Lefty Speed Carbon SL: Cannondale has been preaching system integration for a long time, and this fork is proof of their commitment. The 4.3-inch-travel fork weighs under three pounds.

Cannondale's Rush platform (introduced in 2006) fits into the gap between the company's short-travel, single-purpose, cross-country race bike (the Scalpel) and their 5.5-inch-travel trailbike (the Prophet). Cannondale gambled that there were plenty of riders who wanted the responsiveness and vitality of a cross-country race bike with the forgiveness of a plush, long-legged trailbike. The gamble paid off so well that Cannondale is not merely continuing the Rush model for 2007, they have expanded the Rush offerings from seven to ten models, three of which are crafted from carbon fiber.

The Rush Carbon Team (tested here) is joined by the $5000 Rush Carbon 1 and $4500 Carbon 2. The three models share the same frame with the price (and weight) differences being determined by the component mix.

The Rush Carbons use a full monocoque front triangle that is claimed to be 10.5 ounces lighter than the alloy Rush. The design flexibility of carbon allows Cannondale to not only create a flowing beauty of a front triangle, but offer a low standover height as well. Cannondale's System Integrated (SI) Headset shaves weight by eliminating the need for cups. Bearings are pressed directly into a pre-molded headset design.

The guys at Cannondale's Connecticut headquarters were amused by all the hype bestowed on Specialized when that company introduced their own fork late in 2006. "Excuse us," said the polite Cannondale engineers, "we've been doing that for five years now." The new 4.3-inch travel Lefty Carbon SL fork comes in at a mere 2.7 pounds. The fork has size-specific compression valving and negative spring settings. Cannondale's SI stem/steerer system is integrated into the Lefty, but riders have nine sizes to choose from to attain the proper position.

ON THE STAND
While the Rush Carbon can't technically be called a "totally-new" bike (it shares its geometry and rear suspension with its aluminum brothers), one ride is all it takes to realize the Carbons operate on a different plane than the alloy Rushes. It may share many of the design features of last year's Rush, but this is a different beast on the trail.

Hammering along: Close your eyes and sit on the Carbon Team and it feels like any Rush. Start pedaling, however, and you will feel the difference between the Carbon Team and last year's Rush 3000 from the moment you start spinning. There are a few reasons. It is two pounds lighter than the '06 Rush 3000 we tested (July 2006), but the weight reduction doesn't tell the whole story. The Carbon Team feels way stiffer in the saddle. We are not talking punishment-type stiff. It is an increase in torsional stiffness that could probably be felt as easily by a beginner as a seasoned MBA wrecking crewer. It is not a subtle improvement—it is in your face.

Cornering: The same torsional rigidity that gives the Carbon Team a rocket-assisted push when hammering helps tame this quick-steering bike in the corners. Cannondale added a lot of rigidity to the front triangle (just look at the head tube), and it pays off with a bike that can stick any line you ask it to. We found ourselves hitting lines that we would have blown on a lesser bike.

Climbing: As with all good high-pivot monoshock swingarms, chain tension causes the suspension to firm up slightly when pedaling in the small chainrings. This, and the effectiveness of the Fox RP23 shock's platform, makes for an acceptable climber in standing or seated modes. The Rush's double anti-bob function is a big plus when surprised by steep climbs or step ups. The quick-steering Rush requires a light touch on the bar during climbing to avoid scissoring up the trail.

Downhills: The Carbon Team doesn't mind tough and technical descents, but riders need to make a conscious effort to keep their weight back. We felt the alloy Rush was nervous on fast descents, but the carbon has a calming effect on the Rush's personality. This is a far more comfortable Rush at speed that gives the impression of an extra inch of travel.

Braking: The Rush rider needs to concentrate on keeping his weight rearward under hard braking. Braking from a neutral position results in too much weight shifted to the front of the bike, taxing the fork and causing the steering to feel steeper. The Juicy Ultimate brakes are powerful, quiet and fade free, but did prove a little grabby at slow speeds (like on a switchback).

Jumps, big hits and drops: The Rush Carbon Team can handle anything found on a technical singletrack. If you are looking to go big enough to scare yourself, grab a Cannondale Prophet. The Rush's personality is closer to Cannondale's cross-country racers than their downhill offerings.

Component standouts: All the frame rigidity in the world is worthless if the wheels can't back it up. The Mavic/Maxxis combo has the Carbon Team's back. The new Mavic wheels and hubs mated with Maxxis Crossmark tubeless tires are a great match for the carbon frame. They roll like cross-country racers while offering plenty of bite for cornering and climbing. A very nice spec.

Cannondale uses the BB30 International Standard (an oversized bottom bracket shell) that allows for pressed-in bearings and a 30-millimeter spindle. The system saves weight by eliminating cups that would normally hold the bearings. This design may account for some of the frame's torsional rigidity.

Keep rolling: Get past the sexy looks of the Mavic CrossMax SLR UST wheelset because they are so much more than pretty. This was our first extended test of the wheels and we rode away impressed.

OBJECTION
A plate on Mavic's front hub backed out during a ride. It went unnoticed until we tried to remove the wheel. Without the cap, the bolt holding the front wheel has nothing to push against, so the wheel can't be removed. Remember, you can change a flat tire without removing the wheel, so the missing cap was only an issue during transportation.

It is a long reach to the Fox RP23 shock's ProPedal lever (by the way, we continue to love this shock, and the Carbon Team is just one more bike that it works great on).

Shifting from the granny gear to the middle ring requires soft pedaling. Shifting under torque resulted in a nasty crunch and the chain had trouble finding its way to the middle ring. Keeping an eye on the chain (making sure it was properly lubed) helped, but didn't cure the problem.

Finally, making knee contact with the lockout lever on the Lefty fork is not very hard to do when out of the saddle. The lever can't be repositioned because of clearance issues with the handlebar. You've been warned.

THE JURY RETURNS
What a difference a material can make. The carbon treatment moves the Rush off our capable-trailbike list and onto our standouts list (the price also moves it to our steep-for-a-wrecking-crew-salary list). It is faster, lighter and more forgiving than the alloy Rush. Its limited travel may put off some riders, but look past that number before you make a final decision. There is hidden travel in there somewhere. This bike's light weight and responsiveness will leave a number of longer travel trailbikes wondering what just flew past them.

Price $6499
Country of origin Taiwan
Weight 24.3 pounds
Hotline (800) 726-2453
Frame tested 18" (medium)
Bottom bracket height 12.6"
Chainstay length 16.6"
Top tube length 24"
Head angle 69°
Seat tube angle 73.5°
Standover height 29.5"
Wheelbase 43.5"
Suspension travel (front) 4.3"
Suspension travel (rear) 4.3"
Frame material Carbon/Aluminum
Fork Lefty Speed Carbon SL
Shock Fox Float RP23
Rims Mavic CrossMax SLR UST
Tires Maxxis Crossmark XC UST (2.1")
Hub Mavic CrossMax SLR
Brakes Avid Ultimate
Brake levers Avid Ultimate
Crankset Cannondale Hollowgram Si
Shifters SRAM X.0 Trigger
Front derailleur Shimano XTR
Rear derailleur SRAM X.0
Chainrings Cannondale (44/32/22)
Cassette Sram PG-990, 9-speed (11-32)
Pedals CrankBrothers Egg Beater