The circumference of a wheel is given by multiplying the diameter times the value for pi (3.1415).
1. A wheel with a diameter of 20" will have a circumference of 62.83"
2. A wheel with a diameter of 26" will have a circumference of 81.68"
3. A wheel with a diameter of 27" will have a circumference of 84.82"
Comparing the two larger wheels with the smaller wheel, the percent differences are +30.0% and +35%
So, those figures can be used to adjust the Speedo.
Joseph C.
tutor
Thank you for responding.
The Spedo depends on each revolution to determine the velocity. A 20" wheel will make more turns per mile than a larger wheel, so the velocity will be exaggerated.
After adjusting the Speedo to a wheel diameter of 26", the displayed velocity will be 30% less than before the adjustment.
If, as an example, the prior speed was 50mph, the speed after the adjustment will be 30% less, or 35mph.
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05/22/16
Joshua H.
Thanks for your help!!
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05/22/16
Joshua H.
05/21/16