
 To be fair, after it broke other cons would feel sort of anticlimactic.
  • 20 1
 Plus, they're all going to be on sale now! 50% off if you waive your right to sue.
  • 3 2
 @mi-bike: Seat tube angle more appropriate on a beach cruiser.
  • 22 0
 Pro: Only bike on the market offering a 2 piece axle.
  • 1 0
 Maybe the other con was because of a wobbly cracked axle.
  • 3 0
 @toast2266: *some disassembly required
  • 56 7
 That’s unfortunate it broke, it seems like such an awesome bike. I will offer an alternative theory on the failure:
1. The bearings were pressed in crooked and/or the bores were undersized.
2. This lead to a small crack forming at one or both bores
3. This crack slowly propagated until it critical size during use
4. The chain stay failed causing the seat stay to move in an undesirable fashion, which put substantial bending stress on the axle, which caused it to fail at the thread root

Evidence to support my theory: the small vertical lines on the intact side of the bearing bore, which are usually a sign of an over-pressed or crooked bearing
  • 25 0
 I feel like I’m reading an NTSB report.

I think it might be time for an MTSB.
  • 5 1
 @ninjatarian: love me some NTSB reports
  • 28 8
 That is a hypothesis, not a theory.
  • 15 0
 It wasn't a problem with the seat stays, it would have been a clean breaks and not have been all stretched/bent backwards. Look at the axle and how it broke just inside of the threads and how clean the break is. Either a flaw in the axle casting at the base of the threads or what is most likely the cause is and OVER TORQUED AXLE
  • 2 0
 Ummm, then why did the axle snap cleanly in two?
  • 5 2
 @pdxjeremy: this makes the most sense to me. not gonna lie i would love to hear Pinkbike's confessional that it was their mechanic that over-torqued the axle Big Grin
  • 32 0
 @imho4ep: Maybe it was an over torqued axle, but that doesn't bode well for Rocky. If a professional mechanic over torques the axle and this is the result, think of what'll happen when the general public gets their hands on it. Over torquing is Jerry's middle name.
  • 3 0
 @imho4ep: casting flaw in the axle or order torqued. Either way I wish they would have gotten another bike to test
  • 6 0
 @pdxjeremy: My pet theory is the opposite- the axle backed out a bit and was not longer axially loaded.
  • 4 0
 @toast2266: sure but it's not like there aren't a tonne of these new Slayers out there already, I haven't heard of anyone else saying "yeah that exact thing happened to mine!!"
  • 9 0
 @toast2266: “torque to yield then back off a quarter turn” isn’t how I’m supposed to do it? All my SRAM manuals say that’s gütentight
  • 1 0
 @toast2266: Great comment
  • 5 0
 @imho4ep: Agreed. Which is why I'm skeptical of the over torqued axle theory. There's lots of Slayers out in the wild that haven't broken, and I can pretty much guarantee that plenty of those bikes have over (and under) torqued axles.

Seems more likely that there was a one-off issue with the test bike. Could've been something like Alvey's theory. Could've just been a fluke.

Which is good for Rocky - a singular issue with the test bike is way better than an axle that requires precise torque otherwise it explodes.
  • 9 0
 There is a chance that it was just a material failure. There could be tiny variations in the aluminum that the axle was made out of and that variation was right at the wrong spot and caused a failure. Reminds me of when SpaceX had a resupply mission fail due to a bad strut that holds helium bottles in the stage 2 booster. They figured out 1 in some huge number of struts could have an issue with the grain alignment of the aluminum that would reduce the strength to 20% of predicted. There are little almost undetectable problems that can happen in manufacturing that can cause total failure.
  • 2 1
 @kittenjuice: so if the axle backed out wouldn't the threads on the axle be more exposed to damage? And also I would think the axle would have bent also, not break or shear off.
And look where the axle is broken, right behind all the threads. That tells me the axle was fully inserted into the threads when it snapped or broke. They said this happened instantly so the axle coming loose just doesn't make sense.
Also I'm sure the guys at pink bike can tell when an axle is loose when they are riding it, The bike does all sorts of weird stuff like shifting poorly, dropping chains, wheel moves around ect.
  • 4 0
 @pdxjeremy: Form the axle fracture picture the axle was bent before breaking as you can see from the protrusion that is not perpendicular to the axle centre line.
  • 1 0
 Can anyone imagine the load difference between drive- and non-drive-side chainstay pivot that would be big enough to literally tear the NDS chainstay pivot apart? The NDS pivot is torn apart almost IN-LINE with the chainstay itself. The difference force, between NDS and DS chainstay pivot would have to be working in line with chainstay. And that means horizontally. PB rider dind't hit a 500mm deep hole with the wheel, he just landed some ordinary jump. The torn chainstay pivot seems to be untouched by PB crew, otherwise they would crack the part totally. But its black colored surface is smooth, so it's untouched by PB crew.

The axle thread section IS obiously bent and it sheared suddenly, there are only big sharp edges and faces, nothing smooth. Also, why is that axle hollow in that end? For what reason?
  • 2 0
 @fluider:
There is no way with out looking at the end of the axle with magnification to even really guess what happened. Typically you would expect to see watermarking and then a brittle fracture.
  • 2 2
 @fluider: Actually you reminded me that anti-squat can have a role in failure of the axle and frame, just seeing in loco everything else is speculation.

The axle is hollow to give it more resistance to flexing.
  • 1 0
 @FCX250: And I'd say that there must be some flexing between left and right droupouts and axle, especially in FSR rear ends. The axle may have been overtorqued which prevented it from needed flexing and slipping within the dropout holes.
  • 3 0
 @FCX250: Also, how did they manage to unscrew the axle's thread section from the dropout? It must remained threaded in the dropout after the accident.
  • 2 0
 @FCX250: At this picture: ep1.pinkbike.org/p6pb17996239/p6pb17996239.jpg, it seen that axle nut is still "mounted" on the frame. Probably because the sheared off thread section of the axle is still stuck in there. They were able to unscrew the axle nut, and axle's thread section simply went out.
  • 1 0
 @fluider: If the frame thread is not damaged it isn't difficult to remove the threaded stump that remains as it has any kind of preload to lock it in, if the axle threads in easily that is.

And the axle rupture was caused by the frame failure not the other way around, if the axle went first that side of the frame would be load free and the drive side would be overloaded.
  • 48 1
 I'm sure the answer to why it broke will come by the comment of one the many aerospace engineers that like to read bike reviews here at PinkBike.
  • 14 0
 Lots of aerospace engineers ride bikes...
  • 3 0
 Ahhahahahahahhah
  • 19 1
 Hey, we can't all be dentists.
  • 3 0
 @krashDH85: I like bikes but I guess I have another year before I can truly call myself an aero-e
  • 3 0
 @Ders316: Biking Aero-trainingineer
  • 5 3
 I think the hub was slightly to big for the axle and this is a issue of poor tolerances. It would explain why it happens infrequently and maybe only on select builds. Maybe also why it wasnt stable at speeds and why it broke at the thread. Regardless of what i think it's rocky's responsibility to find out why it happened an inform their customers to prevent it happening again. Say what you want about pole but they at least they provided a explanation and solution.
  • 5 5
 @Vertik you sound like a Volvo engineer... yikes I just insulted half of my friends! Big Grin
  • 3 0
 As an aerospace engineer....
  • 3 0
 @vertik what’s wrong with that? it’s what we do for a living. It broke because it was poorly designed or poorly manufactured. Hard to tell just from the pictures but pretty sure it was one of those.
  • 2 0
 @WAKIdesigns: Ey! Watch it! Razz
  • 35 0
 Nice of you to make this the first Enduro test so people will finally stop asking which one broke.
  • 35 3
 That broken bolt looks like a spiral failure to me....possibly over torqued at some point in its life?

Had a crank bolt snap in exactly the same way, at the base of the threads just like that one...
  • 4 1
 Is the average person going to measure bolt stretch though?
  • 2 0
 I was thinking the same. I hope your comment gets bumped to the top for visibility.
  • 9 0
 @jmhills: no, but they should be following the recommendations stamped on the axle though.... I mean if we start holding companies accountable for poor maintenance practices then every company better start stressing out.Its obviously not good this happened, but personally it seems like a real bad luck scenario, more than a design flaw.

hey @RockyMountainBicycles ...If I am right, you can send me a slayer. Wink I still want one.....
  • 7 3
 The pivot would maybe fail if the axle failed. The axle would very likely fail if the pivot failed.

I’m not convinced it was the axle and that pivot design looks sub optimal IMO.
  • 1 1
 @jmhills: no, it's called a torque spec
  • 5 2
 @jclnv: I would say at high speed like they were testing, either is about as likely as the other if either part were to fail. bikes work as a system and rarely is one connection/pivot strong enough to take the entire forces of . My only argument for the axle breaking first, is that the mechanics of the pivot snapping and then breaking the axle would be a shear or bending failure and the bolt would not have twisted and broke, it would have much more likely bent or sheared.

Alternatively, if the bolt had a twisting failure at the base of the threads (like it appears to have) it would have broke, causing the wheel and axle basically to be a lever arm on the chain stay, and the pivot is just the logical point that that would shear/hinge...

I mean ill leave it to the guys at RM to determine what the failure was...but just doing some armchair engineering...from my desk at an engineering firm. not implying that makes me more right, just have spent some time analyzing structural failures and that would be my input Smile
  • 22 1
 @acdownhill: Riders frequently remove the real wheel for transport or for trail-side maintenance - it's not really reasonable to carry a torque wrench in a backpack / bum bag for each ride. I think they should be made strong enough to allow for some over-torquing.
  • 5 1
 Completely agree with you. I really think it was that axle.. prob some shitty aluminum and no one tests them.
  • 3 1
 @korev: okay? I am not debating if its a pain in the ass to know the exact torque you have put on a bot. but a over torque failure can literally happen to ANY bike that has a thru axle... or an axle at all for that matter.

Its not difficult to use a torque wrench to get a rough feel for what difference there is between 2Nm and 8Nm...and when in doubt, make sure things are tight, but be cautious anytime your putting a lot of force into something. slightly less torque is actually better than too much...

I dont know, is it a carbon bars fault for cracking when you over torque your brake levers?
  • 3 0
 @acdownhill: Good points and you’re far more knowledgeable on the subject than me.

I’d like to see the inside of the chainstay. Depending on what failed first the tire scuffing would likely be the most severe on that side before the velocity was reduced.

