Problem with Sram BB

[bart998]

I am having a problem with my Sram Red BB and crank. I have tried different spacer combos but the spindle is either loose and has "play" or tight and drags once the left arm is mounted. Also noticed the outboard edge of the right cup is rubbing on the inside of the crank arm. Any suggestions?

[AngryScientist]

hey Bart. i've got sram cranksets on two bikes, and my experience installing them is that the retaining bolt needs to be super super tight. i dont know the exact torque spec, but its much tighter than i would have thought. perhaps if you're thinking you're too loose with one spacer combo, in reality you have to crank the bolt down a bit more?

just a thought.

[oldpotatoe]

I am having a problem with my Sram Red BB and crank. I have tried different spacer combos but the spindle is either loose and has "play" or tight and drags once the left arm is mounted. Also noticed the outboard edge of the right cup is rubbing on the inside of the crank arm. Any suggestions?

BB30 or external? Make sure the frame is prepped if external bearings.

[bart998]

BB30 or external? Make sure the frame is prepped if external bearings.


Thanks, GXP ceramic BB on a carbon frame.

[schwa86]

I had this problem. Maybe yours is the same. The SRAM instructions are wrong on their insert. They lead you to believe that you should use a spacer if your BB is 68, but you shouldn't. This causes the crank arm to rub the BB and you can't really get the bolt tightened right with a torque wrench.

See eg:http://www.bikeforums.net/archive/index.php/t-652991.html

Have had no problems since I stopped trying to use spacer...

[bart998]

Thanks. That was helpful. Guess I keep working on it because now I know I wasn't delusional.

[kgreene10]

On a related note, I have a BB90 with SRAM cranks. For two years, they never quite sat correctly. I tried countless adjustments and shops. Fairly recently, SRAM issued a new alu dust cap with a tiny modification and that made the crank perfect. Sorry for the thread drift, but I wanted to share.

[Lorenz]

Spaces or no spacer / had the same problem.

SRAM is very bad at communicating this - there are two virtualily identical instructions: ROAD is strictly 68mm and MTB is 73mm - if you 68mm on a MTB you will have to adjust this "on your own"...

Cheers, Lorenz

[Lorenz]

double post / sorry.

[bart998]

Thanks Schwa86, AngryScientist, and everybody. I thought I was going crazy because it was loose, then I'd add another spacer and it'd be too tight. I'd take one spacer out and it was still too tight. Take out that, too loose. etc. Looks like the winner is:

No spacers. Just have to work the arm down on the spindle a few times until it seats completely.

[schwa86]

Great to hear it worked, now get ridin'