How to Overhaul a Bottom Bracket
How to disassemble, re-grease, reassemble and adjust a cup and cone bottom bracket.
Video updates
- 02:22 - IMPORTANT: Apply a thin layer of grease to the threads before inserting into the frame.
Today we’ll learn how to overhaul and re-grease an adjustable bottom bracket. To remove the cranks you’ll need a crank puller, a 17mm open end wrench and a large adjustable wrench. To overhaul the bottom bracket you’ll need a bottom bracket wrench or a pin spanner, a hooked lock ring wrench, and a 36mm wrench. For re-greasing the bearings you’ll need some cleaning solvent and waterproof grease, a rag, a toothbrush and a small container to clean the bearing cages.
Disassemble
Begin by removing the cranks. Watch the cotterless crank removal tutorial for a more detailed procedure. Once the cranks are removed, loosen and remove the lock ring on the non-drive or left side of the bike by turning counter-clockwise. Once the lockring is removed you should be able to easily loosen and un-thread the bearing race using either a pin spanner or a bottom bracket wrench.
Now pull the spindle and both bearing cages out of the frame. It’s important to remember which way the spindle came out, as they are directional. The drive side usually has a longer distance from the bearing race to the end of the threads. Wipe off the bearing cages, drop them into the solvent, and let them soak while you use your rag to clean the spindle and both outer bearing races.
Tighten the drive-side bearing race by turning it counter-clockwise with your 36mm wrench. Unless you are replacing the bottom bracket, there is no need to remove it.
Inspect
Shine a flashlight into your bottom bracket shell to inspect the bearing race for pitting and wear. Inspect your other bearing race and then carefully inspect the spindle. Most wear occurs on the spindle’s bearing races. If you see pitting here you should take it to your local bike shop for a replacement.
Clean
Now clean both bearing cages with a toothbrush and solvent, and then set them aside to air-dry. These should also be replaced if they are worn or have bent cages.
Grease
Apply a layer of grease on both bearing races and cages. A grease gun makes it easy to squirt grease inside the gaps between the bearings. Then place the bearing cages into both races. The rounded side of the cage should be facing down into the bearing race. Seal them in with another layer of grease.
Reassemble
Now insert the spindle the same way you removed it. Wipe off any excess grease that comes out on the spindle. Grease the threads inside the bottom bracket shell, and then slide the outer race and bearing cage onto the spindle. Thread it on all the way clockwise but don’t tighten it. Again you’ll need to wipe off excess grease.
Adjust
Thread on the lock ring finger-tight. Before adjusting the bottom bracket, first install the drive-side crank arm and tighten it as shown in the crank installation tutorial. This will help us make a proper adjustment. Now hold the inner race firmly with your wrench or spanner and tighten the lock ring. When properly adjusted the spindle should spin smoothly. If it doesn’t, you’ll have to loosen the lock ring, back off the inner race a little bit, and then tighten it again.
Check for play by placing the crank arm close the frame and pushing and pulling it against the frame. There should be no movement. If it feels loose, you’ll have to loosen the lock ring, tighten the inner race a little bit, and then tighten the lock ring again. When the adjustment is correct, install and tighten the left crank arm and you’re done!
Related Links
Recommended Tools
- Park Tool Park HCW-11 Adjustable Cup Wrench
- Hozan C-205 Lockring Tool
- Super Lube White Grease Tube
- Finish Line Grease Gun
- Shimano TL-FC10 Crank Extractor
- Park Tool CCW-5 Crank Wrench
Categories
Discuss this topic in the Bicycle Repairs and Mechanics Forum
Weak spring tension on the derailleur will result in sprockets wearing out faster
Latest post 21 hours agoOn one bike I have either the bottom of the range Shimano rear derailleur, or an imitation copy of the bottom of the range Shimano rear derailleur. The spring tension is weaker than many other rear derailleurs. The chain sags more than it should. With a derailleur like this, the chain rides up on the sprockets more than it does with a derailleur with stronger spring tension. This results in the s...
Read moreNew Stator For My Ride1up Core 5
Latest post 3 days agoHi Folks, Posted this on another forum as well. Hope to get the assistance here. I'm not a very handy ebike enthusiast. Don‘t really know the inner workings of an ebike, I just like riding them. Anyway, was riding my Core-5 that has around 1200 miles on it, and suddenly it made this strange grinding sound every time I engaged the throttle or PAS. Visited Ride1up’s support page and read...
