Pivot launched the new third-generation Mach 4 SL XC mountain bike – A LOT lighter & more adjustable

Cross-country racing in XC is a field marked by maximum heart rate, aerobic and lactate thresholds, where reducing load is more important than anything else. In the past, this single focus has led designers to compromise on suspension performance, frame stiffness, handling integrity and ride quality.

An overview of the Pivot Mach 4 SL

The Pivot Mach 4 SL is a short travel XC race bike that’s designed to compete with the likes of the Giant Anthem, Scott Spark and Specialized Epic World Cup.

While it looks similar to the old version, the frame is all-new for 2023. It draws a lot from the development of the latest Les SL hardtail, with the primary goal being to reduce overall weight.

Compared to the previous model the tube profiles are notably slimmer, the linkage has been pared right back, and the carbon layup has also been updated. The rear brake mount now sits on the chainstay, which allows the seatstay tubes to be made thinner and lighter.

Furthermore, each frame size is said to have undergone an independent strength-to-weight analysis to ensure that overall stiffness and ride quality is consistent across the range regardless of rider height.

It’s gotten much lighter

The result of all this crafty carbon engineering is a claimed weight reduction of 300-400g. That represents an enormous drop of around 17% over the previous version, which is huge!

According to Pivot, a Medium size Mach 4 SL frame weighs 1,975g including the shock. After some digging, it turns out that this number doesn’t include any hardware. Once you add in all of the cable ports, Tool Dock cover and the very generous amount of frame protection, the claimed weight grows to 2,087g. Here’s how that number compares to the claimed weights from Pivot’s competitors;

As you’ll see from that list, the Mach 4 SL isn’t the lightest XC bike on the market. However, it is the only one that doesn’t use a flex-stay suspension design, so we’re not exactly comparing apples to apples here.

It would seem that apples are hard to find too, as there are very few bikes on the race circuit that use a multi-link platform. The BMC Fourstroke is the most well-known example, and that frame is claimed to weigh 2.4kg with the shock and hardware. That is quite a bit heavier, and it makes the Mach 4 SL’s svelte figure all the more impressive.

Dual-link, dual-travel suspension

Just like its predecessor, the new Mach 4 SL is designed around a 100-120mm travel fork.

The World Cup models come with a 100mm Fox 32 Step-Cast fork, while the standard models are equipped with a 120mm Fox 34 Step-Cast fork. Rear travel is also different between the two builds.

The World Cup bikes feature a shorter 40mm stroke shock that delivers 95mm or 103mm of rear travel, depending on the flip chip setting. In comparison, the regular Mach 4 SL models utilise a 45mm stroke shock that produces 106mm or 115mm of rear travel.

The two-position flip chip is located at the upper shock mount. It’s claimed to only affect the rear suspension, with the geometry remaining the same between the two settings.

Controlling rear travel is an updated dw-link suspension platform. The one-piece swingarm connects to the front triangle via two 7000-series forged alloy links and custom Enduro Max bearings.

Having given up any provisions for Live Valve, the Mach 4 SL frame is said to be both lighter and easier to manufacture. It’s also much neater without the Live Valve battery, sensors and the associated tangle of wires. However, given there have been wireless Live Valve prototypes floating around the enduro race circuit over the past year, perhaps the new Mach 4 SL is proof that the next iteration will indeed be wireless.

Refreshed geometry

There have been some notable updates to the Pivot Mach 4 SL geometry, which varies depending on the fork travel.

With a 100mm travel fork the head angle is 68°, the effective seat angle is 76° and the reach on a Medium frame is 450mm.

With the 120mm fork the head angle kicks out to 66.7°, the seat angle to 74.7°, and the reach shrinks to 437mm.

All five frame sizes feature the same 432mm rear centre length, and the swingarm will handle up to a 2.4in wide tyre. Pivot has achieved this with conventional Boost hub spacing (no Super Boost here), and most models feature a 52mm chainline to keep the Q-factor nice and narrow.

Despite featuring an impressive amount of standover clearance, each frame size will accommodate a large-size bottle. The Medium and above will actually fit two bottles inside the front triangle, and there’s a third mount underneath the downtube along with Pivot’s Tool Dock system.

Pivot Mach 4 SL price & specs

There will be eight build kit options across the Pivot Mach 4 SL range for 2023. Prices will start at $10,499 AUD for the Ride SLX/XT model, and will top out at a valiant $19,499 AUD for the Team XX Eagle Transmission bike.

The Mach 4 SL frameset will be offered separately, but we won’t see those arriving in Australia until 2024.

As part of the official launch of the Mach 4 SL, I was invited out to Cortez in Colorado where I had the opportunity to test out the Team XTR model. While I am eager to ride it on home trails to compare it directly with some of the other XC bikes we’ve reviewed lately, I managed to put in over 130km of riding in during the week to get a solid impression of what the Mach 4 SL is all about.

