Re: Why I don't trust mechanical speedometers.
the conversion is easy enough and i prefer metric anyway. what i mean is what is correction factor between the speed displayed on the speedometer vs actual speed? if theyre designed to be used with both 26" and 27", then its gotta be calibrated somewhere in the middle. on a 26" tire displayed speed would be a little faster than actual speed, while on a 27" tire displayed speed is a little slower than actual speed. i want to know how much its off