The carbon fiber Top Fuel ruled in mountain biking’s mid-2000s heyday, and now it’s back and better than ever.
Most importantly, Trek has updated the geometry of its top-flight, full-suspension race bike. New, more playful geometry (including a 70-degree head angle and shorter chainstays) will keep downhill demons happy but does nothing to diminish the bike’s race-bred intentions.
The Bontrager tires are thin and light, with minimal tread. That’s fine for bombing around on hardpack, but they are quickly out of their depth on anything more technical. The rest of the build is solid, race-worthy, but not too light for the weekend warrior. The combination of a SRAM X1 drivetrain and Shimano XT brakes is tried-and-true, and works splendidly.
Few race bikes boast a pedaling platform as formidable, yet responsive, as the Top Fuel’s. Reaction under braking is particularly good. Stand out of the saddle and the whole thing firms up, but let loose on a downhill and it’s plenty active, with a predictable, smooth curve.
Trek’s size-specific wheel diameter is smart. It puts smaller riders on more nimble 27.5-inch wheels and larger riders on a 29er. We’ve long held that 29er wheels are just too big to work well on small frames, at least without major geometry compromises.
Component highlights: SRAM X1 drivetrain; RockShox SID XX fork paired with Monarch XX rear shock; Bontrager XR1 Team Issue tubeless wheelset