Also the more common pivot design where the chainstay clamps the dropout from both sides seems to make far more sense to me.
  • 6 0
 @korev: Even if one carried a wrench, your average Joey's torque wrench is usually +/-10 to 20% or more...8 NM you'd have to hit +/-1...Good luck with that by feel...also did they use grease? If so your K factor has changed which means your torque at the wrench needs to be adjusted. Now to throw another thing on top, when was the last time the torque wrench was calibrated? There are so many factors that come into play that's for sure
  • 2 1
 I've had a Maxle break at the same spot while tightening it, with light torque applied by my calibrated torque wrench wrist. Alum axles these days are pretty darn light...
  • 2 1
 @korev: This is the benefit of quick release over axles that require the use if a wrench. QR is tightened by hand and cannot over stress the axle thread.
  • 1 0
 @jclnv: I've seen a swing break on a Kona Operator and the axle didnt break. Its not the exact same thing as breaking a pivot but its close enough to make me disagree with you
  • 1 0
 @ridelife6: Yeah in hindsight I agree that it was probably the axle.
  • 1 1
 @acdownhill: Most people setup their brakes and never touch them on the trail; the back wheel is probably the thing on the bike that you remove most often away from home.
  • 1 0
 @korev: I don't really understand the point your trying to make. Thru axles seem to work for a vast majority of riders on higher end bikes with no problems. If you have some ideological problem against thru axles, take it up with the manufacturers and not some random person on the internet.

again...literally EVERY axle, and even furthermore bolt can snap due to over torquing. crank bolts, brakes, disk bolts...any of them can break. make them out of aluminum and that goes up 10x probably, as ham fisted home mechanics rarely bust out their 60 dollar torque wrench to work on a 6000 dollar bike.

long story short, when in doubt NEVER torque bolts. you would be much better off getting a bolt tight, but untorqued than an over torqued bolt past its yield point.
  • 2 0
 @acdownhill: It could have easily been the quality of aluminum that the axle was made out of. Tolerances off etc on that batch. It may have been torqued perfectly, with a shitty run it would still be sub par. Would be interesting if Rocky Mountain tested that batch to see if they where manufactured incorrectly. I mean how many brands double check the axles that they mass produce. I bet none do..... plus how many times has that axle been used. This was most likely a test bike provided and that axle may have been used a lot more than the standard person. Still horrible and I hope Rocky figures out what caused it. I have friends with Rocky bikes and I have never seen this happen.
  • 1 0
 @Meettaco: exactly my thoughts as well! I mean all manufacturing has a burn/failure rate and its not unthinkable that a axle that was made improperly, or with materials not of proper grade, or just any material failure could cause this, and it was just a ticking time bomb. I don't doubt that PB had their mechnic doing all the work properly, but if the axle was compromised from the start, it actually could have been the act of torquing to its proper rating that caused it to fail... really hope this is just a one off issue... as this bike was the top of my next bike list.
  • 2 0
 @acdownhill: Agree! Come on PB do some testing on sub par Chinese parts so we all don't buy a bunch of bullshit.
  • 31 2
 Last bike in the test I thought would break.

Luca Cometti: 1

Rocky Mountain: 0
  • 26 0
 Oh snap!
  • 7 0
 cracking joke
  • 24 0
 Nooo im so irrationally disappointed that its the Rocky!
  • 3 0
 A lot of people lost their pool in that one.
  • 22 1
 the slayer got slayed, daamn!
  • 25 12
 Giant Reign in blood!
  • 12 0
 seasons in the clinic
  • 12 0
 Engineering has limits but Evil has no boundaries.
  • 2 0
 Damn, that Slayer went 'South of Heaven'
  • 18 0
 Sketchy af! I’ve got one of these bikes! It’s my favourite bike I’ve ever ridden by far! But now it’s gonna be hard to ride with confidence. Hope they figure it out and send out a better axle or something like that.
  • 3 0
 Robert Axle Project mate. No worries, just replace it.
robertaxleproject.com
  • 18 2
 I've experienced and investigated these kinds of metal failures below. If pinkbike had shared clear focused close ups of the broken frame and axle it would be pretty easy to see which broke first. On a metal failure you can often seen the whether it was a catastrophic, one cycle failure, or a crack propagation, multiple cycle failure by looking at the metal faces at the break. If the broken faces are sharp and crisp it is likely catastrophic. If part of the faces are smoother and then transition to sharp and crisp it is more likely that a crack started at the smooth end, those sharp surfaces rubbed against each other over more cycles, becoming smooth, while the piece continued to weaken as the crack grew. Then the rest of the break occurs suddenly in the weakened part and results in sharp faces for that last region of the crack. So if the frame is showing part smooth, then sharp faces at the break, it likely cracked first, rubbed while the crack grew and then failed once the crack was big enough to cause the part to weaken to sudden failure, taking the axle with it. If the frame is showing all sharp faces at the break, then likely the axle failed first and the frame failed catastrophically next.
  • 13 2
 Addendum to my own post:

Looking at the failed chainstay pivot closer, I'm leaning towards crack propagation starting there, and more specifically at the stress riser caused by that inside machined ridge that the bearings seat on as it has a sharp transition. You can see the crack starting there and angling outward on the chainstay.

Because the pivot is completely visually obscured by the seatstay pivot once the bike is assembled it would be hard to see the crack starting in the chainstay. The crack may have also started on the inside of bearing seat at the ridge and worked towards the outside of the chainstay, making it harder still to diagnose.

Also if the chainstay had failed catastrophically in one shot, it's hard not to believe that the chainstay pivot bolt there wouldn't have been a weaker link and sheared before or with the chainstay itself.

I wouldn't be surprised to see Rocky address this with a redesigned chainstay without that machined seat in the centre of the pivot and a different bearing and bolt configuration.
  • 6 0
 @ebrown123: I agree with your assessment of which part broke first and I provided my reasoning in a separate comment. Any number of things could have caused the chainstay to fail from cyclic fatigue, I personally doubt it was catastrophic, but for the axle to break first just doesn't make sense.
  • 13 0
 One further Addendum:

I went through the various Rocky service manuals I have to see why this hasn't happened before. The 2020 Slayer appears to be the first model to ever have two bearings separated by a machined rib in the chainstay pivot location. Even the Maiden and the powerplay models only use a single bearing in that location.

On paper, I can see why two bearings would seem stiffer and stronger than one. But on paper, the stress risers from that machined ridge and pressed bearings may not have shown up. Even in a frame fatigue testing rig, if there wasn't a lateral load being cycled it might not appear either. Cycling frames up and down isn't the same as real world cycling of frames side to side.
  • 1 0
 @ebrown123:
Step 1: Mount a bazillion strain rosettes in strategic locations
Step 2: Send bike down A-line underneath Forbes, with incentive to land sideways off every jump
Step 3: Process data, develop lab test plan to achieve loading conditions observed in real world test environment (inclusive of all torsional/shear loads you see in these scenarios) plus safety factor of 1.69.
Step 4: Profit!!! (Due to less failed frames?)
  • 1 0
 @ebrown123: I'm holding out for mixed multiple failures. Not disappointed though, as I was already ignoring that swingarm layout, with its long elements and non-overlapping points of support.
  • 11 6
 @mdhorner: The truth could be uglier.

Rocky may not have even tested the new double bearing rear pivot with that new bearing seat rib.

They previously stated that the Wade Simmons Pipedream project was the test mule for the this Slayer and they made the Pipedream with the rear end and single bearing chainstay pivots from the 2018 Altitude.

Someone at Rocky may have decided that since they were taking an already proven and tested rear end and just making it beefier by adding a second bearing that it didn't require any testing even though it was a new design.

It might not be the rib that I've pointed out.

It might be something more subtle like the new position of the axle closer to and higher above the pivot than previous models puts the chainstay in more tension at the beginning of the stroke than before or worse, cycles the chainstay between tension and compression, where it didn't before.

Might have been an oversight, might have been cost related, might have been in a rush to market. Only Rocky can say.

If a lawyer for Luca, Pinkbike, or worse, another injured rider comes calling, I hope Rocky has all of its development and testing well documented.

The frame failed over six weeks ago. That's a lot of time for Rocky to figure out what happened, yet based on their statement for this article they don't seem to know yet which I find more troubling than the failure itself.

Or they may already be in PR damage and liability control mode.

The giveaway will be any design changes they make in that pivot going forward.
  • 4 1
 @ebrown123: Curious on why your not considering the bolt being over torqued at some point in its life as an option? I have looked at the photos with two experienced structural engineers in my office and both seems to think that it appears to be an over torqued bolt...we see a lot of these in the pre-engineered building world. and this looks exactly like many of the bolts we have seen that have failed when they are torquing them. Granted we are talking WAY higher torques in that world.

Once there was a crack within the bolt from it being overloaded (torque wise) then all it would have taken would have been a slightly botched sideways landing to put some lateral forces into it and it would have split. once the bolt snapped there would be no tension to hold the rear end together and the wheel and axle would have just been a lever arm on the entire non drive side chain stay, and the likely place it would break is where there is the least metal (the thin spot at the bearing housing. as far as I have understood (with my measly technician brain) Aluminum is not a terribly good material when it comes to tension... Personally I think this might be another example of why aluminum is a terrible material in anything with high torque requirements.

Not arguing with your points or anything, super informative and interesting! just curious on what makes you eliminate that as a plausible option Smile
  • 3 1
 @acdownhill: It's totally ok to argue points. That's what the comments are for. And it's a group effort so technicians contribute as much as engineers. And hey, I might just be a dentist who plays engineer on the internet...

I can also be wrong. It may have been an over-torqued axle but I think it is much more likely that it is a design or manufacturing flaw in the new chainstay. Only Rocky can say for sure. And I've already pointed out that if they don't actually say anything after looking at if for over six weeks, any design changes will speak for them.

At first, I didn't have an opinion either way, whether it was the axle or the frame. Like everyone here I was looking at the pictures and trying to figure it out. That's when I described the method for checking the faces of the failed parts for smooth and sharp faces as it might have suggested or ruled out which it was and wishing the pictures were higher resolution.

I would agree that the axle most likely failed in tension. The problem is I couldn't tell from the photo but as many have pointed out, the way a thru-axle sits in a frame it makes shear failure very unlikely. Then the question is, even if we all agree the axle failed in tension, did that tension come from over torquing or from the frame spreading as the chainstay failed first?

