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Old 06-03-2008, 12:22 AM   #63 (permalink)
mattW
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Join Date: Jan 2008
Location: Sydney, Australia
Posts: 76

Piaggio Fly 150 - '10 Piaggio Fly 150
90 day: 64.8 mpg (US)
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But RR is still proportional to velocity, so higher speeds means more RR losses. At 40mph RR is probably half your FE so a 10-13% gain is likely to be a 5-6% mpg increase, still very much worth it.

This thread is proving very inconclusive, we haven't seen why:
  • Higher pressure means it is more likely to have tyre failure? we've yet to see that higher pressure increases tyre stress (since it means less deformation), obviously extremely high pressures beyond sidewall. Though we have seen that the stems may be a problem.
  • Higher pressure reduces traction? since friction is proportional to the force and the coefficient of friction, not area. I have yet to see why contact patch makes a difference.
  • Higher pressures i.e. 10% over sidewall are dangerous? in light of the above two points.
So does anyone have anything concrete about why higher pressures are dangerous or is it all just a gut feeling? I'm welcome to being wrong, I just need to be convinced and I haven't been yet...
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