X-Fusion Prototype Inverted Fork - Eurobike 2012

Aug 29, 2012
by Mike Levy  

X-Fusion Prototype Details

• Single crown, inverted design
• Travel: 160mm
• Air sprung
• Uses twin-tube HLR damper from Vengeance
• External adjustments: rebound, separate high and low compression, air pressure
• Weight: 4.3lbs (claimed, prototype)
• Availability: TBA
• MSRP: TBA

X-Fusion's stock has been on the rise ever since riders began to catch on to the impressive performance of their HLR damper-equipped Vengeance fork. Admittedly the underdogs in the suspension biz, the Vengeance equalled, if not surpassed, the performance of more expensive offerings from the competition. While the Vengeance's travel has been upped to 170mm, X-Fusion has also been working on another project that slots in the same realm: a 160mm travel inverted fork for the aggressive all-mountain crowd.

Anyone who has ridden an inverted single crown (remember the single crown Shiver or Dorado?) knows while there are advantages to the upside down layout, torsional flex is simply too much of an issue to make the chassis a contender. Having said that, talking to X-Fusion at Eurobike gave us the impression that they are quite confident in the prototype's stiffness, with them also admitting that there is some internal trickery going on within the tubes that greatly ups the fork's rigidity, although they wouldn't go into detail.

Time to speculate? Of course. The fork employs a standard sized 20mm thru-axle, as well as somewhat average diameter stanchion tubes, and we're betting that it also uses a typical dual
bushing layout inside of each leg. The answer, we think, lies in an interlocking shape on the upper portion of the stanchions (hidden from view within the upper tubes) that mates with the upper tubes. This arrangement would greatly reducing twisting under torsional loads, allowing X-Fusion to build an inverted fork that approaches the torsional stiffness of their burly Vengeance, but without the added weight that would usually be required to meet that goal. X-Fusion was mum on the topic, and we're simply making an educated guess, but this design would be one of the few ways of building a 4.3lb (claimed) inverted, single crown fork that is stiff enough for aggressive riders. There would obviously be challenges when it comes to having the shaped sections slide smoothly within the upper tubes, but we're betting that X-Fusion has come up with a remedy for this.

Why would X-Fusion, among others, pursue an inverted design, especially when it presents such a design challenge? It boils down to less unsprung weight (mass not supported by the suspension) that allows the suspension to react quicker to impacts, with another plus being that the fork's lubrication oil is likely to spend more time around the seals and bushings, thereby keeping the fork running smooth.

X-Fusion Inverted prototype

The prototype fork is fitted with X-Fusion's HLR damper, the very same unit that has proven itself within their high-end Vengeance offerings. External adjustments include separate dials for both high and low-speed compression, as well as a rebound adjuster at the top of the fork. The twin-tube HLR damper has shown to be among the best out there, leaving X-Fusion with the task of designing a new inverted chassis and dropping the HLR unit into it. When will we see a production version of the inverted fork? Will it actually make production? We don't have the answers to either of those questions, but we're crossing our fingers that we get to try it on the trail at some point soon.


www.xfusionshox.com

Author Info:
mikelevy avatar

Member since Oct 18, 2005
2,032 articles

243 Comments
  • 164 19
 no no no, x fusion, dont dick around with inverted forks, and give me a 200mm DH fork!
  • 89 17
 Yeh! A 200mm Inverted DH fork!
  • 31 107
flag TouchMeslowly (Aug 29, 2012 at 11:04) (Below Threshold)
 No
  • 60 3
 @TouchMeslowly you seem to be posting negative comments on everything...
  • 10 4
 200mm USD with single crown?
  • 16 0
 Damn it! So close X-fusion! When we said inverted we meant an inverted DH fork! But, I've always loved the look of inverted SC's...I'll be interested to see what kind of flex it has. I rode the old marzocchi Shiver SC and that thing was a wet noodle in corners, maybe this will be better.
  • 21 1
 who cares if it is inverted or not just make a 200mm DH fork
  • 10 1
 Anyone who has spent time riding a single crown Shiver knows this is a fantastic idea. They were a little flexy but not noticed much on trail - the damping was unmatched.
  • 4 1
 Old Marz dampening in general couldn't be touched. Still to this day my old Super T's were soooo plush compared to some of the forks. Hopefully I'll get to try a 2013 soon to compare.
  • 11 0
 I think Xfusion's probably following the money. More people riding Enduro than DH, so they're following the $$$. Still, they must be on to something if they thought about spending development time on a fork like this...
  • 3 1
 I agree krash. I had a set of SuperT's as well. 2001's. They were awesome. This is why we need more competition in the market. Better forks are possible. I have ridden them. That being said, I have a 2011 888 and It's really great. My next trail fork will be a Marzo, so long as they keep up the good work. With the recent developments over there we will have to wait and see.
  • 16 2
 220mm DH fork!? Possibly!?
  • 5 1
 ^I AGREE. I would love to have a fork with more than 8 inches of travel. I know I'm weird and most people wouldn't, but I love love love travel and would buy a 220-250mm fork very quickly. I've owned several forks over 8 inches and they always ride better for me, especially since the rear travel on my main bike (Karpiel Disco Volante) is 200-250mm.
  • 6 89
flag TouchMeslowly (Aug 29, 2012 at 12:39) (Below Threshold)
 why would you ever by a x-fusion. im sticking with rockshox and or fox, simply the correct choice
  • 15 0
 your probably saying this and havnt even ridden a x-fusion on a trail. they are great forks.
  • 6 0
 You can't discount XFusion purely cos they're newer and less known than Fox or RS, most of the time their products are as good, if not better than the competition, and are generally cheaper!
  • 4 0
 i completely agree.
  • 6 0
 @touchmeslowly, you obviously have never tried x-fusion products recently. The vengeance is one of the best forks on the market and the rest of their products feel as good as any other company, some better. and yes, i've owned everything. look at my pics. It's right on par with fox. I would put them ahead of rockshox and marzocchi for 160mm forks. I like x-fusion bc their CS is some of the best in the industry. If you have issues, they will talk to you for a while and make things right. That's not something that a ton of companies can say. I'd be willing to try the fork. It may not be amazing, but that's why you have to try it.
  • 3 0
 i LOVED my shiver, inverted forks are soooo plush. i agree that i would like a dh fork from them but do not stifle the progress of any fork development @ Wattersto!!
  • 2 2
 @nmpearson, my "CS" experiences with X-Fusion were much different than yours, sadly. 2 different products, number of different problems, and nothing truly resolved. I would agree with touchmeslowly.
  • 2 5
 Well the Vengeance R fork is rubbish. You have to get the HLR versions of shocks/forks to get more than decent Smile
  • 5 0
 TouchMeslowly you never realized that most of the Fox products are made in the X-Fusion factory
  • 3 1
 @krash - the old bombers were a lot plusher than anything we had seen before but they were pretty badly underdamped until about 2006 when they put in the rc2x damper. Good for slow tech riding.

