I'm switching out the bottom bracket on my singlespeed (Gunnar Ruffian) to a Truvativ Giga Pipe SL LT. Unfortunately, the instructions call for an O-ring that goes between the non-driveside cup flange and the BB shell, but I don't have said O-ring.

For those of you familiar with this BB, is this something I can easily replace? Can I get a generic one from a bike shop or hardware store? Is there a certain size I should be looking for?

I've included Truvativ's diagram below, showing the O-ring on the left adapter cup. Thanks for any help you can offer.

Nevermind. I got it figured out.

I expect the o-ring is just there to keep water and crud off the threads as the instructions say the nds cup will bottom out on the cartridge before it hits the bb shell.

I'd take the cup to any hardware or home center and find an o-ring that was a snug fit on the threads. Which is maybe what you have already done?

Yeah, I picked up a few different o-rings from Menards and found one that did the trick perfectly. Thanks.