Re: Second hand tyres, size change OK?

"·gazzafield" <·[email hidden]> wrote in message
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Quoted message said:

"MrGrumpy"
wrote in message
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Quoted message said:

Since by law a speedometer only has to be accurate to +-10% an indicated
31mph is immaterial

Your posting name suits you well, doesn't it? Under Blair's new rules
that
he's going to try and railroad in 31mph will matter. He would like to see
zero tolerance.

If you know the size of the standard tyres, and the size of the new tyres,
you should be able to figure out who faster or slower (as a percent) that
new tyres would be compared to the standard tyres. Then, you should be able
to figure out how many percent to add or subtract to speed to make the
speedometer accurate.

In the states, sometimes police put up radar guns that show drivers how
fast they are going. If you have those in England (or whereever you are),
you can get the new tyres and use this to calibrate your speedometer.

Jeff