I just got a $25 bike computer from REI. I have a question about installation. Does it matter whether the sensor/magnet is mounted close to the outer diameter of the rim or closer to the axle? The installation instructions show it being mounted all the way to the outer edge of the rim. If I do that, the magnet does not pass close enough to the sensor to get a signal. I had to move the everything very close to the axle. My guess is that it won't make a difference, but I figured I would check with you guys to make sure.

Thanks

There will be no difference in reading. The only significant note is that closer to the rim the motion is faster than closer to the axle so losing the magnet if not mounted properly is much easier.