If these are as stiff as X-fusion claims, they could be onto something. They have tough competition from the 36 Float though.
  • 4 0
 This design also offers the possibility to replace only one stanchion in case of damage, versus replacing the whole Stanchions-crown-steerer assembly on normal single crown forks.
  • 1 0
 Ya I hear ya as I owned a set of Bomber's with their newer damper. I didn't mention it in the comments but those older forks were aimed for the type of riding during the FR era, so it makes sense that they were good for the slow techy stuff and underdamped. Never really saw Bender or Simmons hauling ass 60 mph off a feature...it was more roll up to it and hit it, which is where the nice plush feeling of the Bomber came into play.
  • 3 6
 if its not a carbon frame its an inverted fork :/
  • 2 1
 Have to question the strength of an inverted fork without a bridge at any point... Even of it is only a 160
  • 3 3
 a 220mm fork would be awesome
  • 1 3
 as amazingly awesome a 220mm upside down fork would be, its just without the brace there is no way at this point in time to make it both stong enough and light enough to put on a bike. and going above 200mm on a regular fork design would mean bike manufacturers will have to radically redesign their bikes to keep right geometry... which would cost them lots of money Frown 4
  • 1 1
 there would be no radical re design, the majority of folks out there that know whats up are running their forks atleast an additional 20mm above min required height. Theres your space for 20mm extra travel, frame geo doesnt need to change. not a bad idea, especially on something like a v10.
  • 1 0
 " Have to question the strength of an inverted fork without a bridge at any point... Even of it is only a 160"


Well considering inverted forks were ridden the hell out of in the original Rampage comps, and many people ride gnar daily on them.
Questions? www.pinkbike.com/video/14844

I can guarantee 99% of pinkbike doesn't go big. Sure these guys aren't "pro" big, but they still hack it more than the majority.
Speaks for it's self. USD forks are epically strong.
  • 34 1
 Its awesome to see a company like X-Fusion really pushing the big boys at performance against price, and if they can push to make this work then even better. Keep it up!
  • 4 0
 Word
  • 10 0
 Yep yep. And guess who wins? We do, cheaper better forks for all! Big Grin
  • 1 0
 @baca262 Or, even better, wait until marzocchi brings the shiver back Big Grin
  • 13 1
 OMG lol, maybe when other forks like this come out , normal forks will go cheaper!
  • 8 1
 This will be my next fork. I have preferred the inverted design for many years. People complain about the "supposed" flex, but on the tail, the inverted design tracks and corners better. I was hoping for a re release of the SC Dorado, but this will do. All the haters have never run an inverted fork to learn how to use their advantages to their benefit. You will lose the hold the wheel in a bike rack and turn the bars contest though.
  • 5 0
 Ditto, insta-buy for me.
  • 1 0
 i only hope they will come out with an inverted dh fork before i get a 888cr.
  • 2 0
 It likely uses a multi-sided stanchion that's running inside the outers on needle/roller bearings, the same way Lefty forks work (and they too are inverted).
  • 1 0
 doubt it, then what's the point of having round stanchions in the first place? blocking the rotation was the motivation for roller bearings in the lefty, the stiffness was a welcome side effect. i think they rearranged bushings to one on the top of the stanchion sliding on the inside of the upper tube and one just above the seals like in moto forks but i may very well be wrong.
  • 2 0
 Round stanchions and sliders are easier to seal which is why the Lefty runs a full piece fork boot instead. Its no different than the new Thomson dropper post, which has already been described as having such an internal arrangement to keep it from rotating, yet relies on conventional round external parts where its moving over the seals.
  • 2 0
 deeeight, this time, I am agreeing with you - i usually refrain from entering into conversations/comments where you post because your mtb eknowledge and intelligence, no matter how correct/referenced/trail tested, often come across as douchery. :p BUT, you are probably spot on with the stiffness/design aspect. Who is making lefty internals nowadays?
  • 1 0
 I believe they switched from Fox to Rockshox because it improved the quality control, features and dropped the price.
  • 1 0
 If they use needle bearings and a square stansion inside the fork leg ( I think thats what you guys are getting at) what happens when the round part of the stansion meets the bearings?
  • 1 0
 the bearings in the pic baca262 posted would move up the leg as the fork traveled, they wouldn't ever hit the round part of station, if they were used with square ones. alternately, they could just not start the bearings until they hit the max travel in the leg. (the bearings don't start until square part of the stantion starts, at full compression.)
  • 5 0
 Look how big the uppers are where they go into the crown. Probably on the order of, oh, 40mm or so? The rigidity comes from 2 places that they have obviously done a very good job of and hopefully we see in production: 1) What appears to be a forged billet crown with huge clamping area diameter on the uppers and 2) a totally badass axle system. Take a good look at that axle/lower bracket system.