In my second post I started to lean towards the frame going first from the shape of the failure and that is when I noticed that the crack the chainstay failed along runs up to the that new bearing rib. I also didn't see the chainstay failure as catastrophic, as from the side photo the metal looks bent and worked as opposed to shattered into a few bits. I think this supports a crack that worked itself bigger over some cycles.

I also thought that if the axle was cracking first, say from an over-torque, there would be signs. As the crack was working through the axle from the threads weakening it, the riders would feel rear wheel play as if the axle or hub was just loose and none reported that feeling in the bike before it let go. Another point is that the mechanics were pulling the axle in and out often to change the tires. If the threads were starting to go, the threads would start to deform and the mechanic might either see this or feel it as the axle would be harder to start to engage at the threads when they replaced the axle each time. Last, if the threads had started to crack and fail, the mechanic wouldn't be able to get the required torque on the axle with a torque wrench anymore without the axle breaking then. I feel all of this supports a sudden axle failure over it failing from a crack from cycling.

So this brought me back to thinking the frame went first. Then the next question is why? Rocky has made thousands of bikes with chainstay pivots and thousands of other bikes have been down A-Line. What was different? Was this double bearing and rib design new or the same as in other Rockys? I didn't know so that's when I flipped through the service manuals to see if this was a new design or already used in other Rocky models. It appears to be a new design.

When trying to determine cause of failure, a new element, like the chainstay, is usually more likely than an older proven element, like a thru-axle.

In terms of quality control being a factor, it is much easier to maintain and test strength on something simple like an axle compared to a chainstay. It is common practice and inexpensive to test a handful of bolts to failure from each batch to make sure they meet spec compared to testing a handful of chainstays from each batch in the same way. Likewise, I imagine axle manufacturers have tested failure from over-torquing in the process of specifying the proper torque to use. It would pretty easy to build a jig with a wheel in it, over torque an thru-axle to different levels and drop weights on the edge of the wheel to see how much over torque it takes to compromise the thru axle when the wheel is side loaded. Even the staff at pinkbike could manage this one for an article so I suspect manufacturers already have.

If it was the chainstay that went first, it might be the new design of the bearing seat with the rib causing unanticipated stresses or it might be the quality control of manufacturing this new design. The design may be fine but it could be a bad batch of chainstays that were being made differently for the first time.

And to be fair, it could be something else entirely. Like I said I'm not necessarily right at all.

I've just tried to put my best idea forward based on the info and experience I have. If I was Rocky I'd be working very hard to try and duplicate the failure and see what I could rule out and what I needed to focus on.
  • 2 0
 @ebrown123: thanks a ton for the in depth response! Well if your a dentist, then you have a stellar understanding of mechanical engineering. Wink as for the technician comment, was mostly just being light hearted, I am sure you know enough engineers to know some of them have a type A personality haha.

for sure can follow your path of thought on that. The fact that the rear end appeared to have a "slower" failure is an interesting point, and I am going to discuss that with the engineers in my office. a few of us have taken some interest in this as a bit of a fun distraction from our normal work. I think the fact that they had a mechanic on hand is one of the more interesting points on this for sure, as personally I would have thought either problem would have surfaced in a mechanical check prior to riding. you would think that a crack in the rear would have developed a bit slow and would have also developed a bit of play or roughness before complete failure. but I also agree you would think that a bolt failure would be noticeable too. That is why I find myself keep coming back to the bolt, as it is the most likely human error problem. is there any chance at all he accidentally over torqued the axle? or even furthermore...was this just bad luck and a manufacturing fault existed in this bolt and did it just twist even under normal torque values?

In my head this wasn't even a problem with the threads, but a bolt that was both over torqued AND also threaded in completely to the base fo the threads, thus putting all the force on the section of the axle that tapers from 12mm thick to whatever thickness it is at the threads. Another guy *(Dangerous Dan) above posted an interesting article on how running the end of the threads into a bolt (or in this case the frame) and how that causes fatigue cracking within the bolt, until the axial torsion just twists the bolt apart. the sharp edges of that bolt in the images look like a spiral failure, as it almost looks like a ramp from the side ( not a clear shear failure)

Otherwise I fully agree with your assessment. they re using a lot of technology that already exists in their other bikes, so a logical first step would eb to analyse anything that is different. but with that said, I guess changing one part in the system could cause failure, even in already existing parts. really at the end of the day it is only RM that will know the true answer, hopefully its just bad luck...I wanted a slayer. but this is a nice reminder that the first iteration of any bike, can come with its flaws.

Interesting none the less and appreciate the response. look forward to getting the "truth"
  • 1 0
 @ebrown123: Maybe the two bearing surfaces are hard to machine concentric enough creating opposing stress across the rib. I am not familiar enough to know if anyone else has done this design.
  • 16 0
 Me not engineer but "simply not enough material around that cool looking blind pivot!" is what me think.
  • 15 2
 The broken axle theory doesn’t make sense to me. The hub’s endcaps should be transferring all direct vertical shear loads into the dropouts, the axle really only holds the back end together in compression so the rear hub and dropouts are linked together. It seems to me that the end of the chainstay had some sort of failure which eventually allowed the bearings to tearout of the stay. This would then transfer all of the vertical wheel loads into the unsupported seat stay and the now misaligned axle. The hub effectively pivoted about the drive side dropout and tore the axle. If the axle had somehow failed first, the non-drive side seat stay would have bent in a counter clockwise direction, if looking at the stay from the back of the bike towards the front, but it looks like it bent in a clockwise direction which would suggest the chainstay failed first.

My 2 cents…
  • 1 0
 Given the forces involved in landing that drop, its not hard to imagine the dropouts spreading apart enough to let the hub end cap slip out of the seat. Also, why would the NDS seat stay necessarily bend in the CCW direction? He probably wasn't pedalling up the face of the jump, so there wouldn't have been much tension on the chain.
  • 1 0
 Yes. And the long, diagonal break of the non-drive chainstay end (bearing seat) suggests that oxides/contaminants during production (casting for pre-production?) caused the non-drive side to fail first. The axle should bend, not break, and if the axle did break first, there would be a big mark and deformation at 12-o'clock on the drive-side dropout from the axle escaping the counterbored seat..
  • 2 0
 @Skooks: The dropouts on most bikes are what, 3-5mm deep, something like that? The axle would have had to stretch considerably for the hub to have escaped the drop outs and that would require an insanely bad, sideways landing, which the article doesn't suggest happened. All sorts of weird stuff happens during shock loading so anything is possible, but I honestly doubt the hub moved that much.
  • 1 0
 @rktprov: This could easily happen if the axle failed.
  • 19 2
 still gonna send it.
  • 14 0
 Are you guys silly?
  • 2 4
 @Imtoooldforthisshiz: f*cking amazing this has made its way to Australia! My brother sponsors larry enticer through Gamma powersports!! guys a Gem. his house is nuts, he had a mini bike fest with over 100 people hitting jumps around the house, googgle it
  • 16 1
 Cons:
- It broke catastrophically...
  • 53 0
 to be fair: not-breaking is something i like a lot about bikes.
  • 15 0
 “Infamous...Rocky Mountain branded rear axle of deeeeeaaattthhhhh!!!!’
  • 9 0
 Slow death, immense decay
  • 7 0
 Surgery, with no anesthesia, feel the *axle* pierce you intensely...
  • 6 0
 @fruitsd79: monarch to the kingdom of the crash!
  • 3 0
 A-Line, the meaning of pain
  • 10 0
 I broke the Axle on my Carbon 2019 Kona Process 153 with aluminum rear end while in Squamish.. not exactly sure when, or how.. but I probably rode on it for quite some time, the frame didn't break? I only realized it was broken because I kept having to tighten the axle, I pulled it out to put some loctite on it and then found it broken..
  • 2 0
 Over the past couple years I have witnessed 3 different rear through axles break. 2 at Trans Sierra Norte and 1 MTB trip with a small group. 2 of these were RS Maxles. Makes me nervous for sure.
  • 10 0
 Breaking a 12mm hollow aluminum thru axle at the threads is not that uncommon. It probably cracked or broke earlier in the run and caused the chainstay to fail on the big compression. Unlikely that the whole system was intact and failed on one hit.
  • 16 4
 What?! A broken RM chainstay?! It can't be!
  • 12 3
 hmmm this sucks for RM.. the only way i can see potential customers being won over is if they amend their warranty for the Slayer so it has an unconditional lifetime warranty on the frame.
  • 12 1
 With so much drama in the LBC!!
  • 18 0
 It's kinda hard being an axle made proprietarily.
  • 12 0
 But I, somehow someway, keep coming up with funky ass breaks like every single day.
  • 3 0
 @shawnca7: Maybe I'll, crack a little something, on the Slay-yeah.
  • 1 0
 @freeinpg: and, break a few bones as (yeah!) I slide through
Two on the mountain and the RM aint jumpin
cause my axle aint whole
I got stitches in my arms all swollen and bruised
  • 10 3
 Love a little drama with my cereal in the morn..

