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Is there any point varying CRR with temperature?

Posted: Thu Sep 19, 2019 6:33 am
by EHB
This is actually something I came across ages ago when reading on rolling resistance in rain, but forgot. Essentially, at least in bigger tyres, a small amount of water decreased rolling resistance, but more increased it (assuming road temperature was not changed by the rain). They had to keep temperature the same as it can have quite a big effect.

Essentially, as rain has a biphasic effect on CRR I couldn’t see how you could possibly adjust for it. Temperature though… obviously you know device temperature, not road or tyre, which makes it harder, but would it make any sense to slightly adjust it so that someone cycling in 5°C got a different value to someone in 30°C? Or after tyres have warmed up reduce it a bit…

Maybe, it is only a small component and you don’t accurately know tyre/road temperatures, but I guess it wouldn’t be hard to adjust it slightly as you already know ambient temperature.

Re: Is there any point varying CRR with temperature?

Posted: Thu Sep 19, 2019 3:12 pm
by Velocomp
Do you have any data showing the relationship of Crr to temperature? It seems like this would be a very minor difference...

Re: Is there any point varying CRR with temperature?

Posted: Thu Sep 26, 2019 8:26 am
by EHB
No, but I never looked for it. Temperature seemed important when I looked for the effect of rain though & the method of testing for tyre rolling resistance almost always keeps it the same. I would bet some of these tyre testing labs have tested for a temperature effect, but not published it & just thought ‘better keep it the same’.

Re: Is there any point varying CRR with temperature?

Posted: Thu Sep 26, 2019 8:35 am
by EHB
There’s stuff for big tyres that’s quite easy to find. For example: https://www.researchgate.net/publicatio ... resistance

Not seen anything on bike tyres though.