I’m trying to use Best Bike Split to plan a race.
How do I convert the “Watts” of rolling resistance from BikeTireRollingResistance.com into a CRR value to input into BBS?
It seems like there should be a math formula for this. For example, if I know the value of my tires are 10 watts, what CRR value do I input into BRR? There are plenty of things I don’t know (e.g., my exact CDA) but I feel like I may as well directly input what I do “know.”
Their formula is quoted in the corsa Graphene 2 review:
https://www.bicyclerollingresistance.com/road-bike-reviews/vittoria-corsa-graphene2
Use the formula: **RR (watts) = CRR * speed (m/s) * load (N) **to calculate rolling resistance at a given speed and load
the standard test conditions are described in:
https://www.bicyclerollingresistance.com/the-test
Some facts about our “standard” test:
77 cm drum diameter.Standard test drum speed of 200 RPM which translates to a speed of 18 mph / 28.8 km/h.Diamond plate drum surface.42.5 kg load.Computerized measurements.Controlled temperature between 21.5-22.5 °C / 70-73 °F.
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If you scroll down on bicycle rolling resistance.com to Rolling Resistance Test Results it gives a CRR value at set tyre pressures. That said the CRR will be effected by the road surface you are riding on.
Inner TubeConti Race28 (100gr butyl)Rolling Resistance 140 psi / 9.7 BarNot Tested
CRR: Not TestedRolling Resistance 120 psi / 8.3 Bar10.0 Watts
CRR: 0.00300Rolling Resistance 100 PSI / 6.9 Bar10.7 Watts
CRR: 0.00321Rolling Resistance 80 PSI / 5.5 Bar12.1 Watts
CRR: 0.00363Rolling Resistance 60 PSI / 4.1 Bar14.2 Watts
CRR: 0.00426Use the formula: **RR (watts) = CRR * speed (m/s) * load (N) **to calculate rolling resistance at a given speed and load
Edit: Posted too slow but mine is simpler!
Awesome. Thanks! Figured it was a simple answer.