Pista truvativ isis BB rubber o ring
 

there was a thin rubber o ring on the non drive side of my 04 bianchi pista's BB. since the BB doesn't bottom out on the frame, i assume the o rings to keep out gunk. mine just broke and fell off. anyone know if it's a crucial seal or more of a cosmetic deal? i can probably find one the same size at the hardware store but it seems like a bit of a cosmetic thing. any thoughts?

well you should have it, it does help keep out crap. Its worth the trip to the hardware store+50 cents

Pull the crank and look in there. If you can see into the BB, replace the O-ring. I would just get one from the Hardware store altho you could go to a hydraulic shop and get a Viton O-ring, exspensive but super tough.

Well if it fell out, then it probably wasn't doing too good of a job to begin with. I have heard that the stock BB on the pista is crap, so the bb will probably wear out/need replacement soon. You are in cali, right? I think a BB without a seal would be a bigger problem somewhere like boston, where the roads are wet, snowy, salty and sandy.

sweet
thanks
i'll go hunt something down tomorrow.