Roll-Down Testing of Aerodynamics and Rolling Resistance

Great test of 24 road tires and feedback on Italian threading

Dear Lennard,

I have an older bike (Colnago C59 with Bora Ultra 35s)) and my buddy has a newer bike (Pinarello F10 with a deeper section carbon aero wheel set - maybe 50s)

We are the same weight.

So, if we  roll down a hill without pedaling, is it fair to assume that the comparative drift speed reflects the full package of comparative aero benefits between the two bikes and rider positions? (discounting what I assume are minor differences in bearing efficiency)  Or is this 'test' too simplistic even though on a lo

ng hill (mile) we are subjected to various different wind gusts  and that this 'test' can be repeated under different conditions. (assuming no drafting)

Jeff

Dear Jeff,

If you each roll separately down the hill, I don’t think that test can give you useful and relevant information; you need a different roll-down protocol. Timed tests of a single rider will never give the accuracy and repeatability that you need. There are simply too many variables from run to run.