Review: The Pivot Mach SL 4 Blends XC Speed & Comfort

“Basically, we designed the bike to climb like shorter travel bikes with incredible efficiency but descend like a longer travel bike with suspension performance that really enables the rider to stay in control and go faster in technical terrain. With all Pivot designs we try to find a huge range of versatility. Designs that can be, at their core, focused on what their main job is but then also punch way outside their race category,” said Pivot’s CEO Chris Cocalis.

Pivot tweaked a few things on the new Mach 4 SL to give it its chameleon characteristics. Namely, there are four travel options in one frame. Rear wheel travel can be adjusted by a flip chip on the upper linkage. On World Cup builds, this means 95 or 103mm of travel; Team, Pro, and Ride level builds get 106 or 115mm.

I didn’t race any World Cups last summer, but I did do a few races in Colorado where versatility was key. The Mach 4 SL ended up being a nearly-perfect bike for both the six-day Breck Epic and the four-stage (single day) Durango Derby.

My test bike was the $9,899 Team XTR model in size small. In addition to the Shimano XTR drivetrain, the bike came specced with Fox Factory suspension, a Fox transfer 100mm dropper, Reynolds Black Label XC 309/287 wheels with Industry Nine hydra hubs, and Maxxis Rekon race tires front and rear.

---

---

Frame Details

According to Pivot, the Mach 4 SL’s carbon fiber frame features size-specific tuning - different carbon layups are used for each size. Visually, the tubes have a smaller diameter than other Pivot mountain bikes, and the front and rear triangles are more compact. All sizes are able to accommodate one large water bottle, and the M-XL frames can hold two. There are two bosses on the underside of the down tube and three bosses on the underside of the top tube.

This version of the Mach 4 SL shaves some 300g off the frame weight of the previous version, due in part to the switch to a vertical shock placement.

The rear-wheel travel of the Mach 4SL can be adjusted by a few millimeters with a flip chip on the rocker link. This gives riders the choice of 95mm or 103mm on the World Cup builds, and 106mm or 115mm on all other builds.

Geometry & Sizing

The Mach 4SL comes in a 100 or 120mm fork spec, with fairly significant geometry differences between the two. All versions of the bike have a slacker head angle, steeper seat angle, and longer reach than previous versions. The head angle goes from 66.7° to 68° when switching from 120 to 100, with an accompanying increase in reach of about 13mm. Seat tube angles sit at 76° on the 100mm and 74.7° on the 120mm. Chainstays are the same length regardless of frame size, measuring at 432mm.

In terms of sizing, the Mach 4 SL comes in XS-XL frames, and Pivot says the five-size range will accommodate riders from 4’ 10″ all up to 6’ 7.″ Standover clearance is generous across the range of sizes.

Suspension Design

At a time when many manufacturers are using weight-saving flex stays, Pivot has stuck with a dual-link design. The Mach 4SL continues the brand's use of the DW-link suspension design, known for its efficient power transfer and stable and consistent suspension platform. The design works particularly well for this race-oriented XC bike, where pedaling efficiency is a top priority.

Climbing

As you can imagine, the Mach 4 SL is a speedy climber. The lightweight carbon frame and DW-Link suspension system ensure that power is efficiently transferred to the wheels, which results in impressive traction and minimal pedal bob. I rarely looped out, even when pausing before technical uphill features.

On paper, the seat angle — 74.7 —seems pretty slack for an XC bike, but in real life, it doesn't feel that extreme. Remember, on a bike like this the seat angle won't change as much at sag compared to a big squishy enduro bike. Plus, the pedaling performance on the bike is just so darn good. In both travel settings, the rear suspension delivers the right amount of sensitivity and you can stay seated on all but the steepest climbs. Traction and control work in tandem on this bike — in fact, I had my best ride of the Durango Derby on the notoriously shitty, loose, and steep Animas Mountain climb. Efficiency is the name of the game on the Mach 4 SL, but there is no hidden cost in pedaling performance.

Descending

The big question was if the bike could go downhill as well as it climbed. Usually my own toughest critic, I got some really nice affirmations from buddies on late summer rides that I was descending faster than normal. I think this was largely due to the full immersion experience of the Breck Epic, but the bike definitely had something to do with it, too.