Build it, I'll sell my 2011 Float 36 RLC.

Are you listening FOX? and maybe XFusion will sell me internal parts so I can work on it myself...
  • 1 0
 If they release one, I think I'll have to think real hard to pick one between one of these and a BOS deville ... Might get one of these and put some custom damper to get it level with a BOS ^^
  • 3 0
 inverted forks are bad ass and super plush with bottomless travel! Custom armor is a must but that gives us who like to tinker some self satisfaction too. Im running a Stratos S8 203mm of super plush travel and I must say it would be really hard for me to go back to a regular run of the mill dual crown. Inverted is the way of the future!!!
  • 1 0
 "bottomless travel" ...? Blank Stare
  • 1 0
 come on really?!?!?!? If you dont know what im talking about go get and inverted fork see for yourself!!!
  • 3 0
 Since the demise of Maverick Suspension and Bicycles, some 'inverted fork' fans now have something to look forward to. Not sure if this proposed fork by X-fusion will be as simple as the old Duc32 and SC32. Could be interesting!
  • 2 1
 I have a DUC32 on my MojoSL. Awesome combination. Its also 650b.
  • 1 0
 i heard about that, so sad when a company dies 8'(
  • 2 0
 I'm all over it. Why do all good motorbikes use USD forks? Look at a motorbike, and if it has RWU forks it is either old or shit. No one has raced in any world championship on RWU forks since about 1989. They may be heavier but they look better, work better and are stiffer, not flexier. Having that bigger diameter tube going into the crown or crowns increases stiffness. That's why they are used on motorcycles, as well as the unsprung weight reduction.

I'm more of a motorbike guy and when I got back into pushbikes a couple of years ago I was confused by all this talk of USD forks being flexy. I guess maybe for a given weight they could be, but when ultimate stiffness is concerned a RWU design cannot compete with an USD layout.

In motorsport, performance is more important than weight. I think it's the same with DH. The big boys should all be doing USD. So what if it weighs 500g more? If it works better and looks better people will still buy it.
  • 6 2
 I would definitely be interested in this fork, especially if it is easily lowered to 100mm or lower for DJ/street/4X use.
  • 2 1
 Do you really think something that might not be stiff enough for trail use will take some street rotations?
  • 3 2
 I believe it would be plenty stiff for trail use. This is not the first time that an inverted trail fork has been made.
  • 2 3
 It isn't and I've never ridden one. But torsional flex was the buzzword with those things, as stated explicitly in the article. Fox canned the inverted 40 for the same reason. I'm not exactly confident it could replace my Argyle.
  • 6 1
 the small bump absorption of a inverted work is well worth the minor torsional flex penalty. which I might add unless you are a legitimate above average rider/racer you will never have to worry about flex, my 05 Shiver DC has some flex yes but I am at best an average rider and most of the flex is due to my size (6'3 220 pounds). most of the people on here claiming to have an opinion have never ridden or have owned a inverted fork. I have ridden and owned a 2011 boxxer and 888 evo and the plush feeling my shiver cannot be touched, and that is no bull.
  • 2 1
 Sure, I'm not saying the fork is a bad idea. But why on earth would small bump sensitivity be worth sacrificing strength on a street bike?

Street forks are pumped so stiff that they only move under impact, it isn't going to make your commute to the skatepark easier. DJ, maybe.

The average rider could get away with it. 4X, yeah why not. But a Fox 32 doesn't last a month under a rough street rider. Is this fork 32 or 36mm stanchioned? If it's 32mm it will snap like a noodle.
  • 2 0
 With 160mm of travel I doubt it's got 32mm stanchions. My guess would be 36mm.
  • 1 0
 Yeah I was thinking the same. Doesn't make it any less of a logical decision.
  • 1 0
 *Any more logical.
  • 1 1
 Just saying that a 160mm 36mm stanchion'd fork would be popular for a lot of different disciplines if it was able to be lowered to basically any travel setting.
  • 2 0
 And I agree, but not for street. To be honest I can't see many people running it for DJ either. Those points are what I took issue with.
  • 2 0
 A 34mm inverted fork will feel similar to a 36mm conventional. The Dorado has 36mm stanchions, and the conventional designs use 38-40mm. Feel on the trail is about the same.
  • 2 0
 my apology MTB KING I skipped the starting message about lowering it for a street/4x/djing. for short travel hard hit applications, no a inverted fork would not make sense for those.
  • 1 0
 Thank you.
  • 2 1
 i bet it foot jams amazing... this would not work for street.
  • 1 0
 *Legjam
  • 2 1
 would be a body jam for anyone less that 6ft lol
  • 1 0
 If they have found a way to remove the twist, it might be the reason they haven't released their 200mm fork yet in order to build an inverted chassis instead. If they have, it could be a market changer. I am thinking we will see a new Shiver DC this year or next too. And yes I'm sure it will come with stantion guards. They are just off to show the full chassis. You can see the bolt holes for the guard on the side if you look closely.
  • 1 0
 I'm very curious about a new shiver, with all the problems at big M this year. Hopefully so, and hopefully it lives up to pre-Teneco standard.
  • 2 0
 DVO hinted a USD dual crown is a real possibility. DVO is where the Marz suspension people went to.
  • 1 0
 If they don't (which I hope they will) the guys at DVO likely will.
  • 1 0
 I'm sure DVO will, but I'm skeptical that their first products will be anything but typical forks, as much as i like USD, i wouldn't release it as my first product from brand new company. Better business to release something more people are comfortable with first, then start getting into the more unusual stuff. Many of the responses here show how many people feel about the whole concept.
  • 2 0
 I agree with it being difficult to market unusual at first but, I think if they could prove it worked, it would be worth not having to develop two products just to satisfy naysayers. And besides, there are people who would buy it just because its diff as well, if its reasonably priced. These people would provide the base of positive reviews to push forward.
  • 1 0
 True, I imagine how much cash reserves you have to survive it it doesn't turn out well is a big deciding factor. However, I would suspect that they aren't going to release only a USD fork: even motocross, where USD is huge, still has normal forks available.
  • 2 0
 Groghunter, I haven't seen a conventional fork in MX for years, probably at least 10 now.
  • 1 0
 wheres the news on DVO? I heard they had a van at cworx but no product yet, if theres gonna be an inverted fork war there should be a proper shiver 2.0 boys
  • 1 0
 No news, just uninformed guessing that Marz or DVO could release a USD platform.
  • 1 0
 Willie1: www.motorcycle-superstore.com/2/10/217/192/1/0/0/DEPTPCLASS/Dirt-Bike-Motocross-Forks-Suspension-Parts.aspx

