| 06/25/2001 | Cannondale Begins to Ship 2002 ScalpelCannondale announced today that they have begun shipping 2002 model-year bikes equipped with their all-new Scalpel lightweight full-suspension frame. The cross-country oriented Scalpel was unveiled in March at the Sea Otter Classic, and has been raced by members of the Volvo/Cannondale team in the months since.
The Scalpel was named for its light weight, precise handling, and “cutting-edge” technology. Weighing less than five pounds (including the rear shock absorber), the Scalpel frame is nearly a full pound lighter than the Cannondale Jekyll full-suspension frame. The Scalpel also boasts 2 ½" of fully useable rear wheel travel, remote front and rear lock-out, and a cross-country-specific geometry with a relatively low, 12 ¼" bottom bracket height.
A total of four 2002 models will feature the Scalpel frame:
-The top-of-the-line Team Replica model comes with Cannondale’s weight-saving Hollowgram crankset and bottom bracket, an innovative Lefty Carbon ELO fork with electronic lock-out, Magura Marta disc brakes, UST tubeless wheels, and XTR derailleurs.
-The Scalpel 2000 has Hayes Mag disc brakes, Mavic tubeless wheels, and XT parts with an XTR rear derailleur.
-The Scalpel 1000 comes with Magura Louise disc brakes and LX parts with an XTR rear derailleur.
-The Scalpel 800 has Magura Julie disc brakes with Deore components and an XT rear derailleur.
The 2000, 1000 and 800 models all come spec’d with a HeadShok Fatty Ultra DL fork that features a weight-saving aluminum inner steerer and an on/off Damping Dial.
EPO REAR SUSPENSION
By far the Scalpel’s most notable feature is its EPO (Engineered Pivot Orientation) linkage rear suspension, and the suspension’s most innovative components are its carbon fiber chainstays. The stays have an essentially rectangular cross-section, with the major (longer) axis oriented vertically at both ends. Along the central portion of their length, the stays are somewhat flattened.
The key to the EPO’s performance is how the chainstays’ unique shape, and the careful orientation of their fibers during fabrication, force them to bend at a precise point mid-way along their length. (As opposed to other designs with flexing chainstays, where the stays bend throughout their length.) By isolating the point at which the stays bend in reality, the pivot point around which the swingarm rotates Cannondale engineers are able to dictate the performance characteristics of the rear suspension.
Before the EPO stays ever bend upward, though, they are bent downward. Preloading the Scalpel’s shock absorber also preloads the chainstays, bending them downward at the pivot so the suspension is extended an additional 1" at the rear dropouts. The natural inclination of the stays to spring back to their resting (unloaded) state functions as an integral negative spring that dramatically enhances small bump response.
Preloading the stays also moves the rear wheel’s axle to a level just below the Scalpel’s mid-stay pivot. The result is that, through the first part of its travel, the rear wheel is able to move back out of the way of impacts as it also moves upward. In the latter part of the travel the pivot is below the rear axle, eliminating chain growth, pedal feedback and bobbing.
As the swingarm goes through its travel, the suspension also morphs from using the chainstays’ decreasing negative spring (for plush initial response) to using the shock absorber’s ramping, positive air spring to add greater progressivity toward the end of its travel (to prevent harsh bottoming out).
FRONT TRIANGLE
The Scalpel’s front triangle is hand-welded, heat-treated 6061-T6 aluminum, and features Cannondale’s Power Pyramid downtube. The Power Pyramid simultaneously increases in diameter and decreases in wall thickness throughout its length. As a result, the down tube has a weight-saving thinner wall and a super-rigid, oversized profile at the bottom bracket shell to resist pedaling forces. At its upper end, the Power Pyramid has a slimmer diameter for compatibility with the head tube and a beefier wall for added strength.
One of the performance criteria specified by the Volvo/Cannondale athletes was easy portagability, so the Scalpel’s front triangle has an open, uncluttered design with all of the suspension components located aft of the seat tube. And for enhanced stand-over clearance, the Scalpel’s top tube has a downward bend just forward of the saddle – a feature that Cannondale fittingly calls the Crotch Notch.
HARDWARE
The Scalpel’s EPO suspension uses top-quality parts throughout, including teflon-impregnated brass bushings at most pivots. One exception is where the two shock links mount to the Scalpel’s seat tube. At this highly-stressed point, Cannondale engineers have opted to use extremely durable needle bearings (with a double-contact lip seal and external labyrinth seal) to eliminate flexing.
The EPO’s Fox Float RL shock absorber mounts at its lower end to a linkage axle suspended between the system’s two shock links. The linkage axle is crafted from hardened, 4130 cold-drawn nickel-plated steel, and provides a hard bearing surface for the shock bushings and high torsional stiffness between the links. At its upper end, the shock attaches near the top of the seat tube between two beefy mounting tabs. For strength and durability, the upper shock mount, the lower shock link mount, and the upper length of seat tube are all actually one forged part. (On smaller frame sizes, the seat collar is also part of this forged part.) The forging is reinforced with a V-shaped rib on the back side of the seat tube that adds significant strength with only minimal weight.
The new bike was designed with substantial input from the cross-country racers on the Volvo/Cannondale team, including two-time World Cup Champion Cadel Evans and Sydney Olympic Bronze Medalist Christoph Sauser. Evans, Sauser, and the team’s other cross-country racers will compete aboard the Scalpel at most 2001 World Cup events.www.cannondale.com
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