Pivot Mach 6

We get many different bikes through our office and each has its own feel and character. Last year when we reviewed the Pivot Mach 5.7, I found something that really matched my current taste in bikes; it pedalled extremely well for a 145mm travel bike yet still offered amazingly supple suspension and above all it delivered bucketloads of fun. Everyone has individual tastes when it comes to bikes and the Mach 5.7 did it for me—I subsequently bought one.

As a 5.7 owner, I was curious to see how the new Mach 6 performed. With 155mm of rear wheel travel it offers a little extra bounce, the head angle is slightly slacker (66-degrees versus 67) and it comes equipped with a new Fox Float X piggyback style shock. As with all Pivot duallies, it employs a DW Link suspension system but the format has changed a bit. Oh, and it happens to run 27.5 wheels rather than 26-inch. While the Mach 6 is clearly an all-new model, it seems to sit reasonably close to the 5.7, at least on paper.

Carbon Cruiserweight

The Mach 6 is made almost entirely from carbon fibre. You tend to assume it’ll be light but Pivot doesn’t offer any weights within their catalogue. Stripped back to the bare frame and shock, our large Mach 6 weighed 2,890g. By comparison the Mach 5.7 is 2,530g, so the Mach 6 frame is approximately 360g heavier. Of this, 130g is due to the Float X shock; that means the Mach 6 frame and linkage assembly weighs 230g more than the Mach 5.7. This offers a pretty clear indication of where the Mach 6 is headed. Pivot talks a lot about the bike being designed for gravity enduro racing and the weight reflects this. That said, 2,890g is still pretty respectable for a frame that offers 155mm of travel.

Of course the total bike weight depends on how you spec it and the Mach 6 is offered with a choice of four different build options. There’s a Shimano XT/XTR kit, a really high-end full XTR version or you can get it with your choice of SRAM 1x11 drivechain; either XX1 or X01. Regardless of the parts spec, the Mach 6 comes with a Factory level Fox Float 34 CTD fork.

We had the Shimano XT/XTR version and it came in at 12.6kg without pedals. You’ll need to add around 300g for some pedals (as it’s tough to ride without them) and the same again for a dropper post. Sure, a dropper isn’t essential but running the Mach 6 without a height adjustable post would be like buying a carbon road bike and fitting it with old fashioned toe clips and straps. A properly equipped Mach 6 will hit the trail at around 13.2kg—that’s not light for a $7,749 carbon fibre MTB but it’s respectable for a long-travel, gravity oriented rig.

Beyond the lack of a dropper post, the only other aspect of the component spec that really didn’t sit right was the FSA stem; it just looks too skinny and XC-based for a chunky trail bike like this. The remaining parts were all appropriate, although personal preference may lead to further tweaking. Some may consider the 740mm handlebar too narrow for an all-out gravity enduro bike but this will depend on the nature of your trails—personally I can’t run bars wider than 740mm or I’ll hit the trees! Likewise, the sidewalls on the Kenda Nevegal/Honey Badger tyres are pretty light and thin; good for climbing but not burly enough if you’re going to push it to mach-six on the downhills.

Everything else about the stock build of the Mach 6 was solid and workable. The running gear is predominantly Shimano XT (the rear derailleur is the only morsel of XTR bling). Shimano’s XT brakes are amongst the best in the business and the 2x10 drivechain did everything it should. The cranks are fitted with a 24/38 chainring combo and the gear range is wide enough for just about any application, although matters of chain retention may need to be looked at if you want to focus more on gravity enduro riding. Whilst on the topic of chain retention, it’s worth noting that the Mach 6 comes with ISCG tabs on the bottom bracket—something that many considered to be a glaring omission on the Mach 5.7 Carbon.

Cable Quandary

As an all-new model, Pivot took the opportunity to work in some of the latest design ideas. Like many brands they’ve moved to internal cable routing, at least in some sections. It has a tidily executed internal guide for a stealth style dropper post. There’s no cable fishing with this; just push the housing into the port near the head tube and it simply appears inside the seat tube—nice! It’s not so nice if you don’t have a stealth-style post, as you’ll need to zip-tie the cable to the rear brake hose or improvise in some other way—it’s really been designed with a stealth post in mind.

Both the front and rear derailleur cables run internally, but only for the short distance from the head tube to the front shock mount—from that point on the cables are routed externally. As with the Mach 5.7 and other Pivot models, you need to pay close attention to the length of the cables around the shock. They bend as the suspension cycles and tend to bow outwards annoyingly if they are too long. Originally our demo bike was supplied without the cable spacer guides for the shock yoke—these stop the cables rubbing on the shock and linkage parts. Once fitted, these simple nylon spacers eliminated most of the cable rub points.