Not saying people are buying them, because who would, but you can still get them.

Even if they weren't though, it would still be a pretty big risk coming out in the bike world with only inverted designs.

AWESOME, but a risk.
  • 1 0
 in this case there is a real need for a new axle standard (unfortunately this means a new rotor standard too) but will anyone make a new standard? hell no. the only valid reason for new standard is to make people buy new products.
  • 1 0
 i'd like to try that, but i would be worried about these dials on the bottom... on my fox 36 it's always a challenge to open the protection-cap on the bottom of the fork to adjust the hi/lo-compression, i don't want to imagine those knobs after a season of riding.
  • 1 0
 I had a pair of single crown shivers on my old bullit, they were silky smooth. Plus,they looked the dogs danglies. Not once did i damage the lowers, they had stanchion covers on them. Only issue i had was a little flex and i went through bearings in my hub at an alarming rate, disc side only. These look really nice indeed, only time will tell if they are as good as they look..
  • 1 0
 Seems like the potential to f*ck up ur stanchions increases quite a bit? I mean shit happens regardless of whether you're a hack or not. I guess some custom armor would be in order...but just not sure what I think yet. Am I missing something? I get the pro's but what about the cons?
  • 1 0
 Mike, you say "it boils down to less unsprung weight" as if this is a fact for MTB forks. I would really like to see some proof of this.

Magnesium cast lowers are so light that there would be little to no difference in performance, especially when you add the weight of the wheel and, especially, a DH tyre. I was going to write an article on this subject and, well, riding got in the road but what contact I did have from a fork manufacturer put the advantage down to oil on the seals, not unsprung weight. I can forward you that email if you like.

This "less unsprung weight" is passed around in this article as if it is a proven fact, but I am yet to see the proof.
  • 1 0
 can be,up side down fork with just one axel,stiffer then commonly used design,don't think so,i know unsprung mass,but you got two places of support in normal one...still think it's better? not to mention how many nicks you got on traditional one (lowers) .
  • 1 0
 Looks SEXY Salute IMHO if this guy is at a good price point id love to put it on my xc bike,perfect design for my hard trail.. id love to see a 220 mm dual crown invert for racing DH&big mountain stuff.Looks sick iv never had an X fusion though....very cool tup keep it coming inverted X Fusion!! ?? (wait does it not have stanchion covers) ??
  • 1 0
 There is a reason all MX forks are inverted. Actually many reasons. They are just better. I'm not sure what kind of a clueless tech weiner you gotta be to think that an inverted fork will suffer from some sort of so called "torsional flex" any more than a crappy conventional would. The wimpy little arches on conventional forks do f*ck all really. As long as you've got fat tubes (slider/stanchions/axle) and a robust crown, then you're fine. If you're still complaining, then you're a whiner who doesn't know how to ride anyway. I broke one side of my 66 arch off years ago & rather than waste money on potentially another poorly designed fork, I just broke the other side off & I've been rockin' ever since. The fork works just as well as it did before except now I have more mud clearance & less unsprung weight. It's also easier to disassemble. It's a 7" travel conventional fork, with 35mm stanchions, 20mm axle & no arch. When you flip it upside down & put the larger tubes in the crown you gain so much more strength & stiffness. When you double the diameter of a tube you quadruple its rigidity with the same wall thickness. Inverted forks also offer more bushing overlap meaning smoother operation, greater stiffness & longer life. They also just look better but beauty is in the eye of the beholder so w/e. If Dorado's & Shiver's had problems then it was because they were designed wrong, not because there's anything inferior about the inverted model. I was planning to buy an X-Fusion to replace the last piece of buttload that I'll ever buy from Marzocchi & now I want one even more. The only things I'm not liking about this invert is the lack of guards on the lowers, but I'm sure they'll change that, & the profile on the bottom of the crown around the legs. It should just be straight so that it offers as much support as possible.
  • 4 0
 marzocchi shiver sc & marzocchi rac
  • 7 4
 looks awesome but is there that much of a difference between this and a vengeance?
  • 51 0
 Yes, This one's upside down.
  • 3 1
 They look pretty cool! But to be honest aren't forks ok just the way they are now? What's sort of advatages are we looking at? Because I can't see any..
  • 11 0
 The oil constantly sits on the top of the stanchions so they are better lubricated and smoother and there are no heavy lowers so the responsiveness on the fork increases.
  • 7 0
 Lower unsprung weight.
  • 5 0
 Why would X-Fusion, among others, pursue an inverted design, especially when it presents such a design challenge? It boils down to less unsprung weight (mass not supported by the suspension) that allows the suspension to react quicker to impacts, with another plus being that the fork's lubrication oil is likely to spend more time around the seals and bushings, thereby keeping the fork running smooth.
  • 3 0
 yeh and I must say 4.3lbs for a 160mm fork is pretty impressive.
  • 1 0
 Ohhh cheers mountainbart! Surely though if they were better other brands would make all there forks that way? From the Derodos I've ridden they seemed very flexible! Compared to other 200mm forks
  • 1 0
 I'm guessing flex won't be such an issue on a trail fork, and I'm not sure, my guess is that they were put off by the flex and the whole marketing side to it and people not buying them for that reason, the vulnerability of the stanchions would also be a negative factor.
  • 6 0
 The moto world switched to the inverted design to get better cornering and tracking at less weight than they could with a conventional design. Current inverted forks are averaging about 46-48mm stanchions. Traditional designs lost out when the stanchions had to go bigger than 50mm to try to equal the tracking of the inverted design. There were a lot of engineering articles out at the time of the transition, that showed the most flex happened at the triple clamp. Inverted designs were more rigid there giving better tracking and steering precision. Second flex area is the axle, which Hexloc and 24mm axles addressed. The Lefty has its own way to deal with this which is really effective. The break arch was tried on Motos but it didn't solve the triple lamp flex.

