Pivot Mach 4SL gets faster, lighter & adds dual travel modes

Apr 18, 2023

Put side by side, the new Pivot Mach 4SL looks quite like the one launched in 2019, but there's a lot that's different…and better.

It drops almost a pound off the frame, has two travel options, each with two travel adjustments, with 95-103mm travel on World Cup builds, and 106-115mm travel on the others.

It adds more storage options, and it's also a bit longer and slacker. All together, it makes it a more versatile race bike than ever, working for everything from short track to XCO to marathon to multi-day epics.

Pivot's goal was to "Challenge the threshold" with this bike. Taken two ways, it's a bike that lets you push your own limits, but it also pushed their engineering team to design it.

Two main goals were "How much weight could we save out of this frame?" and "How can we make the suspension more playful without giving up efficiency?". After all, it still needs to ride like a Pivot.

Founder Chris Cocalis said that while other brands had saving weight as a top priority on the newest bikes, Pivot's focus was on suspension performance. So while other bikes dropped travel to 90mm or even as low as 60mm, and/or moved to a pivot-free rear dropout area by using a flexible seatstay, Pivot stuck with their DW-link design and looked at ways to refine it and the frame to improve performance.

Their rear triangle, by the way, does not have a pivot near the rear axle, but does use a lower rocker arm connecting the one-piece rear triangle to the frame, and the top of the triangle pushes a rocker arm forward, which pushes the vertically-positioned shock downward.

Fun fact, the prior Mach 4SL was the first of their modern bikes to have a vertical shock layout, which allowed for a lower top tube and standover, lower center of gravity, and still allow for a water bottle inside the front triangle. This new bike keeps that design.

And, yes, shave a few grams.

Actually, more than a few. The new Mach 4SL is 300-417g (0.65-0.9lb) lighter than before, depending on frame size.

Linkages were one area where they saved a lot. They’re forged 7000-series aluminum that's then machined, making it a lot leaner than before.

They skipped any internal sleeves for cables and hoses, which can add ~30g per line, and they limit the ability to run the brakes moto style. All all bikes ship with Jagwire foam sleeves over the hoses inside to keep things quiet, and the cable port covers lock things down to prevent looseness and rattles.

They even selected a paint that only adds about 25g, which is really light for a full coat of paint.

Claimed frame weight for the Size Small is just 1,660g (3.65lb) w/o shock, and 1,930g (4.25lb) w/ Fox DPS shock.

Complete bike weight is under 23lbs for the SRAM XX SL World Cup build, dropper seatpost, 29×2.4 tires and 30mm wide carbon rims.

As great as weight savings are, the most interesting feature of the new Mach 4SL is the way it changes its personality and travel.

Some recent bikes have shortened rear wheel travel to maximize efficiency. Pivot wanted to make it more capable, so shortening travel was definitely not a way to do that.

So they (mostly) went longer. By swapping rear shocks, you can get 95-103mm of rear travel with a 40mm stroke shock, or 106-115mm with a 45mm stroke shock. Both shocks use the same eye-to-eye length, so geometry doesn't change when changing the shock, nor when changing modes (the Forks do, though, as the shorter stroke bikes get 100mm Fox 32 SC forks, the longer stroke ones get Fox 34 SC forks and will be slacker).

The prior model had a fixed 100mm rear travel, a new flip chip at the upper shock mount lets you switch between two different travel settings for a given shock. But it changes more than just travel, it completely changes the bike's personality.

With the shock in the rearward position, it has more travel and the rocker has more leverage over it, making for a plusher, more playful bike.

Move to the forward position and there's less leverage, so it's firmer and more efficient.

The switch only moves the upper shock mount by 5.2mm, but it feels like a world of difference. The bike goes from squishy and fun to firm and fast (but still pretty fun).

As for the kinematics, the suspension has a rising rate until the rocker hits 90º to the shock, and then it's a falling rate, which helps it push through the last bit of travel as the shock ramps up. The combination gives them a constant progression, preventing you from blowing through the travel but still letting you use all of it.

For the longer-travel builds, which Pivot anticipates being 97% of their sales, the specific (average throughout the travel) numbers are:

The longer travel setup is designed specifically around the air spring curve of the new Float rear shock. Despite the extra travel, Pivot says the longer travel version pedals even better than the prior Mach 4SL, which was already a really good, fast bike.

For the shorter travel World Cup bikes, however, the existing Fox DPS shock worked well but begs the question, why not spec the new Float SL for the lightest bikes?

Cocalis says the DPS weighs about the same as the Float SL, there's still a lot of inventory of the DPS while the Float SL isn't really available yet, and they did all the testing with the DPS since this bike was in development 2.5 years ago.

