05-28-2014, 02:27 AM
(05-28-2014, 12:15 AM)Ridem32_imp Wrote: The new cars & trucks run the speedo off of the Trans speed sensor so if you change tires it does throw the speedo off. Older bikes that used cables on the front wheel if you changed to a smaller tire it would make the gear spin faster throwing the speedo off. But reading off of the wheel it self I don't see where it would throw off the speedo no matter what size tire you run. But again I might be wrong!
Never think about the rim diameter, but rather the diameter of the tire, or more importantly the revolutions per mile. You can have 2 tires that are "the same size" but list different revolutions per mile. Those little differences add up and don't only add up to speedometer error, but to odometer error as well.