For 2013, Indianapolis-based wheel maker Zipp updated its low-profile 202 carbon clincher, giving it the Firecrest shape already used on the company’s 303 and 404 wheels. The new 202, the company says, is ready to tackle climbs, speed through crosswinds, and stand up to the abuses of everyday riding.
The 202, the lightest of Zipp’s wheels, has been a favorite among climbers, serving as a low-profile alternative to the heavier, deeper 303 and 404. The revised 202 wheel uses Zipp's Firecrest shape, a continuous-radius design built into the 32mm-deep rim, which the company claims gives it the same aero advantage as a 66mm-deep V-shaped rim, while being less susceptible to buffeting by crosswinds.
As Zipp explains, the overall force of side winds on the front wheel can fall in front or behind the steering axis of the bike (the centerline of the head tube). This means wind makes a bike want to turn, and the farther that force is from the steering axis, the more leverage wind has, and therefore, the more difficult a bike is to control. Zipp took care in developing the Firecrest shape to center the rim’s drag. The result, as proven by the company’s Computational Fluid Dynamics (CFD) modeling, is that force is kept to within a few millimeters of the steering axis, no matter the angle of the wind. Zipp believes that it’s equally important to smooth the air passing over both ends of the wheel, so the wheel’s aerodynamics are designed to consider both the leading (front) and trailing (back) ends of the rim.
The Firecrest profile means that the rim is also wider (Zipp did not provide the exact dimensions) than previous 202s, which leads to a wider contact patch, and a corresponding decrease in tire rolling resistance. Improved carbon construction methods also help make the wheels stronger and more durable, ready for rough roads or even cyclocross.
Zipp says the 202 Firecrest is just as stiff as its 303 wheelset, but weighs 150 grams less. The set weighs 1,375 grams, making it worthy for competition in the hills, and tough enough to stand up to the spring Classics. The wheels will land in shops in October, and the wheelset will cost $2,725.