2023 Pivot Mach 4 SL Team XTR

Frame | Full Carbon, dw-link Suspension Design, 106mm or 115mm Travel

Fork | Fox 34 Step-Cast, Factory Series, FIT4 Damper, 2-Position w/TwistLoc, 44mm Offset, 120mm Travel

Shock | Fox Float, Factory Series, 2-Position w/TwistLoc, 190x45mm

Wheels | Reynolds Black Label 309/289 XC, Carbon Rims, Inner Width: 30mm Front & 28mm Rear

Tyres | Maxxis Rekon Race EXO 2.4in Front & Rear

Drivetrain | Shimano XTR 1×12 w/34T Race Face Next SL Crankset & 10-51T Cassette

Brakes | Shimano XTR Race 2-Piston w/160mm CenterLock Rotors

Bar | Phoenix Team Flat Carbon, 760mm Width

Stem | Phoenix Team, 60mm Length

Grips | SRAM TwistLoc Lock-On

Seatpost | Fox Transfer, Factory Series, Travel: 125mm (XS-S), 150mm (M-L), 175mm (XL)

Saddle | Phoenix WTB Volt, Carbon Rails

Confirmed Weight | 10.91kg

RRP | $16,499 AUD

Pivot Mach 4 SL sizing & fit

At 175cm tall I’ve been riding a Medium size in the Pivot Mach 4 SL.

With the stem in a neutral position and the 120mm fork propping the front end up, the riding position is comfortable and easy to get used to. While it does feel sporty, it’s not as aggro as some other XC bikes like the Canyon Lux World Cup or Merida Ninety-Six RC. No doubt you could achieve a lower and more stretched-out racing position by flipping the stem or running a shorter travel fork, and it’s good to see plenty of steerer tube for dialling in your preferred bar height.

The grips are nice and tacky, and while I don’t love the Volt saddle, it’s been plenty supportive on some of the longer rides we’ve taken the Mach 4 SL on.

Suspension setup

As with all Pivot full suspension bikes, the Mach 4 SL comes with a small clip-on sag indicator for the rear shock. I’ve banged on about this before, but I’ll mention it again since it’s such a brilliant aid for helping riders to get their rear suspension set up properly.

The sag indicator has two lines on it to denote two different sag positions; Race (26% sag) and Trail (31% sag). Of course you can set it up anywhere in between, though given this is an XC race bike I went with the former setting. I needed 140psi to support my 68kg riding weight, and I set the rebound damping one click faster than halfway (8/14 clicks).

Inside the air can is a 0.5³in volume spacer, which gives you plenty of options for going bigger or smaller should you wish to fine-tune progression.

It’s worth noting here that the internal compression and rebound tune on the Fox Float shock is lighter on the XS and S frame sizes. The idea here is to provide a more appropriate level of damping for the smaller and lighter riders that are likely to be aboard on those bikes.

Pivot Mach 4 SL weight

My Pivot Mach 4 SL Team XTR test bike came in at 10.91kg. That’s without pedals and with the tyres set up tubeless.

You may spot the Rekon front tyre in the photos, which is a deviation from the standard spec. Stock bikes will come fitted with Rekon Race tyres front and rear, so they’ll be marginally lighter.

Regardless, the sub-11kg complete weight is impressive given this is a proper dual-link suspension bike with high volume rubber and a long-stroke dropper post.

Adaptable suspension

Serious racers will likely look straight to the World Cup models, which offer a weight advantage thanks to their Fox 32 Step-Cast fork, shorter travel Transfer SL dropper post and smaller Fox Float DPS shock. They also come with a 3-position TwistLoc remote and a firmer compression tune for the shock’s climb mode.

A lot of riders are looking for a little more travel from their XC bikes these days however, and so the regular models are likely to be the more practical and versatile choice.

Whichever model you go for, the fact that you can change the fork and shock travel gives you useful options down the line for adapting the setup as your riding (or racing) evolves.

In the 106mm travel setting, the leverage rate is lower overall but especially towards the end of the stroke. The result on the trail is that the suspension is considerably firmer and even more responsive under power. In this setting I found the TwistLoc remote was almost redundant since the bike pedalled so damn well. And because the back end sat up even higher in its travel, I found the steering was a little sharper and more direct, giving the whole bike a racier feel from tip to tail.

What didn’t we like?

Obviously the price of entry for the new Pivot Mach 4 SL is high. Then again, this isn’t a bike that’s trying to compete at the low-end of the market. Much like Santa Cruz, Ibis and Yeti, Pivot Cycles isn’t a budget brand. The Mach 4 SL is a seriously premium product, and Pivot would point towards the frame construction, materials and manufacturing tolerances to justify the high price tag.

It’s also worth noting here that while Santa Cruz and Yeti produce their carbon frames in two tiers so that they can offer cheaper complete bikes, Pivot only makes a single tier for its carbon frames. You won’t find an alloy version either, though not many brands do in the XC space. The Orbea Oiz is a notable exception, and it means the entry price is quite a lot lower.

Flow’s Verdict

The new Pivot Mach 4 SL has taken everything that we loved about the original model, and turns the dial up several notches.

Thanks to its svelte tube profiles and chiselled linkages, it’s significantly lighter than its predecessor. It isn’t exactly the lightest XC bike on the market, but it isn’t that far off despite having retained the excellent dw-link suspension design. I’m glad Pivot stuck to its guns and avoided going down the flex-stay route too, as the suspension performance is a huge contributor to why this bike rides so damn well.

The addition of a new two-position flip chip adds useful trail-tuning adaptability, and the capacity to run different length shocks and forks gives further options for dialling in the handling and suspension performance.

Combined with the excellent geometry and well-considered build kit, the Pivot Mach 4 SL presents as a highly capable and efficient XC bike that thrives on technical terrain.