You guys all drank the marketing koolaid propaganda that the MTB suspension world promoted to keep R&D costs down. I have ridden so many different forks since I started riding in 1982 (not a typo) and cannot understand the sheep mentality in believing the crap. Fox's latest leaked prototype was just more of the same. How many Dorado owners complain they have poor tracking on their Dorados? None. They just smile when people clamp the wheel and turn the bars claiming excessive flex.
  • 1 0
 Yea, look at the comparable forks, as well:
Shiver DC: 1lb heavier than a Fox 40,
white brothers: 2 lb's heavier,
Dorado: had to use carbon fiber uppers to get it to a decent weight,
Foes F-1 XTD: I couldn't find a weight, but I believe it's heavier too.

It's worth the extra weight, in my mind: been riding a shiver for almost a decade. But lots of people look at that number to exclusion of all else.

As for flex, the one's I have expienrience with could all have been made stiffer with some design tweaks that were obvious to even me, so I'm not surprised that they might be able to make this work.
  • 2 0
 Current Dorado, 1lbs lighter than a 40, better damping, better tracking. Best performing fork on the market.
  • 1 0
 I still find Manitou suspect, but completely am aware that my experience with them is from back in the day. However, last i checked, the Dorado is priced like you would expect for a fork with that much CF on it. Like, comparable with the Foes F-1 XTD price.
  • 1 0
 The current Dorado is aluminum, and priced the same as the other companies top line DH forks.
  • 1 0
 news to me, thanks for the info. I'd still want to ride one though: the old school dorado i rode was so awful as be almost non-functional.
  • 1 0
 the Dorado seems to dominate the bc racing scene thats for sure. I am also looking forward to what DVO produces now that marz seems to be going tits up, maybe thats where the new shiver will come from? they will need a non-round axel though like Manitou hexaxle or whatever Xfusion is calling theirs on the delta it looks smart though and no manitou petent infringement. they better patent that quick eh.
  • 5 1
 USD Single crowns are sexy! We need more of them.. that was all...
  • 3 0
 think about lefty... inverted, one legged, and the stiffest. this has two legs!
  • 1 0
 tell that to g123
  • 2 0
 Ha.. well I guess my comment wasn't liked by someone... *DELETED!*

Again - 2001 Shiver SC was inverted, had 4" travel and a lockout > Ten. Years. Ago.

And keep your bike stored upside-down kids. Keeps the seals lubed and slickery.
  • 1 0
 The Shiver SC actually had 120mm of travel, roughly 4.7 inches.
  • 1 0
 I stand corrected - 4.7" travel. I was going by memory. I should get points for having one collecting dust in my garage though...

The point is still, by removing the middle arch of a standard single crown fork, you lose considerably more torsional stiffness than any "internal trickery" can make up for. I would have to actually see big weight savings in unsprung weight to even think about going the inverted route. Granted, I haven't ridden anything USD since the Shiver days... but I did own and ride both the single and double crown Shivers for long enough to know that they were ok, but yes.. noticeably flexy in hard corners and rock gardens.
  • 1 0
 my fork especially doesnt like upside down storage, if i leave it for about 10 minutes, then my fork is f*cking fast on rebound and knocking still the oil starts circulating again after maybe 20 pushes with the hard knocking (888 rc3 wc)
  • 1 0
 thats my 888 in one day of no riding so it cant matter that much
  • 1 0
 storing upside down is also an excellent way to move air into your brake lines and caliper. so don't.
  • 1 0
 with a proper bleed you shouldnt have that problem... but then again ive tryed the old elixirs before and tilting the bike up to put it on the lift just destroyed your bleed
  • 1 0
 yup, and in my experience, even brakes that don't have that problem, will if the lever get's squeezed when they're upside down, and if you do it all the time, it's gonna get knocked sooner or later.
  • 1 0
 Wow. Properly bled brakes really shouldn't have that problem. Really, the only way you can have air problems with your brakes is if they aren't fully bled. If you can't get your brakes to be air-free, then it's not being done right. If your fork has issues with being upside-side, I would also say that your cartridge may be low on fork oil. Cavitation after the fluid drains to the top of the cartridge is a symptom. Open bath is obviously a diffrerent story, but should be normal almost immediately after flipping upright and riding. These are my experiences over enough years, and the recommendation from more than one mechanic. If it doesn't work for you, then don't do it. If you like to have well lubricated seals and bushings, and have properly bled brakes then maybe give it a try.
  • 3 0
 Rubbish. you cannot get 100% of the air out of DOT fluid: It's hygroscopic nature means that it will get water in it to some degree, which turns to steam as soon as your fluid gets above 100C. Secondly, having bled brakes for years, you pull as much air as you can out of the fluid, but there's always some dissolved that you don't get. this is one of the purposes of the master cylinder reservoir: it's a place for air to collect where it can stay at the top of the system, preventing it from re-entering the hydraulic circuit.

