Well I will tell you which one not to buy....



Bell 15 Function Wireless Speedometer

I bought this one and it sucks. Perhaps it is just the geometry of my bike - the distance between my forks and my wheel... I dunno.

It works fine at slower speeds, but if I get over 15 mph it doesn't register my speed. I have tinkered with it dozens of times. Minute adjustments in the spacing, various mounting positions and heights, etc. Nothing I do fixes the problem. I even thought about writing Bell about it. Perhaps others have had better experiences with this particular model. I will be watching this thread closely.