Bottom bracket clicking - options?
 

I tried searching the forums but haven't been able to find an answer to this specific question.

I have an old steel frame that I upgraded to all new SRAM Rival parts last year, including the GXP aluminum bottom bracket. I get quite a bit of clicking from the bottom bracket now, especially when I push hard to go up hills or accelerate. I'm sure it's not the seat post because it happens whether I sit or stand. I'm pretty sure it's not the pedals because when I remove the BB, re-grease and re-install (to the proper torque), the clicking goes away for a short while but then starts to come back again.

I've heard that an aluminum BB with a steel frame is prone to the clicking/creaking. My question is: would it help to go with a ceramic BB instead or would that also cause clicking/creaking?

Alternatively, what kind of grease do you guys use for your BB? I've tried Phil bike grease, and have tried teflon plumber's tape instead of grease, to no avail.

Thanks!

Going to a ceramic BB wouldn't solve the problem as the interface between the BB and the frame will still be aluminum and steel. When you remove the BB do you clean the threads well before installation? Any chance the noise really is with the BB and not something to do with the fit?

Thanks ScrubJ, that's too bad about ceramic not solving the problem. Although maybe I should be glad - no need to go spend a couple hundred bucks on a new BB.

I did clean it about as well as I know how. Degreased it with alcohol, letting it soak for quite a while, then dried it out before reapplying grease and reinstalling. The BB only has about 3,000 km on it, but I guess it's possible there was something wrong with it from the beginning. But would the problem then go away for a short while after servicing it, before the creaking comes back?

The creaking is most likely due to fretting between the BB threads and the shell. There is a large amount of clearance between the threads of the BB cups and the BB-shell. This clearance allows for vertical movement of the BB cups inside the shell which leads to the creaking. The way I've solved this is to fill this gap in the threads with teflon plumbing tape.

Start with two layers of tape and feel how it spins on by hand. I've found that on some BBs, it requires 4 layers of tape. Using 3 layers of tape still caused the creaking. While 5 layers is too thick to spin on. It does require a bit of trial & error as you have to remove all the old tape and count the exact number of layers you apply, but in the end, it gives you squeak-free BB for years.


BTW - are you putting on the cranks dry or greased on the tapers? What torque are you using to tighten the crank bolts?

Danno- the SRAM Rival is a two-piece crank with the left arm held by a splined interface. I don't know if that's the source of the OP's problem.

http://ecx.images-amazon.com/images/...LL._SS400_.jpg

Ah good point. I wonder about those splined interfaces as well.

So you think the creaking might just be endemic to the splined interface itself and have nothing to do with the steel/aluminum issue?

Danno, I have tried teflon, but I didn't try adding more and more layers. I just tried one layer, and even with one it took a fair bit of force to get the BB cup screwed into the shell. But I'll take some time this weekend and try one or two more layers and see if that works. Thanks!

Mine loosens from time to time and always creaks. Just the slightest loosening will cause it and I can always tell when it needs tightened, even though I may only get an 1/8 of a turn on the wrench, it stops the creaking. I have snugged it up twice in about 400 miles. I suspose I ought to stick a torq wrench on it at some point, I may not be tightening it enough.

Hopefully when I replace it after the season, I won't have that issue.

Perhaps the bottom bracket shell needs to be refaced -- that may help prevent the BB from loosening prematurely.

Interesting idea. When you remove the BB next, check to see if there's paint on the outside faces of the BB-shell and if there's paint on the threads where the cups go. Both should be bare. Facing the BB really only needs to be done once on the initial assembly of the bike. Perhaps to scrape off paint if the frame's been repainted, but even then the paint won't affect the squareness of the BB-shell face by much.

How tight is the fit between the BB-spindle and the bearings in the BB? Were you able to slide it through by hand? Or did you have to really force it? It it went in by hand, it's way too loose and this clearance could be causing the creaks. Use a heavy-grease to assemble.

TEST

1. with the bike-stationary, sit on it and position the crankarms to be horizontal.
2. Stand up and give a little hop to load up each crankarm evenly (the crank shouldn't spin).
3. sit back down and spin the crank 180-degrees so the rear-facing crankarm faces forward and vice-versa
4. stand back up gently and give little hop to load up the crankarms again
5. did you hear a creak?

Finally got around to taking it apart again this afternoon. Cleaned it all up and wrapped the BB cup threads with teflon plumber's tape, about 3-4 times around. Put it all back together, and it's quiet as a mouse! Thanks for that suggestion, Danno.