Because you've had good enough bleeds, and good enough seals in your brakes that it didn't affect you doesn't mean that storing your bike in a manner that can leak air into the circuit is smart thing to do. Fork seals leak oil and make a slight mess if they dry out, air in your brake lines can cause your brakes to fade or fail at a critical time. your choice.

Or get an inverted fork.
  • 1 0
 Grog, I'm happy to agree to disagree, it's not rubbish at all. Yes, dot fluid is hygroscopic but I'm sure knowing that, you also know that service interval bleeds are recommended to change your brake fluid before enough water contaminates the system to cause an issue. But this is minutiae of tech, I see your points but don't entirely agree which is fine. I won't assume to know your background, and please don't underestimate mine.

The main point was about the loss of torsional rigidity from removing the middle arch of a conventional fork. I'd be more than happy to demo a U/D fork, and would be happy if it would change my mind. But until I see enough feedback saying that it is truly different than what has been hashed out in the past, I'll hold off on saying carte blanche that it 'will be my next fork' because it looks sexy. Having seen enough BS gear come and go, I want shit that works at least as well as claimed and lasts reasonably well with proper service.
  • 1 0
 I didn't underestimate anything: You are simply giving out advice that could cause a persons brakes to fail at a critical time, in order to keep their seals lubed. If you can't see why that's a bad thing to do, that's your affair.
  • 1 1
 I'll be honest. I don't care what it weighs, I don't care what it costs, I don't even care if it's all the reliable. I want that fork. I REALLY want that fork.
It's giving me nostalgia for my old Shivers... ahhh. Just need some stanchion guards, maybe the old Shiver ones would fit?
  • 2 0
 Flex is not an issue , but one question how long will those stanchions will last against rocks and such? one scratch and all the lubrication benefits are GONE!
  • 1 0
 I guess thats why Moto forks are replaced every time the rider rides. Wait, they aren't and they deal with 50+HP bikes throwing rocks at them. Maybe it isn't really a problem.
  • 1 0
 Aibek - I was thinking the same. - Willie1 - most moto tracks these days are very free of rocks - mostly groomed dirt, vs natural terrain with rocks everywhere. Where I ride, there are rocks and bedrock everywhere. Most MTB forks usually scratch up on the lowers.
  • 1 0
 When is the last time you raced MX? There are rocks everywhere. I am not talking about SX here. I have a broken right knuckle from roost from a Yamaha 450 from a few years back.
  • 1 0
 It's been a long while - but my brother is still doing it - I see you're up in Canada - I think American tracks are much more watered down. Sure there's some rocks about, but look at the DH courses and the AM enduro stuff - that's just crazy.
  • 2 0
 Marzocchi had the shiver's ages ago, they make one of the best moto forks out there! why did they dump it (the shiver)? they already have the "know how" of making inverted mtb forks!, sure it looks cool , but that's all its about (FOR MTB).
motos have plastic guards on the stanchions, on a mtb because there is no engine sound , those guards will flap around and make some irritating sounds!.

