Re: Installing larger rims/tires...

[Khan Klatt <kmk@pacificrim.net>]

At 3:49 PM -0500 1/25/99, Chuck Simpson wrote:

>Does anyone running 16+ inch rims have problems?
>Or how do you get your speedometers re-calibrated?

Chuck-

You don't need to recalibrate your speedo if you don't increase the overall
diameter of wheel + tire.

When you go to 16" rims, most people keep the circumference of wheel + tire
by going to a narrower sidewall of a tire.

I saw the shadetree mechanic show too, but what they did was to put on a
tire with an equal sidewall.

Assume that your sidewall on your 15" rims is 3".
If you go to a 16" rim, you don't need a re-cal if your tires sidewall is 2".
Again, if you go to 17" rims, you don't need a re-cal if your tires are 1" sw.

If you go to 18" rims, you either need to recalibrate your speedo, or run
without tires. :)

Find a tire sizing guide, and examine it. Stock, our GLX's run 205/50 R15's.

This means that the width of the tire (from edge to edge) is 205 mm.

The height of the sidewall is 50% of the width, or 102.5mm. The width of
the rims is 15".

If you go to 16" rims, you'll need different tires, probably something like
205/40 R16's.

This means your width is still the same (no rubbing on your fender), but
the sidewall is now 82mm, on 16" rims.

Yes, the whole metric/english system mix is all F'ed up, who knows why they
still use inches in rim measurements?

-Khan
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Khan Klatt <kklatt@nw.verio.net>                                       Verio
Network Engineer                                    Bellingham Branch Office
Tel 800.591.2757 x 13                                    725 N. State Street
Fax 360.738.8315                                        Bellingham, WA 98225

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