Troubleshooting: Fixing a Noisy Bottom Bracket
The bottom bracket is the important link that runs through your bike to connect the cranks. For a quiet, efficient ride; this needs to be lubricated and free of grime.
Being close to the road or trail surface, debris flings itself into the space between your chain ring and the frame and eventually, dirt and grit will find its way into the bearings and create all sorts of nasty noises while you ride.
It’s important to remember that bottom bracket squeaks have nothing to do with the age of the bike. Sometimes, even when a bike is new from the factory, the bottom bracket isn’t tight and it creaks. Other times, it's not the bottom bracket at all.
Most surprisingly, what often sounds like a bottom bracket creak is actually something else. Most of the time, the true cause is a loose chainring bolt—tighten them up and that’ll quiet most creaks. After you check the chainring bolts and if you still hear the noise, look at your pedals, crank bolts, seatpost, and seat. By checking these first, you’ll save an hour of digging into your bottom bracket.
Step 1: Tighten everything except the Bottom Bracket
Chainring bolts: Tighten with a 5mm hex wrench and chainring nut wrench.
Pedals: Lube all the points where your cleats make contact with the pedals. Also, remove them from the crank arm with a pedal wrench, then grease the threads and reinstall.
Crank bolts: If your cranks move side to side more than 1/16 of an inch, you’ve found the likely creak source. Remove each bolt with an 8mm hex wrench or 14mm socket wrench, then grease and retighten them.
Seatpost: Remove and grease. Corrosion can form between the seatpost and frame, making a clicking sound. If an ungreased seatpost stays in the frame too long, it’ll become stuck, so make sure you do this every so often.
Seat: Tighten the seat binder bolt and grease the seat rails and clamp bolts. The seat may be far away from the bottom bracket, but the noise can transfer through the bike.
Step 2: Repair the Bottom Bracket
Still squeaky? If you've checked the above, and you still hear a persistent creaking, it's time to work on the bottom bracket. Keep in mind, it's important to use the correct tools (as outlined below). Trying to make do with common tools like locking pliers, slip-jaw pliers, and adjustable wrenches can end up stripping your bottom bracket and do more harm than good. Find the bracket you have, then follow the steps to fix it:
Ball-Bearing Bottom Brackets: Loosen the lock ring on the bottom bracket with a lock ring tool. With a pin spanner, turn the adjustable cup clockwise until there’s no more play, but no binding in the bearings. Tighten the lock ring down to set the adjustment in place. If there’s still creaking, replace the bearings. Also, inspect the race, where the ball bearings sit, for corrosion or other damage (known as "pits")—you’ll need a new bottom bracket if you find any.
Cartridge and External Bearing Bottom Brackets: Remove this bracket with a sealed cartridge bottom bracket tool or external bearing bottom bracket tool. Clean thoroughly, then re-grease the threads on the frame and bottom bracket. For stubborn cartridge bottom bracket squeaks, use Teflon tape on the threads. Then, reinstall, putting a drop of Green Loctite on the threads. If the bearings are crunchy or there is a wobble once installed, this will need to be replaced as the unit has worn out.
Press Fit Bottom Brackets: Press fit bottom brackets are trickier to service. You’ll need the right removal too, and then you’ll need a quality bearing press tool to reinstall it. Given how many times you’ll likely need to work on your bottom bracket (not often), you may be better off bringing your bike to your local bike shop. Press fit bottom brackets aren’t designed to be reused after being removed, so you’ll need a fresh one. Also, you'll need to apply press fit retaining compound before installing it.
Other Bike Noises
Chipped paint on the threads or the face where the frame and bottom bracket meet can also cause noise. To fix it, the bottom bracket should be faced with a facing tool. Or, in a pinch, remove remaining paint with a razor. Just beware, a slip of the razor means a frame gouge, and possible frame-threatening damage, so you have to be extra careful.
You can also check to see if the noise is coming from your headset or stem by applying force to your handlebar and rocking it back and forth. If yes, disassemble both, clean, and then regrease.