I will say, I own a 2017 Element and treat the thing like an Enduro bike and have even done some DH "racing" on it. It's got over 1500 hard miles, mostly XC racing, and as much as I've felt under traveled on stuff I've never lacked confidence in the frame.
  • 2 3
 Totally agreed! I rally the crap out of my '17 element on trails it has no business on and it always takes it in stride. Most underrated downcountry bike out there!
  • 6 3
 So what does that have to do with a 2020 Slayer breaking???
  • 3 2
 @CircusMaximus: ... Slayer's and Element's are both Rocky Mountain branded bikes. I'm saying that through my personal use I still have tons of confidence in their entire product material and manufacturing line regardless of this failure.
  • 3 2
 @CircusMaximus: I thought that was obvious...
  • 11 1
 Good now I don't have to look at a hundred whining comments begging you to put this review out. Thank you pb!!
  • 7 0
 Everybody wanted that rear-ward axle path and now all they can do is complain? Rocky's in-house axles seem garbage, to add another data point my friends hub was destroyed by one (2016 model). It would not stay tight and that's problematic. He replaced his axle with after-market and he's never had an issue again. From what i've seen, which isn't a lot, the RM axles are Chineseium cheese with threads like something from the middle-ages. Sad to see people are actually getting hurt by this.
  • 2 0
 I wonder if his axle could be related to his chainstay yoke splitting in half...interesting.
  • 3 0
 Im with you on that theory. No one probably tests the axles for strength and with that cheap ass Chinese aluminum who the hell knows. If the axles was loose or ovetightened and broke it would for sure cause that kind of failure. With how much force is put on the rear wheel it would have easily caused the chain stay to rip apart. @pinkbike-engineer DO A BIG TEST ON ALL THE AXLES AND AFTER MARKET AXLES ON THE MARKET. It should be easy to grade the aluminum and sheer strength. I bet a lot of them are just shit products.
  • 1 0
 @Meettaco @pinkbike-engineer It's a problem? I am aware of no standard for grading axles like there is for other clamping hardware. The total strength of all these aluminium thru-bolts is probably pretty low, but then it's also about the application as well. Issues such as the thread interface being so poor the axle can easily loosen will increase the odds of an end-user over-tightening. Testing load, tensile and yield strength of various thru-axles would be cheap and interesting.
  • 18 12
 I’m curious if a full bike/bolt check at the top of each lap on these freshly built up bikes is part of this testing regime? As dramatic as this reads it does seem like bike set up should be in consideration as the first place things may have gone wrong.
  • 32 0
 Yes, every bike got checked over every day. This wasn't the first day of testing either.
  • 43 5
 Full bolt/bike check every run? Is this something you do? Not feasible and frankly not necessary if its built right.
  • 6 1
 @lognar: you can give her a little shake and little lift here and there. It's really not unfathomable to do a preventative maintenance check every 2-3 runs when riding really heavy DH. I'm not saying that I'm retorquing, etc, but I def pay attention to my bike and check it throughout the day
  • 9 1
 @lognar: On a fresh build I've found axles need to have and eye kept on them. Lately; mine came loose one my new bike after lap 1 and 2 so I've been hyper aware to make sure. The bike park is a rattle factory so to only check at the beginning of a day of riding many thousands of metres of vertical on brake bumps may not be adequate perhaps. Just a angle to consider. It is the first thing the bike park instructors teach in their classes I believe. I said I was curious, Brian gave an answer.
  • 5 0
 @Mntneer: u know, i give er the old fashion slam test every couple runs and make sure its not getting noisy or feeling weird but doing a “full bolt check” like homie is suggesting is usually considered putting a wrench to every bolt to ensure tightness is unreasonable. Either that or marking every bolt to see if its moved like many of the wc mechanics do. Im sure the testers are pretty aware of preventative maintenance and are keeping an eye on things. no one wants to get chucked off a bike cuz something comes loose
  • 4 0
 @lognar: Can you throw a football over that mountain?
  • 6 0
 If the axle was loose the threads would have been galled/messed up and I'm sure it would have been felt especially when cornering or drive trian acting up. Pink bike guys had it right about the axle. It was either over torqued or a flaw in the axle IMHO
  • 4 0
 I can't help but think that it was that axle. I bet they are using a sub par aluminum on that axle and if they are not cut correctly it can fail... it just looks bad where it broke. The would easily torque the wheel and rip apart. That is tons of leverage. Especially if it is a hollow axle like all of them are - pretty easy to save a few bucks on a cheaper axle - just sayin...
  • 2 0
 @fruitsd79: bet i could. wanna see my mixtape? if only coach woulda put me in...
  • 6 0
 The reality is that this is a sample size of one. ONE failure (though catastrophic) does not mean that the all of the Slayers or even all of Rocky Mountain's bikes are garbage. If the material was the correct production material (which had been properly tested prior to making the final design decisions) and the frame is a production frame then this was likely a manufacturing defect. Does that excuse the fact that someone got seriously injured? Hell no! But this does NOT mean that the company makes bad bikes. It's a demo bike that was loaned out to Pinkbike and what hasn't been mentioned is how many miles were put on the bike prior to Pinkbike's testing.

I also appreciate that Rock Mountain simply took the feedback in stride and didn't try to blow smoke up anyone's a**. I think that admitting that upon first inspection they were unable to provide an explanation but suggest that they will do some sort of failure analysis to get to the bottom of it shows that they are concerned about their product and customers and want to get to the bottom of this so that they can continue to sell products they want to make that are also fun and *safe* to ride.

But the number of comments in here that state that this one SINGULAR failure on one SINGLE model means that people suddenly think that Rock Mountain is a horrible company that no longer knows how to make a bike is just ridiculous. It's perfectly reasonable to watch for Rock Mountain's final response for this and seek out what conclusions they draw and what corrective actions they employ. You should look for this information! I will be!! And hopefully the answers to those questions bolster your trust in the company.
  • 10 1
 I own a 2020 Slayer and its still rolling with no issues.
  • 20 3
 Good health plan through work eh?
  • 6 1
 Give it time
  • 7 1
 Well this review got off to a rocky start.

(can't believe that pun was still available)

Anyway, here's to an update in the future hopefully once the issue has been properly diagnosed.
  • 5 0
 I respect the response of RM but their statement doesn't say anything imo. I's rather seen a a statement that they would investigate the cause of failure (which they could have done by now). Maybe even isse a recall. But hey, it's just a few broken ribs..........
  • 8 0
 ohhh ! i guess the hunter became the prey
  • 12 18
flag WAKIdesigns (Dec 16, 2019 at 7:09) (Below Threshold)
 Like a rainbow in the dark
  • 11 2
 This is not the way
  • 5 0
 The way, this is not
  • 1 0
 U have Spoken.
  • 5 1
 My first instinct is the axle, look where it snapped. Wheel took out the dropout as it separated from the bike on one side. Plus I've heard about dodgy axles in the past, when people have replaced worn-out Maxles with Chinesium versions. Not saying RMs axle is that, but it is a known weak spot.
  • 4 0
 I'm not convinced by that. I think it possible that the chainstay/pivot broke first and the axle broke under pressure as the rear end of the bike separated. Would be interesting to see photos of the wheel too.
Will be interesting to see what RM find out.
  • 3 0
 I have seen axels and even shock mounts yield, but I have never seen them just shear off like that. You are exactly right though from what I can tell. It looks to have sheared the axel vertically on the drive side which left the wheel/axel free to rip out of the other side horizontally. The unfortunate design of that axel is that it’s very thin due to the treading in the area with the most shear stress. Definitely and axel failure though.
  • 3 0
 On my BMC trailfox, one day my shifting when to crap and I felt the rear end acting noodley. Towards the end of my run my freehub started grabbing. I thought it was a roasted hub, but when I got home my through-axle body had snapped in half, thankfully right in the middle and not at the edge. This was a Bitex hub, which in my experience is better than low end Formula and DT Swiss. Long story short, axles failing is probably more common than we would like to think.
  • 1 0
 I had a rear through axle break this past weekend in exactly the same location (Different bike and axle manufacturer). Luckily I was on flat section of trail, so no major damage done, except for some scuffing of the seat and chain stay. Any more force and it would have destroyed the chain stay as it did on the rocky mountain.

In my case the axle had 2 years of use and had come loose on a few occasions (my fault for not checking). The loosening is likely a contributing factor to the failure possibly combine with over tensioning of the axle.
  • 2 0
 I've snapped a maxle exactly like this, so did a friend.
  • 8 0
 Unsure the axle went first but I snapped one exactly like this on my Tr250, also at Whistler, and the frame suffered zero damage. I didn't tomahawk into the weeds either. Rear triangle redesign..that's what.
  • 5 1
 Might be that the bore for the horst link bearings on the chain stay was too small or one of the bearings OD is too big way out of spec? Or someone pressed in the bearing in a very crocked angle damaging the chain stay bearing bore eyelet? Just my theory.
  • 7 3
 Or someone overtightened the axle. I have the previous version of this bike, axle looks the same. 2+ years no issues with the axle, yet a brand new test bike suffered a broken axle... Sure love saying axle, Axle.
  • 10 0
 @bradwalton: it's possible, but unlikely. The threads were immaculate, and the only people to have built that bike were Rocky Mountain when they first built up media samples, and a former RMB technical rep who was helping us with getting the control tires set up. Axle. Smile
  • 11 0
 @brianpark: For what it's worth. One should be able to tighten the living F out of an axle without worry. It just feels safer. Another thing that feels safe...... Steel axles. Is this what we get when we want everything light AND capable of hucking?
  • 3 0
 @bradwalton: I broke the axle on the previous generation Slayer. The threaded insert on the drive-side had a left-hand thread where it screwed into the dropout. If that insert rotated even a small amount, it seized up the axle threads and made it impossible to tighten or loosen properly without stressing the threads. I am pretty sure this was the root cause of the failure on my bike.
  • 9 4
 What about poor old Luca? He gets broken ribs due to this manufacturing fault. Is that just tough shit or is Rocky lining up some compensation as the bike clearly wasn't for for purpose?
  • 4 0
 I am a Little confused. The axle seems to have broke right at the beginning of the threads, so is there no part of the frame that has a seat for the Hub to sit in, you know to guide it into position and increase vertical strength and overall stiffness?

Even with the axle broken if there was a milled channel for the rear hub to sit in the rear hub couldn't really have come out of place bad enough to through a bunch of torque into the lower pivot causing it to explode.
  • 2 1
 Throw*
  • 1 2
 @TheBearDen: Even with a small amount of lean, the force transmitted by the rear wheel would pop the hub right out of the seat. Makes me think back to the horrors of QR hubs (and my then teammate hucking-to-flat his rear wheel out of the dropouts).
  • 4 0
 Had a same exact failure on my niner jet 9 rdo but with the SRAM Maxle. Luckily I didn't crash or break my rear triangle. Called SRAM USA to tell them about it and hopefully get a replacement. Warranty guy got all offended about me mentioning their maxle was defective and would not honor warranty.
  • 6 2
 Bikes break-I've cracked a few frames myself. On a new bike both this heavy and this expensive that's inexcusable though.

At $7k, there aren't any component compromises on this build, yet the bike is still heavy-even for a 29er enduro bike. With such a light build kit (XTR bits, carbon cranks, etc.) that means that this frame/rear shock weights around 8 or 9 pounds. That's enough material to build a bulletproof aluminum frame....period.

Rocky Mountain as a brand big enough that their engineering and design has to be spread across a complete bike lineup, but small enough they don't have a large R&D staff. Big enough that their frames are likely made by one of the high-volume manufacturers in Asia, but small enough they can't afford the kind of dedicated fittings like dropouts and pivot assemblies/hardware.

Pinkbikers don't like to hear it, but unless you're willing to spring for the Gucci tax of a reputable boutique brand, your best bet is to get a bike from the big 3. Bigger engineering departments, better QC in Asia, and proprietary parts where warranted are standard for them. Those frames break too, but much less often and usually with better warranty coverage.
  • 1 2
 "much less often"...
Lol.
  • 3 0
 @sam264: Much less often doesn't mean never. There is no brand with a zero fail rate,and I've cracked Specialized and Giant frames.

