Pivot Cycles has been on a bit of a roll lately, what with the Trail 429, Switchblade, Firebird 29, and Phoenix all receiving healthy doses of positive media and user reviews, plus healthy sales to match. But there’s been one category where the brand has been feeling a little off-the-back in recent years: cross-country. Pivot promises to remedy that now with the release of the new Mach 4 SL, which will replace the long-running Mach 429 SL as the company’s premier XC race bike.
First off, you’ll notice the name: it’s the Mach 4 SL, and not the 429. The original Mach 4 was shod with 26" wheels, and when Pivot switched to a size-specific 29/27.5" setup, that necessitated a badging change. But given how the XC market is now firmly in the 29er camp, Pivot decided to revert to the simpler Mach 4 moniker since wagon wheels are basically a given in that category these days.
Mach 4 SL DetailsWheel size: 29"
Rear wheel travel: 100mm
Front wheel travel: 100-120mm
Head tube angle: 67.5-68.5°
Chainstay length: 431mm
Rear hub spacing: 148mm
Sizes: XS-XL
Colors: Team Blue, Cherry, Stealth
Claimed weight: 20.9 lb / 9.48 kg (World Cup XTR kit, size M)
Frame w/ shock: 4.6 lb / 2.1 kg (size XS)
MSRP: $5,000 - $11,300 USD (complete builds), $3,400 USD (frame and shock only)
www.pivotcycles.com Naturally, the new Mach 4 SL is made of carbon fiber, and also a given is the new bike’s 100mm of rear wheel travel, which continues on with a variant of the dw-link suspension layout that has marked every Pivot full-suspension bike since the inception of the company in 2007. It’s tuned more for pedaling efficiency than longer-travel Pivot models, of course, but it also differs in that the shock is now oriented vertically, tucked tightly in front of the seat tube instead of residing under the top tube as has always been the case with Pivot models.
It’s also very light, it’s compatible with Fox’s fancy Live Valve electronic suspension, it’ll supposedly clear a 2.5"-wide Maxxis Minion out back, and the progressive geometry further blurs the lines between XC and trail with a longer and slacker front end, shorter chainstays, and a steeper seat tube angle.
Pivot will offer the Mach 4 SL as a bare frame for $3,400 USD, or in one of 22 complete build kits, ranging in price from $5,000 to $11,300 USD. Every Mach 4 SL gets the same carbon fiber frame, and at least for now, there’s no aluminum version. But, continuing a most-welcome trend, it’s actually available right now.
Reaffirming the Mach 4 StorylineThe original Mach 4 was a distinct outlier when it was first introduced a dozen years ago. Although its 100mm of rear-wheel travel put it head-to-head with other cross-country bikes of the time, its crazy-stiff welded aluminum frame and more progressive geometry suggested it was meant for much more than just going uphill fast. Subsequent Mach 4(29) models have followed suit, and this latest Mach 4 is no different with geometry that focuses more on high-speed stability than low-speed, point-and-shoot agility.
Even when equipped in World Cup race trim with a 100mm-travel fork, the Mach 4 SL’s 68.5° head tube angle is the same as what Specialized uses on its more trail-oriented Epic Evo, which features a 120mm-travel fork. Nearly all Mach 4 SL complete builds will come with a 120mm-travel fork standard, though, which kicks the front out even more, down to 67.5° (which, somewhat remarkably, is nearly identical to Pivot’s much longer-travel Switchblade).
Chainstay length has also decreased substantially from the Mach 429 SL, from 445mm to a stubby 431mm, while the slightly longer reach dimensions are now borrowed from the current Trail 429. Bottom bracket height is the same as before, though, which is just fine since many already found it to be about as low as it could be without inducing too many pedal strikes. Seat tubes are steeper than before, but not outrageously so — it’s still a pedaling-intensive XC bike, after all.
Shorter riders will be happy to see that Pivot has added a long-overdue extra-small size (without having to switch to 27.5" wheels), and Pivot says the five-size range will accommodate riders from 4’ 10" all the way up to 6’ 7". Clever repackaging of the rear shock — which is now oriented vertically instead of horizontally — means that even the smallest size has room for a large water bottle to fit inside the front triangle, while the XL size can handle two (and yes, there is a second set of mounts).
Standover clearance has improved across the board, too, and the shorter and straighter seat tubes used throughout allow for longer-travel dropped posts. Pivot only specs 150mm-travel posts on the XL size, but my suspicion is that many riders will be able to use those in on other sizes, too, depending on saddle height.
