Originally Posted by
bktourer1
I have a wired computer and bought a wireless as a backup.
Set wireless to the same diameter ( 2168 700x35 ) as the wired and logging less mileage ( 1 mile) on wireless than wired.
I usually ride the same route so I know the wired mileage is right,
Should I change the wireless diameter up or down to come close to the wired?
What is the total distance of the ride?
These work by counting wheel rotations and multiplying the number of rotations by the circumference.
If the circumference for both is set to the same number
and they are counting wheel rotations properly, they should produce the same distance.
If you are using the same circumference and getting different numbers,
then one or the other (or both) is counting rotations incorrectly.
The usual problem is magnet alignment,
Wireless can also have interference.
Digital wireless should lose rotations (yielding a number that is lower than actual) if there's a problem.
Non-digital wireless might measure spurious extra rotations.
Unless the number of dropped rotations is close to constant, changing the circumference won't help much (that isn't fixing the problem).