Frame Bottom Bracket compatibility
 

My bike came with a Truvativ PowerSpline BB.
http://www.sram.com/_media/images/co...line_large.gif

I would like to change out my BB to a Truvativ Giga Pipe Team SL BB or something similar
http://www.sram.com/_media/images/co...amsl_large.gif
and also a new Crankset similar to this one as well.
http://www.sram.com/_media/images/co...irex_large.gif


I am pretty sure the new BB will fit my frame which is a Spec Hardrock but I just wanted to be sure it would. I know that I need to get one that is the correct size but other than that it should be no problem, right? Also the reason I am getting this is because after my bike one month tune-up, which was over a year ago the crank arm bolts were not tightened up like they were supposed to be. I went and rode and one of the cranks arms fell off. I put it back on and tigetened it up and now every 2 months or so it works back loose and falls off. How bout that for customer service.

You are responsible for keeping bolts tight on your bike, unless you take your bike into the shop every week for a tune-up.

Anyway, having a go at shops or people is not the goal here.

That crankset is an external-BB crankset, which has its own integrated BB. The ISIS BB you've pictured is fine, but you would have to mate it with an ISIS crankset. Given that ISIS is, almost, extinct technology now, you may be better off going for an external-BB crankset and having it professionally installed.

The only compatibility issue with your frame may be the BB shell width. It is probably 68mm, but may be 73mm. I'm not familiar with the Specialized line-up. Measure it, and make sure the crankset you get is compatible with it. It should be.

- Joel

Lesson learned here, I trusted the shop to do what they were supposed to do. They failed and now I check it out all the time, out of necessity.