Yup, It's LightAlthough the Mach 4 SL’s geometry paints it more as a trail bike, its showing at the scale is certainly more in keeping with the XC crowd. Claimed frame weight with the stock Fox Float EVOL rear shock is just 2,105g (4.64lb) — over 300g lighter than the latest-generation Mach 429 SL, according to Pivot, and about 700g lighter than a Trail 429. Granted, that Mach 4 SL claimed figure is for an extra-small frame size, and while larger sizes will obviously be heavier, there usually isn’t a huge amount of variation as you move up (and at least Pivot’s claim includes paint, which is surprisingly heavy). Claimed weight for a complete World Cup XTR build — in a medium size — is a paltry 20.9 lb (9.48 kg), without pedals.
A lot of that weight savings comes from the use of higher-stiffness carbon fiber, of course, along with Pivot’s "hollow core internal molding" technology, which uses semi-rigid internal pre-forms inside of the frame instead of the old-school inflatable bladders. However, the tubes themselves are also a fair bit smaller in diameter on the Mach 4 SL than what Pivot uses elsewhere, which cuts down on the amount of material required in the first place. Both the front and rear triangles are more compact than what Pivot has used in the past, too, which cuts down on the amount of material required further still.
Pivot says that additional weight savings came from that vertical shock placement. Since there are no longer any suspension loads being transferred into the top tube, that part could be made lighter — and since the bottom bracket area is already heavily reinforced, no weight had to be added there. In addition, all of the suspension pivot bearings now rest in seats that are molded directly into the frame with no additional aluminum required.
No to DI2, But Yes to Live ValvePivot was one of the first companies to partner with Fox on its fancy Live Valve terrain-sensing electronic suspension system, so it’s no surprise to see that the system will be offered on the Mach 4 SL. Dedicated wiring ports are included for the fork sensor, rear dropout sensor, and controller/battery unit, and the latter is neatly tucked away underneath the top tube.
Upgrading to Live Valve adds an extra $1,900 USD on top of the standard build kits, and adds about 220g (0.5lb). That’s a lot of money, but also a considerable savings over the $3,200 it’d cost to add the system after the fact — plus, the folks at Pivot HQ in Arizona will route all of those wires for you.
Pivot was also one of the first companies to specifically develop mountain bike frames to accommodate Shimano Di2 electronic drivetrains, but — like the Trail 429 that Pivot launched last year — you won’t find any compatible wiring ports or battery storage here. It’s widely expected that Shimano will release the second generation of that fancy electronic drivetrain sooner than later, but given the lack of wiring ports and the anticipated life cycle of this Mach 4 SL, Shimano is either moving to a wireless (or semi-wireless) format, or things are progressing slower than anticipated.
We’ll have to wait and see, but point being that if you’re already dedicated to Di2 and were hoping to use it here, you’ll have to get creative here. And yes, drilling holes will most definitely void the ten-year frame warranty.
Clearances, BB Shells, Routing — And What About SuperBoost?Can’t stand the 157mm-wide SuperBoost Plus hub spacing that Pivot uses on so many of its other bikes? Well, since the Mach 4 SL is only meant to be ridden with 29" wheels, Pivot has built the frame with plain ol’ regular Boost hub spacing instead. That said, Pivot says there’s still enough room between the stays to clear 2.5"-wide Maxxis Minions while running chainrings up to 38T.
Speaking of chainrings, Pivot is following the lead of the Trail 429 in that the Mach 4 SL is built solely for 1x drivetrains, which not only helps in terms of tire and drivetrain clearances, but allows for wider linkages and bearing spacing for a stiffer connection between the front and rear triangles. That 1x-specific layout even takes care of a long-standing criticism of several other Pivot frames: the loop of derailleur housing that dangles below the bottom bracket on the Trail 429 and Switchblade is finally gone, but the ISCG tabs stick around if you’d prefer the added security of a light-duty chain guide.
And speaking of bottom brackets, Pivot is sticking to its guns: the Mach 4 SL uses yet another PF86 press-fit shell. Before you crack out the torches and pitchforks, though, even I have to admit that Pivot seems to do a better job than most in terms of keeping the shell dimensions to proper tolerances. I still don’t like using a hammer when I have to install or remove a bottom bracket, but at least in my experience, press-fit seems to work as it’s supposed to on the Pivot frames I’ve ridden (and owned) over the years.
Cable routing is internal throughout, using the same interchangeable port system found in other recent Pivot frames. Unfortunately, none of the lines are fully guided, but there are at least a fair number of sizable access holes to help fish things through, there’s a lot of flexibility in what can be run where, and the covers also lightly clamp the hoses, housings, and wires to keep rattling at bay.
And finally, from an aesthetic standpoint, let’s all maybe cheer the fact that the Mach 4 SL has been penned more with a ruler than a French curve, and that Pivot is sufficiently confident that it no longer feels the need to put a logo on every frame tube.
First ImpressionsPress launches rarely provide a good opportunity to really get a proper feel for a bike, but Pivot conveniently chose to launch the Mach 4 SL in Fruita, Colorado, on trails that I not only know very well, but also happened to be on just three weeks prior. In typical fashion, Pivot put editors on one of the top-shelf builds, featuring Shimano’s new XTR group, DT Swiss carbon wheels, and the complete Fox Live Valve system.
