Test: Carbon Fiber GT Fury

In 2008 at the annual Interbike tradeshow in Las Vegas, there was a buzz among those who cruised the aisles searching for groundbreaking products, and GT’s  prototype carbon fiber downhill bike was the reason for their excitement.

GT took their time developing the first production carbon fiber downhill bike frame. Prototypes were ridden and raced on World Cup and National downhill circuits for two years by the likes of Mick Hannah, Eric Carter, Marc Beaumont, Bryn Atkinson and Kevin Aiello, each offering their input on geometry tweaks, suspension tuning and handling performance. Although it has been a few years since the world first saw the bike that became known as the Fury, the result of the combined efforts of GT’s engineers and their team riders is a race-ready, head-turning downhill dragster.

As with practically any downhill bike, the Fury will be most at home at the bike park. However, at $6999, it is also designed for the dedicated racer who acknowledges the cost of elite-level componentry.

As you know by now, the Fury has a monocoque carbon fiber frame that GT claims is ten times stronger than its aluminum counterparts, with forged and machined aluminum fitments.

“I don’t look at carbon the same way I did before we started this project,” says GT’s Robert Stemen. “We’ve proven its use in this application, and it has exceeded our strength tests by huge margins.”

The new Independent Drive suspension assembly features a new link and pivot design for 8.3 inches of rear wheel travel and utilizes the RockShox Maxle rear quick-release thru-axle. The Fury uses a 1.5-inch diameter head tube and an internal FSA Orbitz headset.

The Fury’s downtube employs what GT calls their “Rockblock,” meaning an outside layer of Kevlar is the last strip put on the frame’s mold to help defend against trail debris shot from the front wheel into frame’s downtube.

The Fury is outfitted with a throng of World Cup-proven components like the RockShox Boxxer World Cup fork and Vivid 5.1 shock; Shimano Saint cranks, brakes and rear derailleur; and Funn’s direct-mount stem and Fatboy handlebar. The Shimano Dura-Ace 12-25 road cassette keeps time with the Shimano Saint 38-tooth front chainring. The drivetrain is kept in check by e.thirteen’s SRS LG chainguide.

The Fury doesn’t come stock with pedals, but our size medium test bike weighed 41 pounds with Shimano’s DX clipless pedals.
Ergonomics: Occasionally, the wrecking crew runs across test bikes that we know have spot-on geometry just by looking at them. The Fury is one of those bikes. The 65-degree head angle is sufficient for technical descending, and the 28-inch top tube is extraordinarily low for a downhill bike. The 29.5-inch-wide Funn handlebar is a welcome site in the cockpit. After setting the front and rear suspension sag at 25 percent, we were good to go.

Pedaling: The Fury is one of the strongest pedaling downhill bikes we’ve ridden. The Independent Drive suspension and RockShox Vivid 5.1 shock work together to propel the Fury rider forward with each crank rotation. Unlike with many long-travel designs, very little energy is wasted when sprinting on this race bike.
Cornering: The supple rear suspension combined with the rigidity of the RockShox Boxxer front end means the Fury holds its line on rugged, off-camber corners. The Kenda Nevegal tires are as versatile as they come and hold firm in both hardpacked and slightly loose turns.

The ultra-wide Funn Fatboy handlebar gives the rider massive amounts of leverage when trying to hold a line and greatly helps slow down steering and improve stability when changing directions over gnarly rocks and roots.

Descending: Our initial testing on the Fury took place at Bootleg Canyon in Boulder City, Nevada?a place notoriously brutal on both bike and body and ideal for long-travel rigs.

A downhill race bike needs to take to technical descents and aggressive riding like a duck takes to orange sauce?which is why we were so surprised that on our initial rides, the Fury’s Independent Drive suspension felt choppy and skipped around over unruly terrain. Being familiar with both GT’s former DHi downhill bikes and the highly rated RockShox Vivid shock, we knew something was amiss with the tuning and suspension combination.    

It turned out our test bike was equipped with the wrong version of the stock shock. RockShox offers three different tunes?A, B, and C?and our Fury was delivered with a B tune when it required the A tune. The various factory-set tunes correlate with leverage ratios for different suspension designs.

After we swapped the shock to the proper version, we were able to acknowledge the Fury’s impressive rear-end traction on technical terrain at race speed. The initial part of the rear suspension stroke isn’t as supple as other designs we’ve ridden, but once aboard and charging the trail it became more responsive. Our best analogy for the Fury’s suspension’s performance is to think of it in the manner of how a Supercross motorcycle’s suspension is tuned?very firm, compared to that of an enduro motorcycle, which feels more supple and forgiving at lower speeds over technical terrain.

Both the RockShox Boxxer World Cup fork and the Vivid shock offer low-speed compression tuning. On gnarly downhill trails requiring every bit of the Fury’s travel, we wanted to achieve maximum small-bump performance and traction, so we used just a click or two on both the fork and shock. For smoother courses with a lot of pedaling, riders may wish to add a couple more clicks of low-speed compression to the shock.

Braking: The Shimano Saint brakes and their metallic pads provide remarkable bite at the rotor and are perfect for high-speed descending. The four-piston Saints feature a reach adjustment knob, allowing you to customize the lever reach to your liking at the handlebar?an under-utilized feature that helps reduce arm pump.

The beauty of GT’s Independent Drive is that it greatly reduces both chain growth and braking forces on the rear suspension. When you’re on the binders on white-knuckle terrain, the ID suspension helps keep you in control of the Fury by allowing the rear wheel to maintain traction.

The Fury has a slick and unconventional appearance, but it is rather uncomplicated to service. The shock is easily removed with a 5-millimeter hex key, and the bolts are threaded directly into the frame, not sharp-edged shock hardware.

Downhill racers will likely swap the quick-release seatpost clamp for a bolt-on version. Ours actually broke on our third day of riding it.

You may be thinking that at 41 pounds, the Fury’s weight is average, but you can easily shed close to four pounds by going to a lighter-weight, tubeless wheelset and a titanium shock spring.

The Fury shows GT’s commitment to putting their neck on the line for the sake of innovation in performance. The carbon fiber Fury is an expensive rig. Many of GT’s competitors are offering race-ready bikes for nearly two grand less than the Fury. Our gut feeling is that GT set out to make a statement with their carbon fiber downhill rig, telling the world they mean business when it comes to advancements in frame technology. We bet there will soon be a more affordable aluminum version that’s on par with the Fury’s performance.

The Fury has a comfortable cockpit, dialed geometry, sprints extremely well under power, and is built with a component spec that has stood up to the toughest World Cup courses. However, the challenge GT faces is convincing riders to drop the extra coin (over $1000 more than leading competitors’ downhill bikes) on the Fury because it’s made from carbon fiber, despite its average weight for a downhill race bike.