Originally Posted by
StephenH
If it's working at all, it shouldn't much matter where the magnet goes. If you get it set wrong where picks up erratically, it might throw the distance off, but it's also going to be showing zero mph part of the time, too.
If it skips a few counts here and there it wont show 0. Most of these devices average a few counts. I recall the cateye I had when it was missing counts would do something like reading ~22mph, the drop to ~17mph, then pop back up.