Our $8000 size medium Pro Caliber 9.9 29er test bike weighed 19.8 pounds out of the box, and came draped with top-of-the-line Shimano XTR components.

Our $8000 size medium Pro Caliber 9.9 29er test bike weighed 19.8 pounds out of the box, and came draped with top-of-the-line Shimano XTR components (click to enlarge).​

We got our first look at Trek's innovative Pro Caliber cross-country bike at a grand launch event back in early July. Since then our ace XC race bike tester has spent some intimate time aboard the bike and been equally impressed with this race-ready rocket.

With dual suspension XC racing rigs becoming lighter, it seemed the need for a traditional cross-country hardtail would fade the way of V brakes and tubed tires. Even on the ultra-competitive World Cup circuit, races are being won on full squish bikes. But Trek isn't giving up on the rigid rear category just yet. Earlier this year it launched the Stache, a hardtail with plus-size wheels. Now comes the Pro Caliber, which has all the bells and whistles to eek out every possible speed advantage.

We were able to sit and spin more thanks to the innovative Isospeed decoupler.

Our tester was able to sit and spin more thanks to the innovative Isospeed decoupler (click to enlarge).​

Our $8000 size medium Pro Caliber 9.9 29er test bike weighed just 19.8 pounds out of the box, and came draped with top-of-the-line Shimano XTR components. But what really impressed was the Isospeed decoupler, which allows the seat tube to move independently of the connection between the seatstay and the top tube, adding a small but detectable amount of ride smoothing compliance, traction and control, without weight penalty or loss of pedal efficiency.

technology is a natural fit for mountain bikes, allowing riders to deliver pedaling power on rough, choppy trail. Here's an explanation of how it works on the Domane road bike.

It's technology that originated with Trek's Domane road bike endurance line, then moved over to the Boone for cyclocross. Now mountain bikers get to reap the rewards.

Continue to page 2 for more on the Trek Pro Caliber 9.9, including first ride impressions »

On descents, the bike soaked up small chop well, but big hits still felt like big hits.

On descents, the bike soaked up small chop well, but big hits still felt like big hits (click to enlarge).​

Does the Pro Caliber still ride like a hardtail? The short answer, according to our tester, is yes. "You still have to pick cleaner lines than you would on a full suspension bike," he said. "But the Isospeed decoupler does take some of the edge off, especially on small bumps. Bigger bumps quickly remind you you're still on a hardtail, though."

The rest of the package is equally alluring. The DT Swiss XMC1200 Carbon wheels are wrapped with Bontrager XR1 Team Issue tubeless ready 29x2.0 tires, and take advantage of the new Boost 148/110 hub standard. The 100mm RockShox RS1 fork is buttery smooth. And the full Shimano XTR 1x drivetrain is crisp and precise, with a 32t chainring combined with an 11-40 cassette to give most racers ample gear choice. Shimano XTR brakes and various other carbon bling, including Bontrager XXX OCLV Carbon stem and bars, will make any weight weenie drool. There's really nothing to upgrade here - as should be the case when you drop eight large on a bike.

Bontrager XXX OCLV Carbon stem and bars will make any weight weenie drool.

Bontrager XXX OCLV Carbon stem and bars will make any weight weenie drool (click to enlarge).​

First Ride Impressions

Everything about this bike screams speed and that was proven out on the trail, according to our tester. "Small bumps weren't as sharp as on a traditional hardtail, meaning I was able to sit and spin more than on other hardtails," he reported. "Clearly this would be a great bike for cross-country courses that aren't super technical. Think Leadville 100 and you're on the right track. On more burly courses, big bumps will still beat you up."

Bottom line, if you spend most of your time on rough trails, the Trek Pro Caliber 9.9 is not the ideal one-bike quiver. But if your backyard trails are smooth and fast, this bike will likely make you faster. And if you're looking for a hardtail XC race bike, you'd be hard pressed to find a better option, no upgrades required.

For more info, please visit www.trekbikes.com