So, the Float SL will likely sub in after they’ve done all of the tuning and testing with it. But also, only about 3% of their sales will be the short travel model, so…NBD?

Speaking of tuning, they spec lighter shock valving for XS/Small frames.

Lastly, you won't find Live Valve suspension on it, only manual lockouts. Which, for a brand like Pivot that's been a big fan of Live Valve since its inception, may seem odd. But, let's be real, Live Valve has been out for a while, and if patent filings are viewed as reading the future, chances are something new is coming soon enough that it didn't make sense to build all of the extra mounts and wire ports into this bike if they’d be outdated soon.

Read into that what you will, but Pivot added that putting those holes and ports and mounts into the frame didn't fit well with their stiffness and weight goals for this frame either.

They also added that the they designed this bike to perform extremely efficiently under pedaling, minimizing the difference between the old bikes with Live Valve and these bikes without them. Speaking of holes in the frame…

Two things that you won't find here are stealth cable routing and threaded bottom brackets.

For the cables and hoses, they do run internally, but you won't find Pivot running them through a headset cap anytime soon on their mountain bikes.

Why? "We feel it really complicates the angles of the cables, and they aren't optimized at those angles," says Cocalis. "It's also not optimum for the headset, and it creates entry points for water, etc. We’re just not there yet."

For the PF92 bottom bracket, they do their own machining and facing of the carbon shell to a much higher standard than you’ll find in most places, which has led to them not having any issues with creaking.

And, for Race Face cranks, they use a custom-designed Enduro bearing with double-row bearings that makes it bombproof.

All frames have size specific layups and tube shapes and diameters. Combine that with the varied shock tuning and you get bikes that should feel and perform similarly for all rider sizes.

Gone are the five mounting points on the downtube that allowed XL riders to fit two short bottles there. Now, Medium and larger frames can fit two water bottles using the accessory mounts under the top tube, but all sizes will fit a large water bottle on the downtube. And there's an extra mount under the downtube, too.

Why not internal storage? Because it adds weight.

You can use the top tube mounts for an extra bottle cage or tool and wrap mounts, and there's an additional flip-flop panel under the BB that can be used to mount some Topeak Ninja tool kits (it's where the Di2 battery went on the prior models to power the Live Valve system).

Interestingly, they pay quite a bit of attention to their cockpit parts, too. Their MTB flat handlebar is 35mm x 760mm, and is designed by them, with a layup specifically designed for compliance where it counts, measuring to be as "comfortable" as some other very popular handlebars on the market. Which basically means two things: It's not just some generic carbon bar they slapped a label on, and it's not something you’ll need to upgrade anytime soon.

All bikes come with a rear lockout using the Rockshox TwistLoc remote, and World Cup models add another line coming out of that to simultaneously lock out the fork, too.

The 4SL uses normal Boost axle spacing because they wanted to fit the narrowest Q-factor cranks from Shimano, even though they spec Race Face cranks on all of the Shimano builds (because they generally better availability and cost less).

That let them use 52mm chainline chainrings for the SRAM XX SL and Shimano+Race Face builds, which is better for an XC bike than the "do it all" 55mm chainline that's coming on a lot of cranks nowadays, including the new XO T-Type cranks.

The chainstays clear up to a 38t chainring, and the bikes fit 29×2.4 tires, with the caveat that they mean rounded-profiled 2.4 tires like a Rekon Race, not an aggressively knobbed DHR.

Brake mount is designed for a 160mm rotor, but it’ll fit any 180mm rotor with an adapter except Hope.

Reach and wheelbase are longer and the head angle is slacker… 0.5º slacker with a 100mm fork, and 0.9º slacker with a 120mm fork.

Whereas the prior model's geometry was designed around the 120mm fork, this one was actually designed around the shorter travel WC models first, even though they expect those shorter travel builds to be only about 3% of sales.

Once that was dialed, they put the 120mm fork on it and made minor adjustments, dropping the BB and steepening the seat angle a bit more so that it hits the right spot for both builds. Technically the BB height is about 0.4mm higher than before, but all bikes now come with 2.4″ tires rather than 2.2″, which raises things up. The new geo puts the WC bikes in a slightly more aggressive position than before.

All models come in light blue or green in sizes XS to XL, with Shimano and SRAM drivetrain choices at each spec level. Key differences between the World Cup and other models is the use of the Transfer SL dropper post versus standard Transfer posts.

The Ride and Pro models come with DT Swiss alloy wheels, all others get wider Reynolds Black Label carbon wheels with Industry Nine Hydra hubs, and Pro has the option to upgrade to carbon. Click any image to enlarge.

Bikes are available now. Stay tuned for first impressions and ride review.

PivotCycles.com