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Old 09-01-2012, 10:51 AM
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2door 2door is offline
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Default Re: Is this speed possible ???

Originally Posted by shwnrttr View Post
you can get those bike speedos pretty accurate if you measure the hieght of the tire(in inches) then multiply by pi(3.14) then convert the numbers to milimeters. this would be the value you enter into the speedo. that will get you pretty close to correct. but not perfect. my tire measured 2257mm. but to get a more accurate reading i had to enter 2233mm. into the speedo.
Another method for accurate calibration is to make a mark on the front tire where it meets the floor and a corresponding mark on the floor. Roll the bike forward (must be a straight line) for one wheel revolution then mark the floor again where the tire mark is. Measure the distance from floor mark to floor mark and convert to metric if you don't have a metric tape. This is the number in milimeters that you enter into the calibration.

Example: 2073 is the ball park number most speedometers suggest for a 26" wheel. Due to differences in tires that number might not be exact. Using the method I described above will be accurate for your tire diameter.

Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"
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Old 09-01-2012, 01:16 PM
nightcruiser nightcruiser is offline
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Default Re: Is this speed possible ???

... or you can just velcro your GPS to your gas cap and take it for a ride (running on the internal battery of coarse). I had a cheapo speedo on my bike and wasn't sure it was accurate, low and behold it was dead on when I ran with my GPS in place to check it. So cheapo speedo's can be accurate. I did nothing special with mine, just set the tire size and rode...
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Old 09-02-2012, 02:03 AM
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mapbike mapbike is offline
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Default Re: Is this speed possible ???

I also checked my bike speedometers with my GPS all three of mine were with-in 1 MPH or dead on after doing as Tom has suggested above, all of mine are wireless models I ordered from main land China for just a couple bucks each, one of them has been working like a champ since 2009, so yes, the cheapo speedo's can be accurate and reliable on the MB's in my experience.

Peace, Map
I dont always ride WOT, but when I do..I do my best to keep the rubber side down..Ride safely my friends!
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