| Crr and CdA look-up values: * |
| Tires |
Crr - Rolling
Resistance |
| touring tire |
0.0075 |
| 406mm Conti GP |
0.0072 |
| 406mm Tioga Comp Pool |
0.0071 |
| narrow racing tire |
0.006 |
| semi-wide high-pressure slick |
0.0055 |
| 700C Conti GP 3000 Silica |
0.0055 |
| wide hp slick |
0.005 |
| 406mm Schwalbe Stelvio |
0.0045 |
| Rinkowsky |
0.003 |
| Michelin Ecorun |
0.0028 |
|
| Vehicle |
CdA
Values |
Bike+Rider
in kilos |
| Barracuda |
0.055 |
106 |
| Gold Rush |
0.0465 |
80 |
| White Hawk |
0.031 |
|
| Cuda-W |
0.030 |
81 |
| Bean II |
0.0289 |
98 |
| Cutting Edge |
0.0286 |
96 |
| Cheetah |
0.0278 |
93 |
| M5 #8 fairing |
0.0255 |
|
| Varna Diablo |
0.02 |
100 |
| Virtual Edge |
0.011 |
|
| DF Standard bike |
0.68 |
|
| DF Mountain bike |
0.50 |
|
| DF Racing bike (hands on top of bars) |
0.51 |
|
| DF Racing bike (racing position) |
0.38 |
|
| DF Racing bike (using aerobars & disk wheels) |
0.23 |
|
| Easy Racer (no fairing) |
0.27 |
|
|
|
Notes:
- Calculated bike CdA varies with bike type, tire type, rider weight, and rider height.
- All Bike CdAs assume use of a rear wheel disk.
- Crr values should be an average of front and rear tire Crr
values.
- A negative slope is downhill (example: Battle Mountain run is -0.06% or -1.19 degrees)
- Note that the Battle Mountain course has a 5.5 mile run up, so peak velocities at distances over 5.5 miles are unattainable.
- Wheel weight is total rotational mass, typically around 90% of wheel weight for a spoked wheel and nearer to 75% for a disk wheel.
- Bike weight is total vehicle weight including wheels.
- * Crr and CdA values were gathered from a variety of locations,
and some values may be only rough estimations.
- A value of "0" may be used for power with a negative slope to simulate "coast down" testing.
|
Credits:
This web page would not have been possible
without the help of Gerrit Govaerts. Gerrit
worked with Walter Zorn to create this Excel spreadsheet from
which the equations used in the calculations on this page were taken, and was instrumental in
my understanding them enough to create this page. Check out
Walter Zorn's web site for more HPV simulation tools.
|
Disclaimer:
Gerrit notes "I firmly believe that sometimes an inacurate (and that will always be
the case to some extent) math model is better than none at all, but I also
understand that it can easily be abused if stretched beyond it's validity.
You are all advised to use it wisely and interpret the results!"
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Update history:
03/12/02 - V1.0 - V1.04 Tweaked user interface and added features.
03/29/02 - V1.05 Updated to use Java based plotting util.
04/07/02 - V1.1 Updataed calculations based on feedback from Charlie Ollinger, and Gerrit Govaerts updated simulation spreadsheet. It now takes a bit longer to get to terminal velocity.
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