Name a brand that touches the big guys on warranty rates.
  • 1 3
 @peleton7:
Just because they have good warranty doesn't mean they break less often.
Carbon reign 2015-2019 frames broke like nobody's business. Anybody that rode one even remotely hard broke one.
Trek chainstays - again ride the bike properly and it WILL break. Yeah they have good warranty, but I'd just rather my stuff didn't break.

I haven't worked at a shop that sells a lot of rockys but I certainly haven't heard about them having many issues.
  • 2 0
 @sam264: What year range/model of Trek's have issues with breaking chainstays?
  • 2 0
 @Edu888:
Mostly 2017+ remedies with crappy ABP bearing seats. The bearings creep out
  • 2 0
 @sam264: Giant sells over 6 million bikes a year. Even if one model had a run of failures, their overall warranty rate is really, really low.
  • 4 0
 Pro riders have been beating the crap out of the new Slayer. There’s been a few on the market now since September. Given this bike broke so early in it’s life and no reports of this failure on any others I’m going to assume it’s a fluke and keep sending it. I bought my 27.5 C70 in September, loving it and no regrets.
While I do think the ‘20 climbs great for it’s DH capability I’ve decided to keep my ‘17 Slayer as well for the more pedally trails. I find they compliment each other well. I have since passed along my DH bike to a young shredder down the street from me as I’d never ride it again. PB saying the 20’ lacks high speed stability. Hmmm. Maybe it’s relative and the other bikes are just that awesome as I wouldn’t say the same from my time on it so far. Perhaps I’m not pushing it to the limits they are. ????????‍♂️
  • 8 1
 What I learned: Reno sucks.
  • 3 0
 Yup, it sure does. Don't come here, the riding is terrible.
  • 9 2
 Agreed.
  • 3 0
 I had an axle break exactly like this in the summer but on a rigid gravel bike. I hopped a pothole and on the next corner when I leaned a bit it just snapped. Had to make a new "axle" out of an allen key my buddy had and we held it in with 4 or 5 zip ties. The allen broke after about 20km and I had to walk out for about 10km until a passerby picked me up.

Good new though, the bike was fine.
  • 3 0
 Never put threads in shear. Is the piece of the broken chainstay holding them in place? Anyway RM should make the shank of the axle go thru both the sides of the dropout and put the shoulder in double shear and put a nut on the outside. Problem solved. The radial thickness of the chainstay material looks a bit thin as well.
  • 3 0
 So if this happened to a consumer, what would RM's response be? Would it be covered? How long would you be without a bike? Ive dealt with some companies that have sent new parts our right away for free (Specialized, Norco) , some companies sell you the part at a discount, and other companies that seem to ignore you and hope you go away (Evil, YT).
  • 8 3
 Haha I broke the chanstay on a 2004 slayer a decade ago just riding off a curb
  • 4 0
 Hang on, that response from Rocky has totally side swiped me! where the fuck do I go now - on the seventeenth day of christmas , 17 Ruptured Rocky's
  • 4 2
 Rocky really needs to sort these problems out. I snapped the front QR axle on my Blizzard fatbike that I only ride in the snow this year. It's also made by RockyMountain. Looks like a similar failure where the threads end imgur.com/P3Q73mD

Also broke the rear chainstay on the same bike in one season riding.
  • 5 1
 A Rocky Mountain break while riding on a trail...???? Where has this happened before?
Oh wait! To me...TWICE!!
My Element AND my Altitude...
Loved the Ride
  • 1 0
 what did your derailleur cable break? lol
  • 6 0
 Bwahaha the quiet troll of Cam Zink is pretty classic.
  • 6 0
 Broke rib mountain .. I’ll get my coat ...
  • 3 1
 If you look at the video, the upper portion of the broken pivot end is fully scratched off paint.. There is a cavity behind the pivot where a stone can get stuck in and rub it broken like that. I think its the only possible cause for this failure, pivot broke down first, then in the jump the rear end twisted so badly that the axle broke down also. (I own one of these bikes so I looked at the construction)
  • 1 0
 Interesting theory!
  • 3 0
 A bike broke. Too many comments to read them all. Did any of the engineers already mention that this doesn't mean much until you test hundreds of bikes for each model? Oh well. It's Pinkbike. It's entertainment, not science.
  • 3 1
 It's obvious what happened here. Rear axles do break...have broken my rear axle on my IBIS 5 times in 4 years. In this case the axle threads didn't completely shear off and when the tire/wheel cam down, it tore the rear mounting point and wrecked the pivots from the massive downward force as the threaded portion of the axle finally gave way. Shit happens...move on.
  • 4 1
 I love how this is all innocent like; "Ooooo we were gently hucking this at Whistler bike park and all of a sudden it brokey." No mention of the hard case on the Pemby train gap or something...
  • 2 0
 This failure makes me wonder if I need to tear down my bike after every ride. Up until now I’ve blindly assumed that today’s bikes are massively overbuilt for my average skills and duty cycle. I don’t torque my axles, I don’t check all the suspension and axle pivots after every ride. I’m not a pro racer so I shouldn’t have too. I’d prefer to error on the side of being overbuilt, I’ll take the extra 1.5lbs to make it unbreakable.
  • 2 0
 Pivot seems to do "overbuilt" correctly.
  • 2 0
 @JohanG: agreed, I also feel pretty safe on Devinci’s
  • 5 3
 So, no video of the landing and crash....that axle looks like it wasn't tightened correctly for it to break like that. PB can talk about having a Professional Mechanic, but ya know what.... that's a weak statement. We've all seen "professional" mechanics at shops and such not tighten things correctly and a bike rolls out of the shop with an issue. The mechanic could have easily not done his job, because that happens.... But, this feels more like someone has an agenda at PB with the brand. Pretty sure there's a mod on here who used to work for that brand right? I mean damn, Rocky has guys like Storch and Vanderham pretty much pushing that bike and no failures. This axle break looks like PB really F'd up and didn't tighten things properly, but now they'll say a freak one-off is this big disaster and no way had any fault on their end... I mean chain-stays break on bikes, happens with every brand. Shit can break no matter how much testing is done. This particular incident just looks like a freak one that probably could have been avoided if the mechanic did his job. How do we know the mechanic wasn't having a few beers or hitting a vape pen, ya know...just having a good time with the boys and thought he tightened that down correctly. If this was happening left and right, ok....put the brand on blast. But a one time incident that can't be replicated....seems to me like someone here has an agenda. I'll bet Rocky wouldn't pay PB enough money, where if this was Trek or Spec, etc.... they would line their pockets well and PB wouldn't over-dramatize things on those brands.
  • 4 2
 Wild. Bikes break, they all do eventually. While it's not great it happened this quickly, it's good to see how different brands respond to breakage. I can honestly say if I broke a bike, I'd hope it was a Rocky!
  • 5 2
 I’ve had a C90 all fall, best bike I’ve ever ridden. Bomb proof. Just wonder how long Pinkbike had bike before test...did they torque that axle to specs?
  • 1 0
 Why the best bike you've ever ridden? Honest question as I am considering getting one despite this nonsense...
  • 1 0
 It climbs super well, and the geometry/suspension make it ready for anything. I live in nv so it’s the perfect bike for area. @bmcknight:
  • 2 1
 Was the axle torqued to the specifications using a torque wrench? It is too common that a long armed allen key is used to over torque the axle (or other) bolt by hand. The Slayer is a slick looking bike. I'll be taking the torque wrench to my axle bolts after cleaning and regreasing. Also a good time to check the other bolts.
  • 1 0
 I never torque mine to spec. Spec seems way too tight. Like, I'm cranking on the thing, and cranking, and cranking.
  • 2 0
 2019 RM Instinct specs are front axle (kabolt) 17nM and rear axle 10nM. 10nM is snug but not overly tight compared to 6nM for the average stem bolt. 10nM is easy to exceed by hand without a torque wrench. This axle failure made me retorque my bolts and reminded me of proper pivot and bolt maintenance. Glad the rider was not hurt further.
  • 3 2
 $5 china axles machined improperly for the strength needed, china assembly of bearings in seatstay, someone went a little spicy on the press. Axle either too tight or stressed from multiple wheel swaps.

Lots of things cause failures. Funny how almost 100% of mountain bike production has gone to china but bikes keep getting more expensive...
  • 3 0
 I don't know much about import export stuff, but I'm confused about why Canadian bikes seem so expensive. USD is always stronger than CanD. Why is this bike $8K US? The next one down is $6K and isn't all that impressive, crappy wheelset, basic rotors. It's like that with all the Can brands. Frown
  • 1 8
flag JohanG (Dec 17, 2019 at 5:19) (Below Threshold)
 @mybaben: They pay a lot in taxes for their socialist state. It greatly decreases efficiency in the economy.
  • 1 0
 @mybaben: Kona especially!
  • 1 0
 @gorideyourbikeman:
Are you saying Kona is Canadian? Cause it isn't, just about 40 miles south of the border
  • 1 0
 @Chris97a: I'm saying Kona sucks, and they are Canadian. I don't care what you say. clearly and unfortunately Canadian.
  • 1 1
 @gorideyourbikeman:
Cool I'll go drive over to their shop and tell them they are actually in Canada.
  • 1 0
 @Chris97a: they'll tell you they know their roots were started in Canada and then probably call you stupid. Rocky's bikes are made in Taiwan. I guess there a Taiwanese company.. cool logic.
  • 2 0
 @Chris97a: from wiki... and widley known to anyone avid abut mtb "Kona Bikes is a bicycle company based in the Pacific Northwest. The company was founded in 1988 by Dan Gerhard and Jacob Heilbron in Vancouver, British Columbia, Canada. Still owned by Gerhard and Heilbron, their world headquarters are located in Ferndale, Washington, with Canadian distribution offices in Vancouver, and European distribution offices in Geneva, Switzerland."
  • 5 0
 RM, good professional response.
  • 1 0
 I broke couple of axels on the Street/Dirt bike however they were part of the hub itself (they required higher torque), however never saw this kinda failure on the bike that have bolt through design, I could not even imagine
how you can over tight this type of axel?


