Find optimal tyre by surface conditions

[Bil Danielson]

Alex, what the model does not account for is the topography of the course (objective measure) and the skill of the rider (subjective assessment). If the course is 100% gravel roads with virtually no flats (like we have here in the north Georgia mtns) what happens is that control of the bike on downhills is extremely compromised as you reduce the tire width. The extreme example is running a 35mm tire at recommended bar per your model, but crashing on a steep downhill due to the tire not providing enough stability. This would apply to any cyclist to some extent, and magnified by the skill (or lack thereof) of the rider .  Thus, two additional variables to consider would be total downhill elevation adjusted for gradient and, possibly, skill level.  

Thus, by introducing a factor to account for total downhill elevation adjusted for gradient you could quickly identify those courses that, given the roughness of the surface and steepness of descents, would dictate a wider tire at lower pressure than the same course surface with little or no steep descents, 

[Coach Alex]

Bil

you are 100% correct, the calculator will only work out the theoretical best rolling resistance CRR based on combined CRR on all surfaces.

there are reasons to ride a different size and or pressure eg safety, stability, grip.

ultimately use the sheet as a heads-up but decide for yourself what is best for you.

bw

alex