Cannondale's new Scalpel XC racer features zero-pivot swingarm
By Loz Blain
January 28, 2008
January 29, 2008 Already the dominant bike in cross-country racing, the Cannondale Scalpel has received some significant upgrades for this year's model. The most fascinating is the company's decision to do away with a chainstay pivot on the rear suspension – instead employing a unique bending carbon fiber unit that uses its designed-in flex to improve bump handling and stiffness while increasing rear suspension travel to 100mm. Combined with Cannondale's amazing single-sided Lefty fork and a host of other new developments, the new Scalpel is quite a stunning piece of engineering.
Launched in 2000, Cannondale’s Scalpel quickly cut its way through the XC World Cup rankings to become the most successful cross-country (XC) bike of its era. With countless gold medals and over 45 podium positions, at the highest level, the Scalpel has been continually tuned by the worlds best riders including Christoph Sauser, Roel Paulissen, Fredrik Kessiakof and Kashi Leuchs to help give them the winning edge.
The new 2008 Scalpel is an incremental but significant improvement on the existing bike. Rear wheel suspension travel is increased to 100mm, the bike's overall weight is 10% lighter, and stiffness is up by 15%, particularly around the crank, where Cannondale discovered that torsional flex was robbing a slight amount of pedal power from riders on the previous frame.
The rear suspension improvements have been enabled by the use of an innovative pivotless bending chainstay assembly, using precisely oriented carbon fiber construction techniques to pinpoint the location of the bend. The chainstays are then preloaded with a slight downwards bend, which dramatically improves the suspension system's ability to deal with small, quick bumps. The absence of a pivot point removes the need for bearings and other additional hardware, helping keep weight down to match the Scalpel's single-minded race focus, as well as delivering a stiffer, more efficient and durable rear triangle.
The new BB30 Hollowgram SL crankset is over 85g lighter than its predecessor and comes outfitted with ceramic bearings for maximum efficiency, making it the lightest and stiffest production crankset on the market. The new SL cranks, for example, are 25% more hollow, and optimized to spread their stress load much more evenly than the previous Hollowgram units, making them the lightest and stiffest cranks on the market.
The bike maintains the extraordinary Lefty front end, which uses a single sided air-sprung fork and a dazzling array of 88 needle bearings to provide the lightest, strongest and best handling front suspension on the market. Weighing in at 1225 grams, the Lefty Carbon Si SL DLR2 delivers 110mm of fork travel with 10-click rebound adjustment.
Both front and rear suspension can be locked out and released electronically on the go with handlebar-mounted controls, so on flat ground, no pedal power is lost to suspension travel.
These significant improvements to a bike that was already dominating in competition should see the Scalpel maintain its spot as the bike to beat in cross country racing for some time to come.