Subject: RE: Wheel circumference help!!! The circumference of a 650x23 wheel should be 1938mm
The calculations looks like this:
Rim, 571mm (ISO nominal )
Tire, 23mm
Total wheel diameter, 617 (571+23+23 ) times Pi, equlas 1938.36mm
There's something obviously wrong with your Timex... have you tried calling (or email ) Timex customer service? A GPS unit should not be off much at all (you will have an error margin as if you go under tree cover, underpasses, etc. basically anywhere where you lose the GPS signal, the unit will calculate the distance based upon last known location, first new location and the average speed you traveled before signal was lost; obviously this will be wrong, but usually only by a small margin ) |