Replace or clean your Hollowtech II Bottom Bracket

Replace or clean your Hollowtech II Bottom Bracket

While summer road miles can keep a bottom bracket singing for months on end, if you venture off the blacktop onto the dustier, muddier trails your BB is going to start kicking up a fuss more regularly. Fortunately they have a useful tendency to become noisy when they need a bit of T.L.C., characterised by a creaking or clicking noise in time with each pedal stroke and potentially louder on one side. When this happens there’s no need to panic, just crack open the toolbox and get to work.

Remove the preload cap

Firstly you’re going to need to remove the cranks.  Loosen the two bolts at the axle end of the left hand crank. Unscrew the non drive side retaining cap and place it somewhere safe. It’s easy to lose, so remember where you’ve put it  Finally, flip the safety clip out from the split and the left crank should slide right off. You may need to persuade it gently.

Undo the crank arm bolts

Now the drive side and axle should also slide right out, revealing your bottom bracket.
 Arm removed

Give it a visual inspection and spin the bearings by hand. If they feel gravelly and jam easily it’s time to replace the unit, but if they still spin relatively happily then just follow the steps for removal, but after cleaning it up you can simply pop it back in.

Use a BB wrench to remove BB

To remove the BB simply slide the bottom bracket wrench over the cups so the splines mesh nicely and apply some leverage. The thing to remember here is the drive side is reverse threaded and so will loosen clockwise, while the non drive side is normally threaded. If it doesn't budge make sure you’re not tightening it up by accident (this happens to everyone at least once).

BB removed

Once it’s out give the threads a good clean and regrease before installing a new unit or reinstalling the old one.

BB cup

Reverse the process, remembering to clean and regrease the axle and tighten the crank bolts to the correct torque too (13Nm)and you’re good to go ride again in blissful silence.

See all of our BB and Crank tools here.