The brake hose runs externally and the bolt-on front guide is located on the left hand side of the frame. While this is great if you run the right lever to the rear brake (US style), it’s not so tidy if you prefer to have the rear brake on the left hand side (like most Aussies). Fit some protective tape to the head tube to prevent rub or route the hose around the right side of the frame and zip tie it to the rear derailleur cable.

As far as internal routing goes, the Mach 6 is reasonably easy to deal with. The inner wire slips in at the head tube and there’s a large exit port near the shock—it’s pretty hard to miss. That said, it still presents added hassle compared with external routing. To replace the rear derailleur cable for example, you’d need to remove the cover that sits over the large cable exit port. The same cover also holds the front derailleur cable in place, so you’ll need to undo both gear cables, even though there may have only been a problem with one of them.

We had to question why they bothered with internal routing at all; after all it complicates maintenance and they’ve only hidden a 25cm stretch of cable from the head tube to the forward shock mount. According to Pivot’s front-man Chris Cocalis, it buys them some extra space between the shock and the top tube which in turn lets them improve the standover clearance. It also tidies up the routing at the head tube and reduces the number of cable rub-points. As always with Pivot bikes, their design is based on function not fashion, even with a feature that’s usually employed to improve aesthetics.

Longer, Lower, Slacker

Yes, the Mach 6 has 27.5 wheels with clearance for meaty tyres but the biggest difference compared to the 5.7 lies with the overall frame geometry. The Mach 6 clearly employs the new school longer/lower/slacker design philosophy. Using a large frame as an example; the head tube is 25mm shorter while the seat tube is 40mm shorter—that’s a substantial difference. Meanwhile both the top tube and wheelbase have increased in length. Being lower has a number of benefits; there’s more room for a long travel dropper post, you’ll have more clearance over the top tube and it makes their sizing more flexible. The lower stance allowed me to go up one size (from a medium Mach 5.7 to a large Mach 6) and run a shorter stem—another new school trend.

While the front-centre has grown around 10mm in length, the 430mm chainstays are only 2mm longer than the 26-inch wheeled Mach 5.7. The other defining feature of the Mach 6 geometry is the slack seat tube angle. It starts out well forward of the bottom bracket but slopes back at a 67-degree angle. Pivot lists it as having a 71.5-degree seat angle but the effective angle and saddle setback will increase exponentially as you raise the seat post. At 177cm I’m on the short side for a large frame, yet with the saddle at full XC height, I found the seat position was a fair way behind the bottom bracket. To get my desired position and keep the front end weighted on steep climbs, I had to push the saddle all the way forward on the rails. Along with the slack 66-degree head angle, the slight rearward bias on the saddle position tilts the Pivot’s attitude a little more towards the gravity fuelled side of things.

As with most bikes in this travel category, the Mach 6 can only fit a drink bottle under the down tube; it’s an awkward spot and the bottle gets covered in mud. Most owners will wind up running a hydration pack. Pivot decided that a piggyback shock was the most appropriate choice for the Mach 6 and the additional oil reservoir leaves no room for a bottle. If you are desperately keen to run a bottle inside the frame, you can tee up a custom order and Pivot will supply the frame with a non-piggyback Float CTD and bottle mounts within the main frame.

DW Update

While it still employs the Dave Weagle patented short-link four-bar suspension design, the Mach 6 gets an added twist. Now there’s an extra link or ‘yoke’ that connects the shock with the upper link. First and foremost this affords Pivot greater control over the shock rate—something that becomes apparent once you hit the trail. It also eliminates the rear shock-eye bush, as the shock mounts directly to the yoke via a bolt-up clevis. This promises to improve durability, as the job that was done by a single bush is now handled by a pair of large industrial bearings. Last but not least, the twin bearing yoke is said to lower friction and create a more compliant rear end.

It’s also worth noting that the yoke has been designed to work with just about any standard shock. Other bikes have employed similar systems to actuate the shock but most require a proprietary shock. Flexibility in shock options is great but you do need to ensure that the rear shock eye to clevis junction remains greased and correctly torqued (15Nm). If it’s not, any lateral movement in the upper link will cause the shock eye to creak as it shifts slightly within the clevis.

Much of the suspension theory plays out on the trail. The revised linkage creates a progressive shock rate in the early travel – much like the Mach 5.7 – but where the previous design turned regressive in the latter travel, the new system remains quite linear. In plain English, it means the suspension remains extremely supple over small bumps but offers more support deeper in the travel to better handle the bigger hits. The Float X rear shock also comes to the party here; it was buttery smooth and offered a very refined feel when hitting rough terrain at speed.

