With a week on the trails of Rotorua on the horizon, Flow handpicked four of the new breed of 27.5″ trail/all-mountain bikes to put to the test. One of these was Pivot’s mouth watering Mach 6 Carbon, a bike we previewed a couple of weeks ago on our home trails.

Design:

All carbon and all glorious, the Mach 6 is only a small step up in the travel stakes from the legendary Mach 5.7, but it’s quite a different beast. First of all, the wheels are a little bigger – it’s one of three new 27.5″ bikes in the Pivot lineup. Secondly, it shuffles towards the descending end of the spectrum a bit, with slacker angles, a lower bottom bracket and FOX’s premium Float X shock. Pivot built this bike with Gravity Enduro racing in mind, you know.

Even with 155mm rear travel and 160mm front, the Mach 6 avoids being all Missy Piggy on the climbs, thanks to a low overall weight of just under 13kg, and perhaps the best suspension system on the planet – the DW link. Combine the DW link’s spritely responsiveness under pedalling with the on-the-fly compression adjustment of the CTD shock and you’ll spin your way up just about anything. The riding position is very upright for long climbs, but who’s racing the ups?

Small bump response and durability are both given a boost with the new linkage configuration employed on the Mach 6; the shock itself is driven by a separate strut that rotates on cartridge bearings and this eliminates the need for a DU bush. Winning.

Keeping the rear end tight with a bigger wheel and this much travel needed some smart thinking; to fit it all in (and still facilitate a front derailleur) Pivot gave the rear triangle a single spar on the non-driveside. Big bearings in the lower linkage and a 142x12mm DT-made axle ensure the rear end is kept sufficiently stiff.

An uninterrupted seat tube lets you lower the seat post all the way, but this bike really needs a dropper post (there are cable routing provisions for an internally routed ‘stealth’ post). One casualty of the compact frame and whopper shock is water bottle mounts, but in this arena of riding, most riders will be using hydration packs anyhow.

We mentioned it before in our First Bite, but the cables created all kinds of headaches for us. With the muddy conditions we rode in, cable rub was a big problem and we had some serious paint and carbon damage around the upper linkage. Use cable rub stickers aplenty.

The Build:

Add a dropper post and change the rubber and you’ve got a pretty much flawless build kit. We like the soft compound of the Kenda tyres, but some sturdier rubber wouldn’t go astray here, especially on the rear, given how hard you can hammer the rear wheel into holes and bumps.

The Shimano XT brakes and XT/XTR drivetrain will keep at it forever, and if you’d prefer to run a single ring instead of the supplied 24/38 double chain ring arrangement, then there as ISCG tabs to do so.

Stan’s No Tubes Flow EX rims are a great choice for this bike, with a 23mm-wide rim bed to support big tyres, plus they’re tubeless ready.

Ride:

For a bike with burly intentions, the Mach 6 felt a little bit ‘small’ at first – the medium frame doesn’t have the stretched out top tube of some all-mountain bikes, and the stem is a bit longer than you’d normally see on a bike with a 160mm fork. But any worries we had in the carpark about this making the Pivot nervous on the descents disappeared once we aimed it downhill.

This bike eats it up, the rougher and rootier the better. With the short rear end (430mm stays) and slack head angle, the Mach 6 lives on its rear wheel; open your stance up, move your body weight rearward a touch and this bike smashes it! You can pop the front wheel up, letting it skim across the rough, while the rear suspension gobbles everything up. There’s never a worry that rear end is overworked, it’s superb, like a downhill bike in the way it handles repeated hits. It’s absurd how much momentum you can carry.

The combination of a wide handlebar and compact overall bike size makes it easy let the bike move underneath you, something we really appreciated on the slippery, rooty trails. Even when the bike breaks traction or you find yourself off line, it’s very easy to keep that body and bike separation – on some bikes you feel like you’re going down with the ship as soon as wheels begin sliding, but on the Mach 6 it’s easy to let the bike sort itself out and you just worry about what’s coming up next.

The FOX 34 CTD fork is classy too. FOX have addressed the concerns that their 2013 forks were too linear in their action and have given the new range a far more progressive spring curve. We ended up running the pressure quite low to get the correct sag and found ourselves relishing the confidence and traction provided by the supportive damping and stiff construction.

Overall:

Of the four bikes we took to Rotorua, this is the one that put the biggest grins on our faces when it counted. It’s fast, it’s eager to get wild, it’s light and beautifully made (except for those cables!) and it has that classic Pivot ability to get you into, and back out of, situations that would see you crashing on a lesser bike. Keep the sizing in mind, as some riders will want to go up a frame size and run a shorter stem, and negotiate to have a dropper post fitted too before you leave the shop. As an all-mountain / gravity-enduro steed, this is a hard effort to top.