How to Adjust a Bottom Bracket

Most recently manufactured bikes have cartridge-style bottom brackets that need no adjustment - if they develop play, it signals that they may be damaged or worn out. Here are instructions for adjusting the cup-and-cone-style bottom brackets found on most bikes built before the mid-1990s.

Difficulty:

Moderately challenging

Instructions

Things You'll Need

• Bike Grease
• Bike Repair Stands
• Bike Tools

1. Assemble the proper tools. For a cup-and-cone-style bottom bracket, you'll probably need a pin spanner and a lock ring spanner. If you're unsure, check with your local bike shop.

2. Place your bike in a bike stand. This adjustment can be made without a stand, but using a stand makes it much easier.

3. Prepare to loosen the lock ring - if you see corrosion, spray the threads with a penetrating lubricant and leave it for a while before going any further.

4. Go to the left side (or non-drive side) of the bike. Place the lock ring spanner on the lock ring. Be sure they're a good match and a snug fit.

5. Loosen the lock ring. This may take a decent amount of effort. Be careful not to skin your knuckles while turning the spanner.

6. Fit the pin spanner in the slots or holes of the adjustable cup. Tighten or loosen the adjustable cup as needed - you want the spindle to turn smoothly, with no play.

7. While still holding the pin spanner in place, carefully tighten the lock ring back down with the lock ring spanner. Before you tighten it all the way, check your adjustment once more.

Tips & Warnings

• You should be able to adjust the bottom bracket without removing the cranks. If not, see "How to Remove Bike Cranks."

• If your bottom bracket hasn't been touched in a while, you may want to loosen the lock ring and grease the threads before you retighten it.