creaking bottom bracket
 

i've heard the expression used a lot but never experienced myself until now. or at least I think I'm experiencing it. my bike is making a noise that sounds like bedsprings when I stand up on the pedals and start to get after it. it's fairly embarassingly loud. fortunately, I just bought a new aerozine cermaic bottom bracket because i got it on closeout for $25. Before I go ahead and install, I just want to get a better idea if that is definately my problem. What exactly causes creaking? is it just bearings worn out or lube dried up?

BTW we are talking about an ultegra 6600 series crank/bb

Before replacing your bottom bracket with a new one, I'd remove the crank and check the bearings by hand. If they feel smooth, remove the cups, grease the threads, then torque to spec. Do the same with the crank arms, installing per Shimano's instructions. If the creak remains, there are a number of other causes for creaks in addition to bottom brackets. Visit http://www.sheldonbrown.com/creaks.html to learn more.

The Hollowtech II style cranksets need to have the spindles greased where they contact the bearing cups. If this wasn't done, or not enought grease used, it will lead to creaking. Noises can come from many places and still sound like they are from the BB. Only way to tell is tackle them one at a time till the creak is gone.

can i get the crank arm off without taking out that little cap? i forgot that the tool i have doesn't have that on the other side. I know it has to do with bearing adjustment but I'm just wondering if I can get it off, check the greasing of everything and install new bb then go to lbs and adjust that cap if needed.

No, that cap preloads the bearings by threading into the spindle and pulling the non-drive side arm onto the spindle. That cap likely is not torqued all that tight so you may be able to use a big flat blade screw driver to unscrew it. Don't blame me if you damage it doing that though :)

thats what i thought. I remember installing it and putting it in their finger tight and not really knowing what it was for. I'll swing by my bike shop and get the right tool for it.

the preload cap doesn't need to be really tight. finger tight is good enough.

I'm an idiot, it wasn't the bb. I bought new titanium skewers. something about how I closed the rear was making the bike creak. changed my bb for nothing! oh well. now I got some ceramic bearings in there. I bought the crank used so who knows how much life that bb had in it.