Originally Posted by
pdlamb
I wonder, was this model ever validated against experiment, or is this one of those "assume a spherical cow" type of homework problems that made it into a book?
The model is combination of basic physics and empirical models for brake/rim cooling, so fairly a sophisticated step up from a spherical cow. The model depends on your components, but Wilson is fairly conservative. The terminal velocity chart does not need brake/rim data and is a more straightforward application of physics. Wilson is a well-known expert on bicycle physics and especially HPV. If you are fascinated with bicycles, the whole book is a good read. The calculation for the amount of energy to dissipate when braking to a stop for a specific: speed, slope, mass, front cross sectional area, etc, is a homework problem....56 kJ for us on a tandem, @ 45 mph on a 10% slope. Using the heat capacity of our rims gives a 50C increase over ambient...so about 75C... which you can touch for a few second without much pain, which we have done, so kind of tested
