This bike needs better brakes. I normally don't nitpick build kits until around paragraph three, but that's not my point. My point is that the Trek Full Stache is so capable, so monstrous, even its creators underestimated it. To be fair, I did too. My other experiences with 29+ were with Trek's own Stache 9.8, a surprisingly nimble trail hardtail, and Salsa's Deadwood, a conservative but adventurous full-suspension bike. Both are good at what they do, but neither excels at high speed. The 130-millimeter travel Full Stache does. In fact, I can't point to any bike south of 170 millimeters that does a better job straightlining full speed through the confounding messes I like to call trails. It just has a problem slowing down. But I'm getting ahead of myself again. Ride impressions start at paragraph four. First, let's talk about the bike itself.

The Bike Itself

The elevated chainstay carries over from the hardtail Stache and other 29+ bikes. It allows for an impressive 430-millimeter rear center, but it’s responsible for some noticeable frame flex. Photo: Satchel Cronk

Aside from its short-as-possible headtube, the Full Stache front triangle is pretty traditional. But its short-as-possible chainstays mean the rear triangle is anything but. Beyond the elevated driveside stay is its nuanced linkage. You'll notice it's technically a Full Floater, but a traditional Full Floater lower eyelet moves parallel to and away from the path of the upper eyelet. On the Full Stache, that floating lower-shock mount moves toward the upper eyelet, though not straight towards it. This means it adds a slight bit of progressivity, but that’s not necessarily why it’s featured on the Full Stache. Trek went Full Floater primarily because the Full Stache main pivot had to sit farther forward, and the shock simply had nowhere better to be. The end result is a 430-millimeter chainstay, shorter even than that of the Fuel EX 29. That's even accommodating particularly voluminous 29×3.0 Bontrager SE4s, truly an aggressive tread for the plus-size realm.
For now, this is the only build kit the Full Stache comes with, and it's only available in aluminum. At 33.4 pounds, it's not light, but the bike's nature hides its weight well. At $3,700, it's a reasonable value, and it puts that value where it counts. GX Eagle, Pike RC and a 3-position Float EVOL shock with Trek's Re:Aktiv damping. But those Guide R brakes and 180-millimeter rotors did not measure up.

Fast, but not loose

Riding deep backcountry usually means riding safe. The Full Stache inspires Trek’s Travis Brown and Bike Mag’s Will Ritchie to do otherwise. Photo: Dan Milner

Exactly why I keep mentioning the brakes goes beyond just the Full Stache's ample appetite for rowdy terrain and high speed. It's the traction it offers while you're on that terrain and at that speed. When things get out of control, there's always enough grip to reel you in. The same is true when navigating down sections you'd forgive yourself for walking. The Full Stache lets you safely carry speed on slippery slopes where speed is normally the enemy. But the big tires offer so much bite, and the big wheels have so much leverage, that I would out-ride the Guide Rs no matter how hard I pulled them. I was always leaving traction on the table when I wanted it, and it was difficult to skid the tire when I didn't. So, I plugged in some 203-millimeter rotors and metallic pads. They offered nearly all the power I was lacking, and they allowed me to chirp the rear tire loose when I needed. They bring out the bike's unique potential for both recklessness and safety.

The Full Stache's geometry lends itself to the same aggressive riding that its tires do. A Large frame has a 480-millimeter reach and 49 millimeters of bottom-bracket drop in the low position. That checks the 'long' and 'low' boxes. But 'slack' is relative. The 67-degree head angle rides more relaxed than it reads thanks to those big wheels.
The real geometry highlight is the short chainstays. Like the Stache hardtail, the elevated driveside stay allows the rear wheel to sit tightly against the bottom bracket. It makes behind-the saddle steeps even easier to control and makes lifting the front wheel feel natural. I'm not saying the Full Stache feels playful or nimble, but it doesn't feel foreign. The bike interacts with the ground in altogether new ways, but it interacts with you more or less like any other bike. Provided, that is, that you are at least of average height. There is no small-sized Full Stache.

There’s no end to the places a bike like the Full Stache can take you. Photo: Dan Milner

The elevated chainstay makes that short rear center possible, but it leads to some frame flex. The back end feels vague when you punch it into a berm or pull up at an angle. And in the lower gears, the wheel can actually flex the frame enough that the tire will occasionally rub the chain. After I upgraded to Bontrager's Line 40 carbon rims, I found much of the flex disappeared. But under forceful riding, the flex is still there, and it's not subtle like non-Boost vs. Boost, or Bon Scott vs. Brian Johnson. It's significant, like Axl Rose vs. Brian Johnson. But realistically, there will always be vagueness with 3.0-inch tires at 15 PSI. The bike is already cloud-like, so that lateral float doesn't feel out of place. All things considered, it's a small price to pay for what this bike offers. And by the way, Axl is doing a fine job with AC/DC.

It's a long way to the top

The Full-Floater is back on the ABP-suspended Full Stache. Also back is Re:Aktiv, Trek’s incredibly effective supportive-yet-supple damping system. Photo: Satchel Cronk

On my first rough climb with the Full Stache, I thought my eyes were playing tricks on me. Every line I picked rode much smoother than it looked. I was able to stay in the saddle and maintain my cadence and momentum through sections that would hang up a traditional bike. The feeling was qualitatively new. It floats up loose, bumpy climbs like nothing I've ever ridden, but that's not to say it does it quickly. It's still a lot of bike, and all of its rubber turns from asset to liability as soon as the trail smooths out. But the same can be said about rear suspension. To that point, the rear shock's 'Firm' setting is uniquely useful on the Full Stache. If I wanted to hustle, the lockout still left me with the traction and comfort of the huge tires. The rest of the time, the Re:Aktiv damper helped keep it riding high, and the 75-degree seat angle helped me put the power down.

Shade is at a premium at high noon in Puna de Atacama. Photo: Dan Milner

I haven't even touched on the Full Stache's potential for bikepacking. Rowdy terrain is now in reach of multi-day trips and the vertically mounted rear  shock still provides decent room for a frame bag.  You can read about the Full Stache tackling the desolate reaches of Argentina's Puna de Atacama in "Hollow Be Thy Name.” One thing's certain though: While the Full Stache seems to be good at going far, it's even better at going fast.


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