Ron,
you haven't factored in an allowance for the flat bit at the bottom of the
tyre. It reduces the radius.
Guy
----- Original Message -----
From "Ron Corry" <Corry at iol.ie>
To: "Robert E. Shlafer" <PilotRob@webtv.net>
Cc: "Mike MacLean" <macleans@earthlink.net>; "spridgets"
<spridgets@autox.team.net>
Sent: Monday, December 15, 2003 8:20 AM
Subject: Part Three of Tyre/tire Diameters.
> Not my morning!
> Reduction in Overall Diameter below of, quote ".05%" should be ".5%", i.e
> Half of One PerCent.
> Sorry for the mistake; must remember to READ my emails BEFORE I send them
> in future!!!!!
> Ron.
> ===>
>
>
> Guys,
>
> DOH, I forgot to give you a comparison of a 155/80-13 versus a 175/70, so,
> here we go:-
>
>
> 155 x .80 = 124mm x 2 = 245mm / 25.4 = 9.76" + 13" = 22.76".
>
> From below, you can see that a 175/70 has a lesser Overall Diameter at
> 22.65".
>
> So moving from a 155/80 to a 175/70 Tyre would result in a reduction in
> Overall Diameter of just about .05%;
> i.e., what was 60 MPH on the Speedo, (and if THAT was 60 MPH on the road!)
> would now be 59.7 MPH on the road. Pretty close, I should think.
>
> Ron, in Ireland
> '59 AN5 "Oggibib"
> '64 Riley 1.5 NoNameYet
> ===================>
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