hah made me laugh on that yz450 you should try the roost from a kx500R (not a fun being behind of, but kickass being on one!), other than two wheels, handlebars and a chain moto's and mtb have nothing in common, so please do not compare them!.
  • 1 0
 what about moto enduro where they ride through the same terrain as a DH or AM trail and alot of the thime the tracks are worse
  • 1 0
 what about moto enduro where they ride through the same terrain as a DH or AM trail and a lot of the time the tracks are worse
  • 1 0
 I have been roosted by 500s. I raced open class when there was such a thing. I had one of the 1985 CR500s. That thing had such a hit it was almost unrideable. The Husky 500 was much easier to ride, and was 6 speed, so it worked really well off road as well. It was much more versatile. The inverted fork and disc fixed the only real flaw that bike had, which was the drum front brake. I still have my 510 Husky 4 stroke from 1983. It now has the USD fork on it.
  • 1 0
 Already like the idea of the upcoming X-Fusion 160mm Slant. Didn't expect to see this inverted fork prototype. Ok, now it's DVO's turn to show us what they have coming for 2013.
  • 2 0
 Hahaha time to sit back and listen to all the idiots talk about how "flexy" it is.....mtbrs dont know f*ck all about suspension.....
  • 1 0
 Generally USD forks have pretty stiff protectors bolted on to the fronts of the fork ends. All the scratches on my forks are from hitting other bikes in the back of cars etc... USD or not, that's still going to happen.
  • 1 0
 Forks are made today the was they are for a reason. Lowers are supported to take damage, stantions should be left as clean and un-damaged as possible. I guess it's just a sketch-fusion thing ..
  • 1 0
 Isnt the main problem with inverted forks the fact that the stantions are lower to the ground and get scratched easily from trail debris?
  • 2 0
 Oh wow, I am so surpised! I would never have thought X-Fusion would try this
  • 3 1
 invert forks = less unsprung weight, which in turn will make you bike ride better...
  • 2 0
 theory, pal, in real dh life not an issue. Scratched, dented stanchion ruin your day.
  • 3 0
 stanchion guards? you can scratch regular forks by crashing in rocks and thats more likely to get scratched then inverted in that situation
  • 1 0
 motos went back and forth with inverted then not for years. Dont think any moto company has had a fork that wasnt inverted for the last 15yrs. if its strong enough for a 200lb plus moto why not for a mtb.
  • 1 0
 eh whenever i crash it seems my lowers get fcked up not the stanchions..
  • 1 0
 your lowers dont have guards on them tho
  • 3 0
 Ahhh I want these forks so badly! SHUT UP AND TAKE MY MONEY!
  • 1 0
 Once you've seen the state some peoples lowers on their forks get into, I just don't see how inverted forks could be a good idea :/
  • 2 0
 You put guards on them just like they do on MX bikes.
  • 2 0
 so now that paul turner works at x-fusion, they're bringing back the maverick forks? upside down dual crown next?
  • 1 0
 WANT WANT WANT WANT
  • 1 0
 Railgunner. DVO will show prototypes by year end. Everyone should save their hard earned money until then. Trust me when I tell you.
  • 1 0
 Single crown, inverted? Ya, that'll work well. What the hell are they thinking? Single crown inverted forks are legendarily bad.
  • 1 0
 Just a question. Wouldn't the stations get bashed around on the rocks and stuff on a downhill track if it was the other way around?
  • 1 0
 Looks are as important as performance to most people, though most won't admit it. USD looks a lot better than RWU, and that is why they will sell.
  • 2 1
 Hence why motocross bikes adopted inverted forks design nearly two decades ago...!
  • 1 0
 no one is doubting inverted forks are stiffer, but with motocross, its a different story. the forces put on a motocross bike during racing, is much more than the forces that are put on a mountain bike, even a dh rig. fox came out with a dual crown prototype once, and they said it made it stiffer, but was...i dont know, overkill.
  • 2 1
 not stiffer torsionally.... but you gotta be a lard ass or just super fast to notice flex anyways
  • 3 0
 when motos changed to inverted it was a total game changer once they got it figured out. i had both on new motos back in the day & it was a huge leap in handling, cornering, just plain everything...
  • 1 0
 Helm72, I had the exact same experience. My first inverted fork was a WP which was retrofitted on to a Husky 500 in the late 80s. I had the last of the conventional forks as well, the Suzuki which had 50mm Showa stanchions IIRC. The 50mm fork wasn't as rigid as the old WP fork LOL. The only downside with the early inverted forks was they were worse on small bumps when they flexed at the bushings. Later designs were a lot better, when they used better materials in the stanchions. Moto forks use chromoly stanchions which flexed more than the aluminum ones MTBs used.
  • 1 2
 I agree that the stanchions appear to be exposed to excessive wear/damage from rocks etc. I for one would be absolutely pissed if I bought these and then gouged a stanchion on a rock early in their life...
  • 4 0
 Most inverted forks come with removable stanchion guards.
  • 3 0
 I'm sure they will get covers like every other inverted fork did or has. It's just a proto and uncovered for show.
  • 1 0
 i like it but ive always wanted to run upside down forks on my dj??? possibley it ^
  • 3 0
 Like
  • 4 0
 finally some evolution our way !!!
  • 1 0
 Yeah bro...inverted forks are very cool and super plush...wouldn't mind trying this baby...
  • 2 0
 damn looks sick good job xfusion
  • 3 0
 Yesssssssss !!!
  • 2 0
 I really like them, and WANT them NOW
  • 1 0
 could they have used a bearing system like the one in a lefty? two lefty's would be pretty torsionally stiff...
  • 2 0
 That's some sexy fork... Want one!! Big Grin
  • 2 1
 think about lefty... inverted, one legged, and the stiffest. this has two legs Smile
  • 1 0
 I want one! Beautiful looking fork! I always wanted a shiver...redemption time!
  • 1 0
 170 comments in a few hours. I would say that X Fusion should produce this thing ASAP.
  • 1 0
 I would buy one on spec just for shits and grins. I loved my Zoke RAC BITD.
  • 1 0
 Nice one... X Fusion is on the right track! looking forward to see more stuff coming from these guys!
  • 1 0
 hope they make a 60mm of travel for street use, just sayin :p
  • 2 1
 why would you need a push yet not as stiff street fork? That makes no sense
  • 1 0
 That atomlab fork isn't the best working fork ever but for me street is a bmx exclusive thing. It gives you more possibilities.
  • 1 0
 Just pointing out to the OP that there has already been a 60mm inverted street fork.
  • 3 2
 X-Fusion has yet to unimpressed me with their work.
  • 1 0
 Need carbon stanchion protectors!
  • 1 0
 This is simply awesome! Big Grin
  • 1 0
 im still waiting on DVO 203mm usd dh fork! hurry up guys!
  • 1 0
 theyre probably going to start with an upright first... hopefully theyll offer an upright and an inverted for riders wanting different feel
  • 1 0
 usd is the way forward! fay sexier and better handling of the bumps.
  • 1 0
 personal preference really... some guys like the super rigid feel of 40's and 888's I expect to see guys on boxxers like the inverted forks tho due to the flex
  • 1 0
 Wonder if they will work with 29ers like the dorado?
  • 1 0
 if you can internally limit the travel by 1.5 inches, why not?
  • 1 0
 show me the fork under tr250
  • 1 0
 I MISS MONSTER T'S X-Fusion please make some!!
  • 2 1
 I'm waiting for Samsung to copy the RockShox BoXXer.
  • 1 0
 what advantages do inverted forks have over regular forks?
  • 1 0
 Always wanted to try a SC inverted fork.....
  • 3 3
 Stanchions will get f*cked
  • 1 1
 not really, if they get hit hard enough, the new paper thin lowers would get fucked too, they will also have stanchion guard. and this way there is less chance of scratching them when you lean the bike against something low.
  • 1 1
 It's not necessary to hit hard the stanchions to get them f*cked. Even a scratch will be enough to do that. Also they are more exposed on dirt as inverted.
  • 1 0
 woowowowwoowo
  • 1 2
 When the seals do go, I don't like the idea of fork oil potentially sloshing over my brake rotor and calliper.
  • 1 0
 speaking from expieience: It's not a problem, both because of the fact that the oil keeps the seals in better shape, so they don't fail as bad as normal forks, and because of the direction the oil flows when it leaves the leaky seal. Honestly, most people will never see the problem, though: I've had my shiver DC for almost a decade and it's only needed one set of new seals.
  • 4 0
 So gravity is backwards when you use a traditional fork? The oil doesn't flow down the leg and drip on the rotor?
  • 1 0
 No, but because the oil is dripping down the slick stantion, instead of a painted lower, it tends to collect near the back more. and since the seals tend to be in better shape than a normal fork when you start losing oil, it happens much more gradually, so you don't get much oil leakage unless you leave it way way too long.
  • 2 0
 haha, just realized that you were agreeing with me here, but whatever, we've been all over this thread anyway.
  • 1 1
 My favourite colour is potatoe...
  • 1 1
 have fun keeping those stanchions unscratched
  • 2 3
 What happens in europe stays in europe?
  • 2 1
 What country is Europe in ? Taiwan ?
  • 2 4
 I had a X-fusion fork and the rebound blew up 3 times so we got a RockShox.
  • 2 4
 I am curious myself to what advantage is there being inverted ?
  • 13 1
 Maybe reading the article will help you find the answer you're looking for.
  • 3 1
 Why would X-Fusion, among others, pursue an inverted design, especially when it presents such a design challenge? It boils down to less unsprung weight (mass not supported by the suspension) that allows the suspension to react quicker to impacts, with another plus being that the fork's lubrication oil is likely to spend more time around the seals and bushings, thereby keeping the fork running smooth.
  • 9 0
 Reading articles and comprehension - so out of fashion now
  • 3 0
 less unsprung weight? arent magnesium lowers lighter than alloy stanchions? just my thoughts, I'd buy it just for the libe oil sitting on the seals tho
  • 1 0
 I dont' buy the unsprung weight claim, look at the current dorodo. All of the oil and cartridge sit in the lowers and are unsprung. 200 cc of fork oil along with two stanctions has to weigh more than mag lowers
  • 1 0
 you guys are probably right, i bet my ass that say, new fox 40 lowers are lighter than the dorado stanchions simply because they are magnesium alloy but the lubrication advantage alone outweighs this, inverted fork with a sealed stanchion top could actually work for a long time without overhauls with only 15cc's of oil unlike rs forks since crap doesn't constantly get thrown onto the seals and gravity actually helps keep the oil where it is necessary.
  • 2 0
 Th biggest advantage to an inverted design is the larger area at the crown, with more surface area to be more rigid for the tubes to mount to the crown. This is where the majority of flex happens in a fork.

