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Old 06-05-2011, 11:57 AM   #7 (permalink)
IamIan
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Quote:
Originally Posted by thorpie View Post
Can anyone advise how is CRR calculated from the tire rolling resistance and the surface rolling resistance?
The Crr = RRC given from the SAE J1269 tests already includes the road surface contribution.

The RRF given from those tests already includes the road surface contribution... RRC = RRF / Load.

The tests measure the total counter force , thus they already include all sources of counter force.

I do not know of a simple conversion to accurately convert the given numbers to other road surfaces that are different from the road surface used in the testing ... you could assume it will just be the same ratio as some other test using the same tire on different surfaces ... but , I am not sure how accurate that assumption will be.
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