on the other side all bike brands have frame failure, some of them have shitty excuse some of them nice warranty
  • 1 0
 My RMB fatbike's axels were consistently loosening over the course of any ride on me. Fatbike no putting big stress there either, and a HT so I got away with it. Aftermarket axel's remedied issue. I know that is where I'd point my finger as PB has already hypothesized. Bad axel/thread tolerance? Bottom of a run might have been thread backing off... Could be a very easy fix for RMB if better axels needed both in parts and labour… unless bad axels have already damaged frames. Great company supporting some good content/ athletes, with good focus on their method for their trails/market...not just following trends... but a tough moment for them here. Study Storch's 'raw' edit bike vs. this one! His sponsors have him on different axels? Loctite? Regular retorques?
  • 1 0
 What axles did you replace with? I have a Blizzard as well with the same problem. I broke the front axle and replaced with a dtswiss throughbolt. Not sure what to do with the rear though.
  • 1 0
 I'd like to know which manufacturer never had broken frames. Here the only difference is that there is a testimony and a claim against those who have been hurt, in real conditions the RM, like all the others, would not even have replaced the broken parts under warranty.
  • 1 0
 After reading most of the comments pretty much all is said what is to be said. RM, but not only RM has to be taken their responsibilty to the riders of their bikes. All brands have to encounter with malfunction of parts or breaking of frames with sometimes disasterous consequences for the rider. It's in favour of the brands that the odds of being confronted with claims are relative low but meanwhile all riders are playing sort of russian roulette!!!!!!!!!!!
  • 1 0
 From my limited understanding of physics and material science, option one is: it looks like the axle may have been somewhat loose, causing the weakest point of said axle (the threads sitting in their bore) to fail, thereby transferring forces to the pivot, that the pivot was not designed to withstand.
Option two would be: the axle threads were improperly machined (too deep or too long), thereby causing the threaded area to be the only supporting element for the forces coming from the wheel --> axle failure leading to pivot problem mentioned above.

My conclusion is that the threading on the axle was either a) too long, or b) cut too deep. Again, based on my limited knowledge this is just a theory, but when threads on a bolt fail it's typically because the bolt was loaded in a way which bolts don't deal with well, which is a powerful radial load.

This is an issue which caused a rider to crash and get injured and therefore a catastrophic QC fail. Could have been life threatening. It happens in every field, but there's a reason that FMEA and other QC systems exist.

On the other hand, this could have just been bad luck.
  • 1 0
 "although it's not quite stable and planted enough to earn it the mini-DH buzzword - it feels more like an enduro bike with a little extra travel"
And THIS is why Rocky Mountain needs to keep the Maiden in the line up! Long live the Maiden!
Sorry for Luca, sorry for Rocky Mountain. Certainly a surprise. Any bike can fail, but didn't expect it to be from this brand and especially this model. I've had many a Rocky Mountain, and never had anything major like this happen. It doesn't make me any less apt to get one, I'm currently hankering for a Instinct to compliment my Wreckoning.
  • 2 0
 Lol, everybody is commenting about the bike. Nobody gives a f$ck about Lucas ! Dear Lucas, I hold my glass of wine to you sir. I wish you to recover fast without consequences. Buy a Kingdom Hex, it won't happen again. Cheers
  • 1 1
 If you really cared you might have spelled his name correctly...
  • 2 1
 Too bad Rocky Mountain... Feeling sorry for you.
I still ride my old-school 2008 Slayer SXC and it didn`t break yet. Still a smooth clockwork... but it was aluminium era!
You`ll fix it out, for sure ;-)
... and if Pink Bike would have tested the aluminium version, what would have happened??

Also Pink Bike: watch out your language; so-called experts in pampers like you shouldn`t talk like that.
  • 2 0
 The rear triangle that failed (as well as the axle) is shared across both carbon and alloy models.

Kaz finally grew out of pampers last year.
  • 3 1
 I demoed the very same bike and liked it, so much and my son tested Thunderbolt And he loved it, and we bought one for him. Hope that does not brake as well. There should be an inventory of these kind of failures
  • 1 0
 I got a thunderbolt A50. AMAZING bike. don't worry about it breaking, its a different design and a super strong bike, not one report of problems with them! Enjoy!
  • 1 0
 Maybe it has been stated but over/under tightened thru axle? The outer most contact point axle-to-frame should be on solid shoulder and not threads yet the axle broke at the threads in what appears to be the stressed area between the end of the female threads and where the solid shoulder should be supported by the frame. Most likely a broken axle that caused the break. If the shouldered part of the axle is slightly short (as in, engineering error or manufacturer of the axle error not following required specs exactly) the course threads would be massive stress risers in a high stress area.
  • 1 0
 The axle should only be loaded in tension, with the wheel load being borne by the hub end caps. Requiring the through axle to be bottomed out would require much tighter hub tolerances than are remotely practical, resulting in hubs rattling in the dropouts if the axle is half a millimetre too long or bearings getting mashed if the hub is fractionally too wide.
  • 5 0
 -skid more!! -RENO SUCKS Interesting background notes.
  • 1 0
 I’m going into the garage now to check my through axles. I agree though that the axle is a likely culprit. If you watch slow motion videos of pro riders going a little sideways those back wheels are all over the place. A loose axle would have a lot added stress in a situation like that I would think.
  • 1 0
 Not sure how I feel about Rocky Mountain bikes..?? I owned a 18' Rocky Mountain Altitude and the frame failed completely at the head tube maybe my fifth ride! Thought maybe it was me, but this is now the fourth post I've seen about a bad failure. Big compression on a jump and the thing exploded like it was shot by a 9mm. So much for Smoothwall Carbon and top of the line construction...
  • 1 0
 howd it brea? what were you doing? curious.
  • 1 0
 rockys have lifetime warranty's on aluminium frames here in alberta anyways.
  • 1 0
 @gorideyourbikeman: came down hard over the head tube on a big jump compressed the front end weird. Wish I could share the photos
  • 1 0
 @gorideyourbikeman: yeah was carbon ended paying for a crash replacement
  • 1 0
 @Railsmorethanberms89: oh shit! That must of been devastating... damn man sorry to hear!
  • 1 0
 Is it possible that the pivot rotation is somehow over tightening the axles?
I have seen a few Rocky axles in their FS bikes become overly tight and in extraction this is exactly how the axle brakes.
I believe Rocky also produced a video on how to effectively remove an over tightened axle.
Perhaps that impact was enough of a forceful test on the axle after the threads had locked to spiral snap it?
I am curious to hear the actual outcome of Rocky's investigation.
  • 1 0
 The frame material at the busted droput looks so thin it's no wonder it broke so catastrophically whether the axle, frame, bearings, or anything else snapped first. The droupout looks to be super thin and weak to me, I've destroyed far more robust aluminum bike frames and parts. If the axle broke first and the dropout stayed intact the rider may have been able to ride out the failure. That would be worth the extra weight nto me.
  • 1 0
 maybe they shouldn't drill that thru axle out all the way to the threaded end, or maybe they should pin 30mm of metal in there to beef it up. It's an obvious enough fail, axle snapped ripped through on other side due to leverage.
  • 2 0
 Maybe you should've had a assembly checklist to make sure all the axles were tightened properly. QC is slipping at PB, and at the brands expense, next time ride them all with loose axles and conduct a "durability" test.
  • 1 0
 100% this failure came from that axle, the failure from the frame was secondary after the Axle failed. I would love to see detailed up close images of the fracture surfaces of the Axle and frame.

That aluminum axle, especially if it had a lot of tire changes, had been tightened and loosened too many times. Very likely had been tightened by hand much higher than it's torque spec. (with the assumption that it had a properly calculated torque spec ) It met it's fatigue life, and began stretching at those last few threads. Once that began, the axle was doomed.

It's possible the ALum axle was under spec'd, or bad heat-treatment, but more likely it had been over tightened way too many times. I would guess a close up of the fracture surface will look like a textbook example of this particular failure mode of threaded fasteners...

This isn't Rocky's fault. (although one could argue they need more margin in their safety factors, perhaps,) But the fault of one of the people who ever touched that axle...
I have seen the exact same type of failure on bolts just like this in my professional life, I'd wager a fine bottle of scotch this failed because the axle was over-tightened too many times.
  • 1 0
 P.S. If @RockyMountainBicycles has called this out as the failure mode yet, they are being polite to the ham-fisted "mechanics" that worked on this bike!
  • 7 3
 Just recently I snapped a chain stay on a 2018 AL element.
  • 7 4
 Broken frames used to be Rocky's defining characteristic. Too bad it took out the test rider.
  • 5 6
 @FarmeR57 I think you have them mistaken for Kona. Broken frames have never been Rocky's "defining characteristics" as you say. Sure they have had a couple breaks here and there but nothing compared to Kona.
  • 4 0
 @mhoshal: In my experience I would disagree and would also put Specialized and Trek ahead of Kona
  • 1 0
 verbal diarrhea.
  • 2 1
 Looking at the direction of forces applied, and the twisting element, it makes more sense that the Horst bearing failed first, then as the rear twisted it snapped the axle at its weakest point.
  • 1 1
 i had an almost identical problem with my 2019 altitude on Dirt Merchant. I only snapped the seatstay and it didn't result in a crash but still pretty annoying. rocky mountain was really good at warranty things and actually sent me two replacement parts. but still it wasn't a drop that should have been a bike killer
  • 11 8
 Rocky, how can you honestly say the bike is safe to ride? Seems obvious that just isn’t true.
Time for a recall.
  • 7 2
 One failure means they need to do a recall?! The fact that someone got hurt because of a failure sucks, but that doesn’t necessarily mean that every other frame out there is prone to the same failure.
  • 1 3
 @pacificnorthwet: or does it? How would you know?
  • 2 1
 @CircusMaximus: why assume the worst?
  • 1 1
 @gorideyourbikeman: it’s not really an assumption is it. The thing broke. Badly. It’s a brand new model. One may want to err on the safe side. Seems reasonable to me. Why assume it’s a one off and potentially have more dangerous failures?
  • 2 1
 @CircusMaximus: because they have pro enduro riders shredding the crap out of these outstanding bikes. an axle snapped. get over it. that's a pretty clear assumption you made.
  • 1 2
 @gorideyourbikeman: too funny. Can’t you see the assumptions you are making. You have zero fact to support that they axle snapped’. That may have been a product of the frame failing. Even RM doesn’t know that yet. So let’s talk assumptions..get over it man. Hahahaha not trying to start an argument, just stating my opinion. Pretty sure opinions are ok on a forum.
  • 2 0
 @gorideyourbikeman: haha not a boomer...those are parents.
When out of valid arguments go with the latest saying huh. Smile
  • 2 0
 @CircusMaximus: I don’t know, Pinkbike doesn’t know, and Rocky Mountain doesn’t know. That’s why Rocky Mountain is trying to analyze the broken frame to figure out what happened. If it is an issue that they are concerned will impact this entire line of bikes they will find the issue and take appropriate action. They don’t want people getting hurt from their bikes failing, even if the only care because they don’t want to get sued or lose sales.
  • 1 0
 @CircusMaximus: no your replies are long winded and i dont care.
  • 2 0
 I'd probably still consider buying a Rocky Mountain. Not a Slayer (I don't need that much bike), but one of their other models.
  • 3 3
 I rode a Rocky Mountain Element for a little under a year and had nothing but problems with it. Granted, the majority of failures were in the components, but the derailleur hanger bent REALLY easily and was ridiculously expensive to replace direct from Rocky Mountain. Their customer service was pretty poor as well, in terms of responsiveness. They did their best to force me to go to the shop rather than fix the bike on my own terms. I was not impressed. Got rid of that bike and moved on to an Intense. SO MUCH MORE DURABLE and awesome customer service. Never going back to Rocky Mountain.
  • 2 0
 so rocky designs derailleur hangers now and it's their fault? get a grip.
  • 2 1
 Enduro/DH focused bikes should all have thru axle pinch clamp bolts on both the rear triangle and the fork IMO. They do come loose and it adds extra safety for a couple of grams. You've gotta check the torque otherwise.
  • 1 0
 I wonder if the axle had actually been broken earlier in the ride, and the bike riding on the broken axle eventually weakened that chainstay pivot until it eventually broke on that last hit?
  • 1 0
 Interesting. There was a problem with early Hope Pro hubs and Maxles. Hope switched to Pro2 and that fixed it. I broke 2 on my Orange Alpine but you could hardly notice. Swing arm made from girders in Halifax????
  • 1 0
 What's painful when you watch the video is... the Mikes are actually scared to ride it until they know what happened. Makes you think about test riding anything - how do you know it won't break on you and kill you?
  • 3 0
 AXLE: the part on a wheel

