place the magnet
 

Hi there

I also mounted a little digital speedo.
And I also lost the magnet several times because of high speed.
Now I mounted the magnet in the middle of the wheel.
see the pic

It stays in it's place even when I drive 200 + for a while.

see you
Cooshttp://forums.pelicanparts.com/uploa...1060712760.jpg

I never lost the magnet which is mounted on the rim with a small amount of bison tix. Great stuff and removable too,

Here is my set up. I figured if you don't want to lose the magnet, then mount it as close to the center of the axle as possible. With a tiny piece of double stick tape, the magnet has so far remained in place for over 15k miles. The side benefit of mounting this close to the axle is that it has less of an affect on wheel balance.

To measure curcumference, I wetted a small spot on the concrete , then rode across and past said area couple of extra tire rotations with my full weight on the bike, then took measurements.
I've compared the bicycle speedometer to the local police speed indicators, and it is spot on. The bmw speedometer reads 7 mph higher. Funny thing is both the bmw odometer and the bicycle odometer pretty much match.
tonyhttp://forums.pelicanparts.com/uploa...1060743526.jpg http://forums.pelicanparts.com/uploa...1060743554.jpg