This was admittedly my first time on Live Valve, but to be perfectly honest, it totally ruined me.
With the system turned on, the suspension is open and active when you want it to be, rigid when you don’t, and utterly settled and composed throughout with no other inputs required. There were also some unexpected benefits, such as incredible support on g-outs, and easier launches where you’d normally have to be more careful with your timing on the lip. You still need to exercise some care when it comes to matching the bump threshold setting to the ground type, but in essence, Live Valve is what the Specialized Epic aspires to be, but without the clunkiness and occasional confusion. Basically, it lets you ride like an idiot, and since that’s my default riding style, it’s a good match for me.
That said, this is still a Pivot cross-country bike with a dw-link rear end, and it works extremely well even with Live Valve turned off. There’s minimal unwanted rear-end movement under power, excellent (albeit somewhat firm) bump control, and very good support throughout the range of travel, just with a slightly busier ride quality and more input required when approaching certain obstacles.
Frame stiffness isn’t quite like what you’d find on a Switchblade — or a burlier trail or enduro bike, in general — but it certainly seems competitive for the category, and balanced from front to rear. And the geometry feels spot-on, at least for the faster trails where we rode: stable and composed at high speed, but nimble enough for rapid-fire turns without requiring too much handlebar wrestling.
For now, my biggest criticisms lie with a couple of spec items.
Pivot includes 29x2.25" Maxxis Aspens front and rear on the more race-oriented World Cup builds, and the 29x2.2" Maxxis Ardent Race for the somewhat more versatile Team variants. They’re light and fast-rolling, no doubt, but the extremely low-profile tread designs aren’t the best for general trail riding.
For the dry-and-dusty trail where I live, I’d like to see something slighter meatier, at least up front. Likewise, all Mach 4 SLs come with 160mm-diameter rotors front and rear, instead of a more useful 180/160mm combo.
Given how capable the Mach 4 SL chassis feels, both of those seem like limiting factors for what otherwise seems like a worthy opponent to the Yeti SB100. Granted, the argument can easily be made that the Mach 4 SL is supposed to be a race bike, and should be equipped as such. However, I’d argue that there are far more people who just want a fast and capable bike than ones who will specifically be buying this to race.
Or, then again, maybe it’s just me riding like an idiot. Either way, stay tuned for a more in-depth review once we’ve got a production sample in hand, and more saddle time on local trails.
A XC bike is their trail bike. Why do you think bikes like the Sniper, Ryve, Signal Peak, Oiz etc... are popular right now?
100-120mm is more than enough for a trail bike- heck a lot of people are riding more bike than they need. But alas this is Pinkbike where everyone is a downhill super star.
He’s not asking for DH tires here - something with a little more tread and a bigger rotor up front would definitely add some versatility to this bike.
Look at the Yeti SB100 - that comes with a 2.3 Minion DHF / Aggressor combo. I know I’d much rather have that then a set of Ardent Race tires. If anything, the fact that these bikes are deserving of meatier tires and a bigger rotor is a testament to how much more well rounded they’ve become compared to the twitchy XC race bikes of the past.
And remember, this is just an initial look at the bike, not a long term review.
I don't think I would see myself ever using the DHF or Aggressor on the SB100. I'd maybe swap them to a burlier bike, but they just don't fit with the go-fast intentions of the SB100, especially for a xc-racer. By the time I'd actually need the grip of an Aggressor on the rear, I'd be far outriding the capabilities of the 100mm in the rear.
I am impressed with this Pivot though. Took them long enough to update their geometry.
I'm not asking for Minion DHFs here. My point is just that there are plenty of riding areas where a pure XC bike is the best choice overall (like when I used to live in SE Michigan). But it seems a little silly to me to have the Team builds still come with pinner tires that are of limited usefulness in day-to-day riding. At the very least, I would have liked to see the 2.35" Ardent Race up front instead of the 2.2" size at both ends. That tire is only 20g heavier than what's specced here and likely doesn't roll any slower, but would provide a bigger footprint and a little more forgiveness for general riding.
Same with the front rotor. If you're really going after it for XC races, sure, the 160mm rotor is fine. But even then, the 180mm rotor adds so little additional weight that I don't understand why it's not at least used on the Team builds.
For a race such as the NIMBY 50 (last one this Weekend) this bike with the 120 SC, dropper - real tires and larger rotors would be the ticket. Most of us mortals need things to stay upright!
It all depends on what type of riding you do. its great to have options. In British Columbia - the average XC/Marathon event or a BC Bike race type event suits James' desired spec.
me me me' attitude. These articles are free too; I often feel sorry for the guys and girls writing these articles, their efforts criticized by the same annoying readers who think they know best.
