I've just installed a brand new Ultegra 6600 crank/bb on my brand new frame. Everything is fine and properly installed, but the crank doesn't rotate as freely as a square taper BB. The bike is not yet ready to be ridden waiting for some parts.

Will the bb break down?

  • Was the BB shell of the frame faced before fitting? – Emyr Jun 6 '14 at 8:47
  • Did you use a dynamometric wrench (in case this is not a press-fit bb)? – Vorac Jun 10 '14 at 11:51

Assuming you have the BB installed properly (no cross threading) it is normal to have a little bit of resistance when they are new. But honestly they don't feel as "free" as a square taper BB because of the resistance from the bearing seals.

Also, be sure to check the drive side cup of the BB every 3-6 months. If you ride in wet conditions aim more for the 3 month side. That cup has a tendency to seize up. It happens with all steel ball outboard/hollowtech BB's and the only answer is a ceramic bearing model or a Chris King BB.

  • If the bearings seize up, pop out the seal with an old blunt blade (without damaging it) and flush out with wd-40, dry and regrease thoroughly. – James Morris Jun 6 '14 at 12:45

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.