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Old 07-31-2010, 01:40 PM
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Derks420 Derks420 is offline
Motorized Bicycle Elite Member
Join Date: May 2010
Location: Central New Jersey
Posts: 114
Default How to Calibrate your Speedo Correctly

Hey guys, I see alot of people making speed claims that are CRAZY! I am positive that may have not set up their speedo right. Here is the best way to find the size of your tire.
1. Take a piece of rope and tape the end on the tire.
2. Place tape every 8 to 10 inches until you have wrapped the ENTIRE TIRE (circumferance) once.
3. Measure the length of the string in inches.
4. Multiply your length by 25.4 ( 25.4mm=1 inch)
5. When you program your speedo, put the number that you got in as the wheel size in mm.

My tire is 77 inches in circumferance. So I multiply 77x54.4 which is 1955.8mm. When I programed my speedo, I put it in as 1956. Now acurate within 1/2 mph.

Good Luck
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