Unsprung weight is the second advantage. There is less moving weight which allows the wheel to respond to bumps quicker.

There is less overhang at the axle, making hanging up in ruts, clipping rocks or roots, or stumps less likely.

You can use a smaller stanchion with the larger upper with the same rigidity. This results in less stiction from the seals and the bushings. Expensive coatings are not as needed, and SHOULD result in a lower cost in the final product. This also reduces the overall weight of the fork.

Disadvantages:

Slightly more torsional flex. This is only noticeable when trying to push a large object out of the way with the front wheel, (or twisting the fork with the wheel held stationary.) In rock gardens, the inverted design actually tracks better as the wheel can have slight motion under loads that won't be felt by the rider. Tracking is much improved because of this.

Closer tolerances are needed than a traditional design. Since the design is more rigid, loose tolerances result in binding. The fork on the 1992 Suzuki RMs had this problem. KTM 48mm forks in the early 2000s had this problem (from flexy sliders) as well.

Loose seals will weep sooner than a traditional design, as they are bathed in oil. This has been mistaken for shorter seal life, but they wear the same a conventional forks. You are just made aware by the weeping.
  • 3 0
 summary: inverted is good
  • 2 0
 Awesome post.
  • 1 0
 yes, but one thing still puzzles me. How close the stantions are to the ground. If you look at 99% of the riders they always seem to have scratches on the lowers. Now if it was inverted those scratches would be on the stantions
  • 1 0
 Willie1 - USD forks are not as stiff as standard MTB forks mainly due to lack of bracing in the middle of the fork length in form of a crown in lower legs assembly. Then the increased area of contact matters less than the depth of the insert. If you consider two towers, the thin one with deeper foundation will resist wind forces better than the thick one with shallow foundation. What matters most is the arm of the force counter acting the flexing force. There are only two ways of minimizing flex on USD forks and that is nr1 increasing stanchion diameter, so each of them can be stiffer on their own when not given bracing in the middle. However when you look at Fox 40 or RS Totem, and their 40mm stanchions, then that argument goes out of the window. Then nr2, stiffness can be increased by increasing bushing offset, but that can happen only on a double crown fork which offers more room for longer stanchions - because of that fact, the single crown USD fork is nothing more than a style thing. I love the way they look, but there can be no reasoning behind it.

What DVO does with that strange contraption arch at the bottom, is only making the list of features longer - but it cannot stiffen the fork in any significant way. You can place a hemisphere there, and not much will improve, as it is the number of braces and their placing along the length of two rods that contribute to the stiffness of the whole structure. You don't see many electric line masts made of thick rods, with few braces in between - what you see is masts made of thin vertical elements with lots of bracing between them.

The only saviour of USD single crown forks might be the use of composites: a monopiece steerer, crown and upper tubes, all formed in a shape counter acting flex forces. It would look kind of like broad pants in officer shoes. Maybe that is the future, who knows? I'm all for it! But in such traditional form as this X-Fusion, it just can't beat the standard fork with arch.
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