By most standards, the Mach 5.7 offers excellent small bump performance. It’s one of those bikes that stays glued to the trail and makes the chatter disappear. Well the Mach 6 clearly eclipses it. Run the CTD rear shock fully open on the Mach 5.7 and it feels like the Mach 6 in the middle ‘Trail’ setting. Open up the Mach 6 in ‘Descent’ mode and it takes on the feel of a good coil-sprung gravity-rig over the small bumps. As we’ve come to expect from DW-Link bikes, the Mach 6 is brilliant over square edge hits and allows you to charge through rock gardens with great composure.

Pivot has really got the shock rate and feel of the rear end dialled. When set with 30% sag using the handy shock setup marker, it delivers amazing suppleness, regularly uses all of its travel yet never bottoms in a noticeable way and always feels composed—it’s pretty hard to fault on the way down.

All-Round Performer

When earning your fun on the way up, you’d imagine the marshmallow-like suspension is going to sap your power and wipe the smile from your face, or have you searching for fandangled lockout switches on any extended pedalling section, but this simply isn’t the case. Strong anti-squat is a key part of the DW-Link system; it uses drivechain forces to oppose your shifting body weight as you lay the power down and it makes the Mach 6 a surprisingly happy climber. In terms of pure pedalling efficiency it doesn’t match the Mach 5.7, but it still pedals well enough that you can leave the CTD shock in Descent mode most of the time—both up hill and down. Flick to the Trail setting and the bike equals the 5.7 when going up, although it’s always going to carry a bit of a weight penalty.

I was happy climbing in Descent mode; the rear end would move around a bit when out of the saddle but it never felt soggy or inefficient under power. I only employed the Trail setting for the occasional XC race or when faced with an extended road climb (the Climb setting on the Float X was unnecessary).

Of course there’s always a double edged sword with anti-squat. While the suspension doesn’t lock out under pedalling force, it does firm up noticeably and some riders may prefer suspension that’s more active (but mushy) when scaling loose and technical slopes under power—it’s really a matter of personal preference. In some situations the anti-squat force seems to enhance traction by driving the tyre into the ground.

When using granny gear (a 24-tooth cog or smaller), I could feel some feedback through the pedals, but only when soft-pedalling up rock-stepped terrain. Some people will find this ‘kickback’ annoying while others get used to it. I tried a few different chainring sizes and felt that something in the 30 to 36-tooth range offered the best blend of anti-squat qualities whilst minimising feedback through the pedals. This makes it an ideal candidate for a wide-range single chainring setup.

Once I’d moved the saddle all the way forward to counter the slack effective seat angle, the Pivot climbed the steepest trails with very little front-end wander. It certainly holds its own on the ups but once you’re up to speed, this bike just lives for rough and technical trails. The suspension is fantastic and it really lets you carry speed rather than getting hung up on square edged bumps. Although the head angle is pretty relaxed, the Mach 6 certainly isn’t lazy in the steering department. It has shorter chainstays than many 27.5 trail bikes and the overall wheelbase isn’t excessively long. This makes for a bike that’s easy to manual and toss around on the trail, in fact the Mach 6 pretty much begs you to ride it that way—like a hyperactive child who’s overdosed on red cordial. While Pivot has changed a lot on this bike, and they have made it more surefooted when gravity calls, they haven’t lost the heart and soul of the Mach 5.7. It remains a tremendously fun trail bike that’ll take you well over your head and bring you out the other side laughing.

Thumbs Up

Fantastic suspension performance

Playful and surprisingly agile ride

Pedals very well for a plush long-travel bike 

Thumbs Down

Some pedal kick-back in granny gear

Slack seat angle may hinder on steep climbs

Cable routing

Specifications

Frame: Hollow Box Carbon DW-Link

Shock: Fox Float X CTD 155mm travel

Fork: Fox 34 Float CTD 15QR 150mm travel

Headset: Pivot Sealed Bearing, 1 1/8 - 1 1/2

Handlebars: Pivot Carbon 740mm

Stem: FSA SLK 60mm

Shifters: Shimano XT

Front Derailleur: Shimano XT

Rear Derailleur: Shimano XTR Shadow Plus

Cassette: Shimano XT 11/36 10-speed

Chain: Shimano XT

Cranks: Shimano XT 24/38

Bottom Bracket: Shimano

Pedals: N/A

Brakes: Shimano XT

Wheels: Stan’s ZTR Arch EX

Tyres: Kenda Nevegal/Honey Badger

Saddle: WTB Vigo Race

Seatpost: FSA SLK Carbon

Weight: 12.6kg without pedals (Large frame 2,890g)

Available Sizes: XS, S, M, L (tested), XL

Price: $7,749

Distributor: Jet Black Products (02) 4560 1200 / www.pivotcycles.com