Tested: 2008 Trek Fuel EX 9

The first thing you notice about Trek’s new Fuel EX 9—an aluminum 5-inch trail bike—is the unusual rear pivot. It’s located around the axle, with its bearings tucked neatly into the intersection of the chainstays and seatstays. This is the much-hyped ABP (Active Braking Pivot), Trek’s attempt to solve the problem of braking forces lousing up suspension performance.

The rocker and swingarm move independently of the chainstay and brake caliper, so the rear end won’t stiffen when you’re on the brakes. The other big change is the shock linkage. Instead of being fixed on one end, both ends of the shock attach to moving links, which Trek says improves small-bump performance without sacrificing that “bottomless” big-hit feel. The rocker link was overhauled too—rather than two pieces bolted together, the EVO link is a lighter, stiffer one-piece rocker that delivers twice the stiffness at half the weight.

So how does all this tech mumbo jumbo play out in the dirt? Only a suspension engineer can pinpoint exactly how ABPs and EVOs perform while you’re rattling your molars through a rock garden, but looking at the package as a whole, it’s easy to discern the different ride characteristics of this EX over its predecessor. I spent some time on a 2007 Fuel EX last summer, and then got my hands on this 2008 EX 9 in October, just in time for some burly six-hour rides on remote Appalachian trails.

Though Trek kept the same basic geometry as the old EX, the beefy, shaped tubing and stiff rocker lend the newer iteration a stability that’s sometimes lacking in other XL frames. I’m a fan of the roomy cockpit in all of the Fuel bikes, and the 14-inch BB height seemed just right to me—the bike was unflappable on fast, rugged descents, and even on notoriously off-camber and rocky West Virginia trails, I seldom smacked a pedal.

At 28.5 pounds, the EX 9 is not exceedingly agile, but it has a way of working with you, and never against you on climbs. I’ve ridden more weight-conscious 5-inch bikes that skew toward racing performance, but some lack poise when things get woolly. The EX 9 lives on the other end of the spectrum—it doesn’t float uphill, but dig in and keep the cranks moving, and it just keeps rolling through technical terrain. A couple of notes: It took some fiddling before I had the shock dialed in perfectly; check out the Trek website for setup tips. And I’d recommend ditching the stock Bontrager Jones XR tires, which I flatted several times, for something meatier. Besides that, the EX 9 is a bona fide fun hog. —KIP MIKLER

HIGHS: Highly tunable, functional front and rear shocks; it’s white!

LOWS: Wimpy tires; mysterious rear brake noises

MORE INFO: 920-478-4678; TREKBIKES.COM