AXEL: Dude’s name in German and a few other languages.

Güd spelling is for loosers
  • 1 0
 Or...
Aluminium yield strength / machine cut thread X torque X force (huck on A-line) = that axel

Cascading Effects... busted up chain stay

Soon to follow- torque specs printed on all axles.
  • 1 0
 the problem was spliting the links after breaking the axle. solution, even if not simple, lock that eye mount on chainstay with seatstay mount. If axle breaks it still hold intact.
  • 1 1
 As a tradesman , I look at the axle and too me. That,s the failure point. Course pitch sharp V 60deg threads in aluminum . Not a good idea. As for the comparison between Pole and Rocky . I didn't read all the BS about it. I just looked at the images . That alone showed me they were aware of a potential issue on a trail bike. That part fractured doing a flat drop to pavement. Not shredding a trail the bike is designed for. Going back the the axle , undercutting a thread like that. Is a built in shear point. I have done this hundreds of times machining industrial parts. This is done to allow certain parts to be removed after a failure.
  • 1 0
 Who checks the bikes over before sending it down a line? I'm wondering if the rear axle was properly tightened. This obviously sucks for RM and makes me question durability. Can't even blame carbon on this one
  • 3 0
 Wonder is this happened to a normal person, what would they say for warranty?.
  • 3 2
 Somethings fishy with this. Pinkbike should not get their test bikes directly from the company. They should just go to a dealer, and anonymously buy or order a bike for their test. It would have saved the Pole fiasco.
  • 1 0
 To reduce confusion in the future, consider refering to these types of failures using proper engineering terminology.

" Bike experienced a RUD event when....."

RUD = Rapid Unplanned Disassembly
  • 1 0
 I think companies should send you a complete bike AND a complete frame to insure their models get tested completely so you can sign off on them... if you don't end up building up the frame no biggie...
  • 11 7
 Cracky Mountain
  • 2 1
 Everything breaks- in this instance it just so happened on the largest stage for mountain bikes.

Will be curious to hear what the follow up will be?

Crash replacement?
  • 3 1
 Letting them off too easy. I like RM and have owned a few but this is a problem.
  • 1 2
 This one is weird.

If the axle were the cause wouldn't the break have been on the drive side as it was the only side still connected?

I did break an aftermarket axle like that once when I hit a stump. I had over tightened it as it kept coming loose (before I discovered lock-tite).
  • 4 0
 Axel broke drive side, rotated out and ripped out of non drive side
  • 2 1
 Wow really looks like the Horst pivot failed then the axle broke. Seems like the axle would be to blame but look at how the bearing bore is pulled apart!
  • 3 0
 Finally! THe enduro bikes!
  • 2 0
 Who cares if it broke because it has a water bottle mount. You can take a shot and calm down.
  • 3 0
 well that was a "quick release"
  • 1 0
 @mikekazimer @brianpark @mikelevy @sarahmoore

Is there going to be an overall round up on your favorite bikes regardless of category?
  • 2 0
 Just the round-tables within the categories. Because of sizing and logistics most people only did one category—so they could get the most amount of ride time on the bikes they were responsible for testing.
  • 1 0
 @brianpark: shame but fair enough.
  • 1 0
 @brianpark: Have you guys given any thought to a long term test the way car magazines do it? Maybe ask the winners of each category to send over one of each size so everybody can have an opportunity flog it for a year and let us all know what they're like to live with and how they ride on some different trails, maybe even with the various other parts you guys get to test.
  • 1 1
 I mean, there are such things as manufacturing defects and material failures. Any one of the axle, threads, pivots in there having one of those seems like it could have caused this no?
  • 3 0
 SLAYER. It will kill you.
  • 2 0
 Can you swap in a dt swiss axel? That seems like a no-brainer if you own one of these bikes
  • 2 1
 Now would be a good time to sell one of these bikes if you own one - else it'll be like trying to sell a 26" bike in 2016 ha ha.
  • 3 0
 You just might not wanna put it on Pinkbike buy and sell.
Oh and can somebody remind me to get good enough at biking to just *warm-up* on dirt merchant ha ha.
  • 4 1
 This would have never happened with a 135mm quick release axle
  • 1 2
 Old School QR axles break all the time-or the wheel flexes in the dropout and ruins the frame.
  • 2 3
 First of all a friendly greet for all the Bikers,

I don't usually comment on posts, just read them.

But I think it ist better do show some compassion for the people who buy bikes for 4-5-6-7-8 K, and thann something like this happend.

It was the same when the yt launched the Capra cf, 2014 the frame was broken on the isgs chain holder.

One thing is a fact, the big companies, no mather what do they built, they do not test anymore that good their products,

Couple of hours on a normal bikepark, no big gaps, no pro riders, and than on the market.

It's all about fackin money ????, money and again money ????.

It's pretty sick to watch your bike completely destroyed from a hospital ????....

So that's all folks.
  • 2 0
 I feel sorry for the tester, broken ribs ain't fun, will he get workers comp?
  • 1 0
 No way I'm riding as hard as these guys, but has me thinking that maybe my Process 111 shouldn't be taken to bike parks anymore, haha.
  • 3 0
 Rocky with the quickest release axle in existence. Rockshox are panicking.
  • 2 0
 Back in 2008 these chainstays wouldn't even pass an obligatory visual stress analysis because they look too xc.
  • 1 0
 Should have said - you could only really tell when you took the wheel off to investigate why things weren’t working so well - the cassette fell off in your hand!
  • 1 0
 I'm flashing right to Simmons in the prototype shop "we need more gusset plates"..... I still want this bike......can't help it. Did this happen on Friday the 13th?????
  • 2 3
 I think the series of events leading up to the catastrophic failure are backwards. I can't see that chainstay pivot failing like it did as a result of the axle snapping, I think the wheel would get cock-eyed instantly and if there was a pivot failure it would be on the drive-side. With the axle broken, there's not much/any load on that NDS pivot, conversely there's be a huge load on the DS and you'd likely see a bent/broekn axle there.

If you reverse the series of failures it makes much more sense. Something about that pivot failed and as it started separating it sheered the axle in the process. Hard to guess if it were a loose/out of tolerance bolt/chainstay, or simply not enough meat around the bearing. If I had to put money on it, I'd say something was out of spec with that pivot bolt assembly which lead to a fatigue failure somewhere further up A-line and and ultimately a catastrophic failure right about where poor Luca hit the ground.

Heal up Luca!
  • 3 0
 If the axle has snapped at the threads, it's not going to cause a drive-side pivot failure because the wheel is no longer connected at the drive side.
  • 1 2
 @dsut4392: Total brain fart on my part, was thinking the axle went in from the DS, unlike pretty much every bike ever where it gets installed from the NDS, however I still think the snapped axle is the likely result of a blown pivot, not the other way around. If the axle snapped and applied enough force to the NDS seat-stay rip it up and out of the pivot, I'd expect to see damage to the axle as well as the drop-out. I'd also expect to see a twist in the seat-stay, hard to say from the pictures, but it appears to have, if anything, bent the wrong direction.

One way or another something is fishy here, and RM's response is totally wrong IMHO. If a failure of this nature occurs and you have no idea how or why it happened, unless you're damn sure it was user/installer error, you don't get to claim the thing is perfectly safe to ride and it's no big deal. The fact that they brought it back for testing to see if it was an early model that missed heat treat is a huge red flag as well. How is that even a possibility?
  • 1 0
 There is a twist in the seat stay, and in the right direction that you're thinking. RM has tested these bikes so much that they can say that its safe to ride. I'm pretty sure its the axle that broke, maybe it was overtightened too many times. These stealth axles are very easily overtightened. I think pinkbike wanted to see if it missing heat treating or something, they didnt mention that RM would've told them so.
  • 1 0
 @Jukis: The only twist appears to be in the wrong direction, and the material on the CS pivot looks to be deformed the wrong way. If you're viewing it from the front of the bike, the twist should be clockwise and it appears to be tweaked counter-clockwise. That's how I see the photos anyway, without a straight on shot, it's impossible to say for sure though.

