Thread: Bigger Tires = New Tunes?
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Old Tue, June 14th, 2011, 01:44 PM
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Originally Posted by bikerfuzz View Post
Ok. I'm going to try. But why the range ? Is it to get as close to actually displayed speed?
I'm giving you a "range" as boundaries on the value I think you should use. Different tires will exhibit a different amount of "squish" under loading due to internal construction. And the inflation pressure you use will also effect the amount of squish you experience, as does the aspect ratio of the tire.

All in all, you're going to be VERY close with the middle value on either of those ranges, depending on the tire you mount. If you want to really "nail" it, you're going to have to adjust to make the Gryphon displayed speed match a GPS stabilized speed (near 70 mph is best), or, get your odometer to match a known distance driven, the longer the better (like about 100.0 miles).

The dashboard speedo will generally read about 2-3 mph faster than your true speed when everything is set right, but the odometer will be correct.

- Jack