My hunch is that people who really intend to race will be more inclined to buy the World Cup bikes, while the Team ones will more likely end up with people who just want a fast short-travel machine.
For the record, XC is where my background in MTB lies, but I still believe that even those bikes should take into account how they're more realistically going to be used.
neatly? really?
What kind of leds are they using that are so annoying when they flash though?
Since boost became common and that hypasupermegaboost is a thing, can you always take the time to comment specifically on whether or not your heels were rubbing against the frame ?
Just state "no heel rubbing issues" or "no more paint on the chainstays after 1 week" , and the size of you feet.
I originally asked this question because the problem is that a single parking test or riding for 5min a test bike does not reveal the problem. And buying online makes things even worse.
I trust that pivot have done their job and thought about it, but confirming it's a non problem can only be a good thing.
Pivot, please move on from the well conceived but horrible in practice Padloc setup. We don't want to be forced into WTB grips and stupid plugs and more likely buying a new bar if we want other grips.
Well done Pivot. As a Brit I really appreciate the option to route the rear brake on the right side of the headtube. No internal guides is also lighter and really not much hassle if you're a half decent mechanic. Unfortunately Pinkbike yet again is clueless to the issue Aussies, Kiwi's and Brits suffer on this.
"Cable routing is internal throughout, using the same interchangeable port system found in other recent Pivot frames. Unfortunately, none of the lines are fully guided"
Also the numbers look pretty good too. Maybe reach is 10mm short and the headtube a little long on the medium but I could live with both.
My favourite is what Specialized do with the current alloy Stumpies. You can do what ever you want in the downtube and there's a great big hole behind the BB that goes straight into the stays. It's bloody genius.
What I didn't expect was how good Live Valve would be going downhill. I could be way sloppier with my timing on jumps, there was no unwanted compression on g-outs, and it felt more responsive in general. I can't afford it, but I'm still sold.
It feels kind of like having a bmx bike when you're pumping through rolling terrain, you can just pop off lips and build up speed more easily, but with the added advantage that as soon as you hit anything actually bumpy it softens up and saves you. It really feels like best of both worlds
Think about how platform valving changed things a few years ago. Single-pivot bikes were suddenly a lot more competitive, but the better suspension designs were just better, period.
By all means, don't take this at all to mean that I think you should get rid of your Spark. But weight isn't everything.
2013 called, they want their uninspired comment back
Reach, HT angle can be changed. Even effective ST angle to an extent. However, the two bikes are still different.
Which would put in the 90s.
There was one ride I did a few years ago on a plus bike I was testing where I didn't have the tire pressure dialed (too low), and ricocheted awkwardly off a rock at the edge of the trail. Ended up landing on my knee directly on the sharp edge of a rock. It still went through the pad I was wearing at the time (some super XCish Specialized Atlas ones) and it took me an uncomfortably long time to get the gushing the stop from the hole I ended up with, but I pretty much swore from that point forward that I was never going to go bare-kneed around here again.
If they are sticking with super boost keep it on all their bike models so pivot owners can swap wheel sets..
I would like to see the future trail 429 a bit slacker and longer with a way steeper seat tube. (like all the new bikes) and with a lighter frame.
I know we are discussing a different bike but wanted to add my 2 cents.
Ahh so LV shock open is spfter tune. I am assume (and I think I read it someplace), that the non-live valve shocks got a firmer tune. 1900 is a lot to swallow for the LV, so I am hoping to read some non-live valve reviews from some good sources. Thanks!
bikerumor.com/2019/05/20/bikerumor-podcast-013-pivots-chris-cocalis-goes-off-about-mountain-bike-design
Lots of bikes share rear-triangles between sizes, but when you specifically call out a quite large range of rider heights supported, the change in ride feel created by different chainstay to reach (and/or front-center) lengths _has to be_ discussed.
www.pinkbike.com/news/spotted-new-trek-xc-bike-nove-mesto-world-cup-xc-2019.html
Last summer I finally bought my first enduro rig, Yeti 5.5, fun bike. Anyway, this was last June, before I pulled the trigger I had the owner of my lbs get his rep on the phone and pointedly ask him "what's changing later this summer with the new update?"
"Nothing other than tubes in tubes."
"That's it?"
"Yep. That's it."
So I ordered the bike. A few weeks later the 5.5 was discontinued and the 130/150 released. But hey, they actually did come with TiTs so he only sorta lied, right? Lol. The new Top Fuel is gonna be sick, vibes to Azowehn0...
www.trekbikes.com/us/en_US/bikes/mountain-bikes/cross-country-mountain-bikes/top-fuel/top-fuel-9-9/p/28091/?colorCode=black_tealdark
this
en.wikipedia.org/wiki/French_curve
Still, on this particular bike, from the Maxxis line I would use Aspens on the dry and Beavers on the wet.