Here's a quick guide on how to use this section. There are a whole bunch of numbers listed for each wheel, which I've tried to explain below. In a nutshell, lower is better for all parameters. If you'd like me to clarify the meaning of some of these numbers or debate them for that matter, just write me an email or post something to the forums.
a, b: These parameters are a measure of the bearing performance. As these numbers increase, so will the drag due to bearing friction. Conceivably, these numbers could be lowered for any wheel by using high quality bearings and ensuring that they are well aligned and adjusted.
c: This component is solely due to aerodynamic drag and is a product of the wheel design. Since the power lost due to aerodynamic drag increases with w3, it's important to get this right.
I: The moment of inertia is really only important during accelerations. This parameter has absolutely no effect when travelling at a constant speed, even uphill.
P: The power required to keep a wheel moving at a constant speed is equal to the losses due to parameters a, b, and c. This is a very important performance characteristic. P30=power needed to keep the wheel at 30 km/h
|
Front Wheel |
a (x10-3) |
b (x10-4) |
c (x10-5) |
||||||
| - | custom | 2004 | 2.46 | 9.64 | 4.23 | 0.06 | 1.31 | 2.69 | 4.79 |
| 7801-SL | Shimano | 2007 | 1.8 | 4.81 | 1.8 | 0.034 | 0.62 | 1.25 | 2.19 |
| Attack | Reynolds | 2007 | 0.98 | 5.01 | 3.25 | 0.044 | 0.83 | 1.77 | 3.22 |
| Eurus | Campagnolo | 2006 | 7.59 | 5.64 | 3.38 | 0.044 | 1.06 | 2.11 | 3.69 |
| Eurus Carbon | Campagnolo | 2005 | 6.55 | 4.99 | 2.34 | 0.052 | 0.83 | 1.62 | 2.81 |
| Khamsin | Campagnolo | 2007 | 1.15 | 6.74 | 2.95 | 0.041 | 0.91 | 1.85 | 3.31 |
| Ksyrium Elite | Mavic | 2006 | 8.95 | 5.42 | 2.43 | 0.043 | 0.93 | 1.78 | 3.04 |
| Ksyrium ES | Mavic | 2006 | 13.4 | 0.99 | 4.33 | 0.039 | 1.07 | 2.14 | 3.82 |
| M28 Aero | Neuvation | 2005 | 0.77 | 1.49 | 3.62 | 0.052 | 0.67 | 1.52 | 2.88 |
| ProMotion | Kult | 2005 | 1.1 | 2.06 | 2.43 | 0.039 | 0.53 | 1.15 | 2.14 |
| Racing 5 | Fulcrum | 2006 | 4.7 | 10.1 | 3.58 | 0.047 | 1.28 | 2.56 | 4.46 |
| Scirocco | Campagnolo | 2004 | 6.22 | 3.5 | 3.53 | 0.056 | 0.92 | 1.89 | 3.39 |
| WH-540 | Shimano | 2003 | 13.6 | 4.78 | 1.49 | 0.039 | 0.87 | 1.52 | 2.45 |
| WH-6600 | Shimano | 2007 | 8.79 | 3.6 | 2.46 | 0.038 | 0.82 | 1.59 | 2.74 |
|
Rear Wheel |
a (x10-3) |
b (x10-4) |
c (x10-5) |
||||||
| 404 | Zipp | 2007 | 13.5 | 2.64 | 3.39 | 0.047 | 1.02 | 1.97 | 3.42 |
| 7801-SL | Shimano | 2007 | 6.53 | 6.53 | 2.19 | 0.036 | 0.91 | 1.74 | 2.96 |
| Ksyrium Elite | Mavic | 2006 | 6.03 | 5.26 | 2.58 | 0.049 | 0.88 | 1.72 | 3.01 |
| Ksyrium ES | Mavic | 2006 | 5.27 | 3.61 | 3.45 | 0.043 | 0.89 | 1.84 | 3.31 |
| ProMotion | Kult | 2005 | 0.63 | 2.34 | 3.08 | 0.041 | 0.64 | 1.41 | 2.63 |
| WH-540 | Shimano | 2003 | 9.42 | 2.14 | 2.36 | 0.046 | 0.73 | 1.41 | 2.45 |
| WH-6600 | Shimano | 2007 | 20.4 | 13.8 | 2.85 | 0.063 | 1.81 | 3.25 | 5.27 |
