FlyingLaZBoy
Moderator
'16 ICE SprintX fs, '16 Rocket, '12 KHS Mocha
Posts: 5803
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Forget the tape -- find a crack, and put your valve stem right at it. Roll out straight for 4 or 5 rotations till the valve stem is at the bottom again, and mark/measure that distance using a 25' tape. If you measure with a standard tape in inches, multiply your inches by 25.4 to get mm... Then divide the distance by the number of rotations. There's your number. Four rotations would be about 20 feet, or 240 inches 240" x 25.4 = 6096 mm 6096 / 4 rotations = 1524 ****************** As an interesting variation, do this with tires fully pressurized, then repeat with pressure ~25 pounds lower. The difference between the two, divided by the first one, times 100, is the percent change in speed/distance readings due to tire pressure. A lower tire pressure will give you a "false" higher speed/distance, since the tire is moving you less far per rotation.
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