I just bought a new one on eBay for $52. Anybody have any experience with the o-ring attachments? That is the only thing that worries me. The last thing I want is going over a bump and having my sensors falling off and being shredded in my spokes Zip ties seem more secure and durable in the long run for me

Also, anybody know where to buy a complete kit without the computer for a second bike? I couldn't find one anywhere and ended up shelling out $40 for my 2nd bike.

http://www.sigmasport.com/us/produkt...s_komplettset/

Just curious though, how does the computer manage to distinguish different wheel sizes?