I disagree with RM's assertion that the bike is totally safe. Clearly it broke, so either their testing is inadequate or their quality control is. You can't claim the bike is safe if this example was within tolerance and failed the way it did, and you can't claim the rest are safe if this one was out of tolerance but somehow got through QC. If they suspect failure of the axle due to improper installation, that's an easy one to test, and being a brand new bike with a brand new axle that wouldn't have been removed and re-torqued more than a few times fatigue shouldn't have been a problem unless Pink Bike's mechanic was really ham-fisting the thing.
  • 1 0
 Just eyeballing that broken part the wall thickness looks too thin. Some enginerd spent too much time using FEA software to save 20g. Beef if up.
  • 2 1
 Except if you follow the Rocky Mountain Bicycles Owners Club group on facebook... this sort of failure is rather common for them.
  • 2 0
 AFAIK this is the first of this kind of failure they've seen on the Slayer. (not the broken axle, but the pulled-apart chainstay/seatstay pivot)
  • 2 0
 @brianpark:

The pulled apart pivot is a consequence to the axle breaking and the wheel twisting. It started with the axle failure and progressed from there. Wiithout the axle snapping upon landing the jump, there isn't the energy to twist the wheel enough to yield failure the pivot.
  • 1 1
 Except that pretty wrong and a broad statement to make. go find failures on other brand forums. all over. Heck I googled "Norco broken frame" and got pics and videos of santa cruz's with broken triangles. jeesh.
  • 1 0
 @deeeight: Agreed. Judging by the photos and description of the failure, this seems like the most likely scenario.
  • 1 0
 Hello bikers.....
First of all bikes are not indestructible .......
Then.......what about considering the option of a really bad landing ?
  • 3 0
 “Ouch”. Rip. Slayer.
  • 1 0
 it feels more like an enduro bike with a little extra travel.

İ mean its a enduro bike
  • 3 2
 Wanted to like this bike. I still want it to be my next bike. F***. Heal up Luca.
  • 2 0
 oh but the Rune drop out didn't break.
  • 4 4
 "Our current working theory is that upon landing, the Rocky-branded axle snapped at the driveside threads"

nah, it's frame sucks!
  • 1 2
 quite the assumption. what do you know about R&D. rocky leads the pack in a few ways so......
  • 2 0
 How/when will we know when it's fixed?
  • 1 0
 I just want to know were I can buy a Pink Bike water bottle, it's not in your online shop. Thanks!
  • 3 0
 Buy Devinci
  • 1 0
 On other news maybe downhill bikes still have place to do some stuff, ya know they have pedals and transmission too...
  • 1 0
 @pinkbike the wheel in what condition is it?
because if it is not destroyed there is to be complimented the RacaFace!
  • 1 0
 yeah, but it comes with a spirit guide! i can quit going to yoga class if i get one...
  • 1 0
 and the spirit guide will come in real handy if your injuries get you killed!
  • 2 0
 Shining a light on the darkness.
  • 1 1
 When i was a boy my dad used to say " you ruin everything you touch" if he was still alive he'd probably say the same to Pinkbike.
  • 2 0
 Was Kazimer an MMA fighter?
  • 2 0
 This Slayer has been slayed
  • 2 0
 But you can fit a water bottle !
  • 1 0
 If it was a broken Yeti, the flame would go to sky, but it's RM, they will solve it everybody is fine with that :&
  • 2 0
 I guess the slayer got slayed
  • 2 0
 I just thought the one last year looked cooler.
  • 3 1
 Oooof. Shoulda used carbon Smile
  • 1 0
 For the axle?
  • 1 1
 $8000 bike should be spec'd with higher quality parts. most of the parts, like the xtr drivetrain were higher quality parts.
but then RM spec'd a house brand axle?
  • 1 0
 Nice going Mike! But this is not what we were looking for when we said we wanted 26"!
  • 1 0
 So what I got outta this is that...RM Slayer might be a good bike, we don't know yet BUUUUUUUUUT Pole really messed up lol
  • 2 0
 Rocky Mountain can save this one, just manufacture the PipeDream!
  • 2 0
 Everyone knows the Russians were behind this.
  • 1 0
 Clearly rocky has not designed a stiff enough rear end, they need super boost 157
  • 1 1
 "Clearly unsafe terrible design. Stay away! Never use!" Slinks off to buy sell area exitedly wringing hands together looking for deeply discounted slayer to buy and ride...)
  • 1 0
 Wow! Hats off Pinkbike. My trust in you has just been restarted after watching this review. Well done.
  • 1 0
 If it was a carbin bike lookout!, Because is was aluminum, o geeze we don't know what happened???
  • 1 0
 No wonder why that bike was unstable at speed! I still love Rocky mountain and ride a thunderbolt- my bike is awesome.
  • 1 0
 Sooo, Have we had an explanation for this failure yet?
There are rumors of a loose axle being the fault.
  • 9 9
 Pinkbike: Can we have some bicycles for field test?
Bike Manufacturers: Lets send them some bike made of tofu.
  • 1 0
 Release-the-enduro-field-test
  • 1 0
 I busted a Maxle in the exact spot on my old Rune.
  • 2 0
 What was the resulting damage?
  • 1 0
 @PHeller: Just had to replace the axle and true the wheel. Mine snapped in a corner so I got wobbly and was able to stop. The walk to the car was long though.
  • 2 0
 JRA
  • 1 0
 My RM Flatline broke at the drop out too!
  • 4 7
 1) The broken axle theory before the big failure doesn't fly with me. When I broke an axle in a similar manner (I had overtightened the axle and actually heard a click/ pop noise while tightening it) the bike (an SB5.5) sagged to an absolute un-ridable condition immediately and had no damage besides the axle. The Rocky all came apart in one landing.
2) Always use a torque wrench on your bike and ALWAYS use lock-tite on your axles. EVERY SINGLE TIME. They simply don't stay on tight at the torque values allowed.
3) I've always dug RM bikes and they are a brand I'd have had on my radar. IMO RM needs to send new chainstays and beefier rear axles to every current owner of these bikes. The chain stay should absolutely have lugs to hold the hubs in physical place (as should all bikes) so that the axle locates the rear wheel but the aluminum chainstays, not the axle, is where the force from rear suspension compression goes.
4) Saying there is no issue doesn't give me the warm fuzzies and this isn't a bicycle I would ride at this time. I already got ERed when a motorcycle part failed and don't need any more of that in my life.
5) Even though Pole's response was BS, at least riders can rest assured they are changing the design which failed.

Good luck Rocky Mountain, this is going to hurt.
  • 5 0
 Just to be clear, our theory is the axle broke during the same impact. We'd definitely have noticed if the axle was fully broken ahead of time, especially on a high-compression trail like A-Line.
  • 1 1
 There is no way that axle would've broken first. Its obvious that the pivot end has broken down earlier. Quite possibly from a stone thats been stuck because the paint has been chipped off from the bottom side, the crash itself wouldnt scratch the paint from there. Now only thing remains is to think how to stop any rock from getting in behind the pivot? Maybe some silicone caulk into the cavity? - Owner of a 2020 slayer
  • 2 0
 For point (1): Your SB5.5 had/has a monocoque rear. I'd think that that's inherently stronger than any four-bar design when it comes to landing with a loose/broken axle, or landing and breaking the axle at the same time. Once the axle is broken something's got to give, and with a four-bar that's the next weakest point - in this case the bearing seat on the chainstay.

Regarding (3): As far as I know all RMB designs, as practically all bikes, have the rear wheel slotting vertically into the dropouts. Once the axle is loose - or broken - any landing that's even minutely off-center will cause the rear wheel to rotate out of the frame anyway. In this case the axle was broken on the right side, so the rear wheel twists out of the dropouts in a clockwise fashion (assuming you're standing behind the bike).
  • 3 0
 Never use locktite on an axle or a pivot, they should be greased and torqued ... back to mechanic school for you!
  • 2 0
 @nurseben: I don't know man. Axles, front and rear, rarely make it through one single ride without coming loose with grease at the max allowable torque rating. Brake rotors, same thing.

Tried overtightening bolts to get thru a single ride without them coming loose, and the parts then just broke, frankly in a manner not dissimilar to the photos of the RM axle.

I was told to lock-tite them and since, no more problems. They make a thread-locker that just puts a bit of dry rubber on the threads so it doesn't back off, and that's what I use now.

Your experience may vary, but I'm sticking with it.
  • 1 0
 @SunsPSD: Nothing wrong with putting locktite on threads. Teflon tape sometimes works too.
  • 1 0
 @nurseben: I think I always see the blue (weaker) locktite when removing factory installed pivot bolts, but never heard of it on an axle.

@SunsPSD: yes definitely locktite rotor bolts, and caliper bolts.
  • 1 0
 its the new axle standard Buust
  • 1 0
 @Chiliwacker #justiceforluca
  • 1 0
 Not even the Spirit Guide could keep the chain on.
  • 1 0
 That's one way to fit another water bottle!
  • 2 0
 Is it chinaluminium ?
  • 1 0
 Oops. I’d be faking pissed... broken ribs are no joke. Too damn painful
  • 1 0
 So this bike is ugly and it broke...! Where is my wallet?
  • 1 0
 Just gonna send it, it's gonna be ahh good day !
  • 2 0
 Oh SNAP - BwaHaHa!!!
  • 1 0
 This will also break the comment section!
  • 1 0
 600 comments?!? wtf, people?
  • 1 0
 WOAH...doesnt matter what anybody says...Major KICK IN THE NUTS for RM Frown
  • 1 0
 Maybe it just broke. Sometimes things break............
  • 1 0
 This is why qr is better :p
  • 1 0
 Press-fit axles will resolve this!
  • 1 0
 My Slayer C70 is awesome.
  • 1 0
 Where is the result of RM's analysis?
  • 1 1
 Now it’s clear why the slayer survive on it is a big luck
  • 1 2
 Apparently the slayer is an amazing bike tho. Its unfortunate that it broke......
  • 1 0
 Harsh
  • 2 3
 If your bike swing arm is aluminum, you don't have the right to classify your bike as carbon!
  • 7 0
 Ok carbon police.
  • 1 8
flag brookland27 (Dec 16, 2019 at 19:45) (Below Threshold)
 Why do you suppose a ton of bike companies do this?????...... Oh it's because despite your delicate sensitivities carbon isn't as durable as proper aluminum.
  • 1 1
 No bike is unbreakable it can happen to any bike
  • 1 1
 no matter the brand or frame material...anyways will break
  • 1 0
 A Frame of any material might break after years of abuse, shouldn't break in well under 1 year, no?
  • 1 0
 Ouch
  • 1 1
 Shoot
  • 4 5
 still one of the sickest looking bikes on test
  • 1 1
 Made in Taiwan
  • 6 9
 ITS HERE!!!! ITS FINALLY HERE!!!!
  • 5 1
 Boeing Max 8?
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