Pivot Mach 5.5

With massive 27.5×2.6-inch Maxxis Minion tires wrapped around Reynolds carbon wheels and a Fox 36 Factory shock with 160 millimeters of travel, the Pivot Mach 5.5 descends technical singletrack with aplomb. Yet the 140 millimeters of rear travel from the Fox Float Factory
DPS EVOL root the Mach 5.5 solidly in the trail bike realm. It also means the bike has the legs for a climb.

It turns out, the Mach 5.5 looks bigger than it really is. It certainly doesn’t look like a bike you’d want to push up the mountain. Does that seemingly unbalanced combination work both up and down the trail?

Yes, thanks in large part to Pivot’s DW Link suspension design and some relatively conservative geometry decisions.

A 73.5-degree seat tube angle positions the rider further forward over the pedals. This yields a better leverage point during climbing. In other words, pushing from behind the pedals is generally less efficient than pushing over them. That means the Mach 5.5 is much more agile
than its big stature would imply.

Still, there are a few compromises, as there are with any trail bike attempting to do it all. If you’re looking for XC climbing performance, you might be let down. If you’re looking for better-than-average climbing for a trail bike, the Mach 5.5 easily eclipses that standard.

What holds it back? Mostly the massive tires. Swap them out for something skinnier — say, 2.3- or 2.4-inch tires rather than the massive 2.6-inch tires spec’d on our test bike — and suddenly you have a different animal. That’s part of the Mach’s charm: You can change its personality with a few build modifications. We’d be comfortable taking this to the local lunch loop, but equally comfortable pushing its limits in Moab.

There are, of course, advantages to those big tires, including added traction. Run them at low pressures for a big contact patch and watch those tires grip and bite in the corners. And lowering the pressure also makes the 140 millimeters of rear suspension feel just a bit longer.
Sure, tire-pressure suspension is not exactly refined travel on the bottom end, but it helps you avoid that end-of-the-stroke clunk. The Mach 5.5’s small bump compliance is excellent; it’s possible the big tires have something to do with that, in addition to the suspension.

The Mach 5.5 is rowdy enough to handle high-speed descents, and airing it out feels second nature. A 66.5-degree head tube angle complements the 460-millimeter reach and short rear end to create an incredibly balanced riding position. And the DW Link suspension felt mid stroke plush almost all the way through the travel. Only the chunkiest descents will push this bike to its limit.

Our test bike came with a superlative Shimano XT/XTR build kit and upgraded carbon Reynolds wheels. The Fox Transfer dropper post is an excellent addition to a phenomenal build. If the associated price tag is too rich for your blood, you can opt instead for the Race XT build which runs $5,000.

At first glance, it’s hard to see where the Mach 5.5 fits in the grand scheme of trail riding. It’s almost an enduro bike, has the essence of an XC bike, looks plus-sized, but remains lithe. It would be too easy to say this bike is a jack of all trades and a master of none, yet somehow the Mach 5.5 excels at nearly everything. It’s a true chameleon capable of rowdy enduro lines one moment and sustained climbs the next.

For our tastes, we’d probably swap out the massive tires in favor of something a bit lighter and more nimble to make climbing more manageable, but otherwise, the Mach 5.5 is comfortable in its own skin.

We’d take it just about anywhere.

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