The Mach 4 SL’s responsive suspension soaks up all manner of hits, and I found it to be very forgiving for such a lightweight XC bike. The short chainstays keep things snappy, and it’s easy to maneuver the bike through tight and technical terrain. During the 'Colorado Trail' stage of the Breck Epic there's about a mile-long section of really bumpy technical rock garden where line choice is tricky and important. I saw multiple guys sitting beside their upside down bikes during that section but I managed to stay upright even if it wasn't that pretty.

Speaking of racing, the short travel setting feels decidedly 'racier,' which is to be expected, but I wouldn't describe it as harsh or less capable (remember, I accidentally did the whole Breck Epic in that setting). I just preferred the ride feeling of the longer travel setting, which was no less responsive but felt more fun and playful. Pivot says the bike is optimized for the longer travel setting, so if this were my bike I’d set it there and forget it, as I imagine most riders will do. I didn’t find there to be any disadvantage climbing in the longer travel setting, and it made for a much more pleasant descending experience.

How does it compare?

The Mach 4 SL isn't the lightest weight XC race bike out there — the small frame with DPS shock weighs in at 1930 grams — but that's likely due to the DW-link suspension design, which I think is worth the extra padding. This version of the Mach 4 SL is lighter than previous iterations of the same bike.

Even though the dw-link adds a bit of weight, it's ultimately what sets the Mach 4 SL apart from other bikes in the category. While the Orbea Oiz might have a bit more giddyup out of the gate due its low initial leverage ratio combined with relatively high anti-squat, the Mach 4 SL isn't exactly a slow starter. Plus, once it gets going, the suspension delivers a responsive and compliant throughout the ride.

Geometry-wise, the Mach 4 SL bears some similarities to bikes like the Oiz but they're not identical. Head angles and chainstay length are nearly the same at around 67 degrees and 432mm. However, the Mach 4 SL has a significantly slacker seat angle and a shorter reach when it's equipped with a 120mm fork.

Which Model is the Best Value?

The bike comes in four build options — World Cup, Team, Pro, and Ride. Pivot doesn’t downspec their carbon across the different builds, so each has the same high-quality carbon frame. Those build options are listed in descending order of price, with the World Cup — available in Shimano XTR and SRAM XX — both the most lightweight and expensive. That’s the model built around a Fox 32 fork with 100mm of travel and a Float DPS shock that switches between 93 and 105mm travel.

The Team build is essentially the same as the World Cup but with longer travel and Fox Factory Float rear suspension that flips between 103 or 115mm of travel.

Pivot says the Pro level is the most popular option. Pro comes with either Shimano XT/XTR or SRAM X0 drivetrains, and riders have the option to upgrade DT Swiss X1900 alloy wheels to the same Reynolds Blacklabel carbon that come on the World Cup and Team builds.

The lowest cost Ride build is offered in Shimano SLX/XT and SRAM GX/X01 with Fox Performance series suspension. The bike comes specc’ed with DT Swiss X1900 alloy wheels; no upgrades are available.

Prices range from the Shimano Ride build at $6,199 USD to the top tier Team XX Eagle Transmission at $11,599; needless to say, there's not exactly a 'budget' priced option.

Technical Report

TwistLoc remote grips: I wasn’t a huge fan of the TwistLoc grip. I had to position the brake lever further inboard than I wanted to because the TwistLoc is fairly wide. And while I did use it occasionally on smooth dirt roads or pavement, I don’t know that I would miss it if it wasn’t there. It is nice to be able to control the rear suspension at the grip — I did occasionally lock it out on long dirt road climbs — but the bike pedals so well you can really ride with the rear shock wide open all the time.

Maxxis Rekon Race tires: I found the dual-Rekon Race combo a little too puny for most riding. I put a Rekon on the front for the Breck Epic and then swapped the rear Rekon Race for an Ikon after I tore a sidewall riding from Silverton to Telluride. Unless they're riding very benign surfaces (or solely focused on racing), I think most people will opt to swap the tires out for something with a bit more traction and control.

---

Pinkbike's Take

---

---

Posted In:
Reviews and Tech Reviews XC Bikes Pivot Pivot Mach 4 Sl