08-02-2021, 08:57 PM
(08-02-2021, 05:11 AM)Whoops_imp Wrote:(07-31-2021, 06:49 PM)Tev62_imp Wrote:(07-30-2021, 09:07 PM)Cormanus_imp Wrote: That makes sense, Tev62. The issue here is whether the profile of the OEM 140/70 and the 160/60 result in different diameters. As I recall, they don’t so there should be no speedo variation other than that you describe.
Yep, I get what you are saying, like for like there should be very little difference in the aspect ratio, 2mm is the only difference there, minimal impact.
60% of 160 = 96 and 70% of 140 = 98
Yep, I get what you are saying, like for like there should be very little difference in the aspect ratio, 2mm is the only difference there, minimal impact.
60% of 160 = 96 and 70% of 140 = 98
At the risk of sounding like a mechanical idiot, I was curious how the odometer calculates mileage. In other words, is it based on tire revolutions (i.e. diameter) or does it work off engine revolutions? Just wondering if a different tire size could potentially cause miles to accumulate faster or slower as a result of non-OEM tire sizes.
On the older bikes, like my Daytona, it is taken off a mechanical drive on the end of the front wheel axle. One newer bikes it is often electrically taken off a sensor from a rotating shaft in the gearbox. Changing the tyre would affect both though. Image the tread wearing 5mm, that is an overall decrease in diameter of 1cm. With simplistic maths and assuming the tyre profile is perfect, a complete revolution of the tyre new vs old would present a difference in distance of just under 4.4%. The Odometer didn't know you changed your tyre. So for the same engine revs you actually end up travelling slower as your tyre wears.