Read moreJumps a Gear
Latest post 4 days agoWe have just changed a gear twist grip as previous broke. Have fitted a shimano 7 speed But now it jumps a gear in the middle. 1st fine 2nd fine 3rd fine But when change to 4th it jumps to the fifth sprocket so then twist gear just goes to 6th But is actually 7th on sprocket. It does the same going down gears, If you just turn twist half way through clicks 3rd / 4th it will go onto 4th. But a...
Read moreLock ring clearance
Latest post 6 days ago20220806_113536.jpg (Size: 33.21 KB / Downloads: 14) Hello To Everyone. Need a help! Is this enough clearance between the lock ring and the fork. Some bike shops say Yes some of them No. The Lock ring was tighten to the specs. I would really appreciate your opinions. Thank you...
Read moreDerailleur causing issues
Latest post 1 week agoHello there, I had managed to replace my inner tube and outer tyre successfully, however since then I have been trying to re-fit my rear tyre back onto the frame to no avail. Initially I thought the axel was at an angle. I have undone the nuts and bolts many times, rode the bike, then either the tyre starts rubbing with the frame, or the pedals become really stiff to rotate. But today I have r...
Read moreWheel not turning
Latest post 1 week agoRecently bought an Amigo scooter, I went to make a turn and the handlebar locked up, the wheel wouldn't turn and I fell off of the bike. I only had it for a day prior to that and felt it lock up a little the first day but brushed it off. do you all know what the cause could be?...
Read moreAmigo Polo Scooter
Latest post 1 week agoCan anyone help me figure out how my one day old scooter's handle bars locked up while i was making a turn ? It is the Amigo Polo and I literally had it for one day, is there a way to fix this ?...
Read moreHow do you remove a freewheel when the tool does not work?
Latest post 1 week agoI have these Chinese freewheels. On the inside are ridges which are supposed to be there so you can use the tool to remove it. With these freewheels, the ridges are very low. I have a tool, also made in China, and the ridges on the tool are also very low. So when trying to use the tool to remove the freewheel, it does not grip properly, and it can't be used to remove the freewheel. The metal on ...
Read moreOld Shimano cassette..how dismantle ?
Latest post 3 weeks ago]Hello.. First post ! In trouble already.. It's years since I last did bike maintenance and then it all seemed to easy.. I've just bought an old Dawes Shuniah mountain bike (£5) that's been very neglected. The rear hub bearing are dry and I need to repack with grease. Looks like the axle is slightly bent as well. First hurdle is the cassette removal (without special tools ) The lock nut is diff...
Read moreMake a freewheel removal tool
Latest post 4 weeks agoMake your own strong, inexpensive, freewheel removal tool, using a car wheel nut. The most common bikes with gears, use freewheels. There are other gear systems for bikes, but they are used on less bikes. The tool I will describe is for the most common type of freewheel, as shown in the picture. There are freewheels which require different tools, particularly on older bikes. free...
Read moreMontague Allston Frame Question - Dogtracking or Crabbing
Latest post 4 weeks agoMy bikes' front and rear tires are not aligned. By this I mean a straightedge held against the front or rear wheel will show an appromixately 2 inch offset as compared to the other wheel. The dealer says this is "within specification". This is the second bike with the identical situation. So the wheels are in a different track. If this were a car they would call this dogtracking or crabbing. ...
Read morePrevent breaking the axle in a freewheel hub
Latest post 4 weeks agoThe most common bikes with gears use a freewheel hub. Some bikes with gears have other types of hubs. Axles may bend and break in freewheel hubs. Heavy riders are more likely to bend and break axles than light riders. People riding on rough tracks are more likely to bend and break axles than people riding on smooth roads. Axles are more likely to bend and break in hard tails, than bikes with r...
Read moreVelowave Ranger
Latest post 1 month agoI'm getting Error Code 04H-Throttle Not Return, on the Velowave Ranger. Help please. Anyone else have this issue? Only had the bike for a week!...
Read moreMaintenance on a found bike!
Latest post 1 month agoI found a Giant manufactured (I assume based on what I have read and that it says Taiwan on the handle bar post) Schwinn Woodlands abandoned outside that I would like to fix up and use. This is some good timing as I love taking my kids for bike/walk adventures, and I am very tired of the terrible bicycle I am using now. I am fairly mechanically inclined, with replacing a turbo charger on my old TD...
Read moreRim replacement for Old Cosmos SuperCorsa
Latest post 2 months agoHey guys so I have ~50 years old Cosmos SuperCorsa and the only problem with it is that the rims are bent to the center. I want to replace them but I can't find the exact same brand at a good price. The wheels are from Campagnolo. The bike is 700c with 36 holes. The inner width is 13,5mm and the rim height is 18mm. Are the last 2 measurements not required or it should be exactly as the ones I have...
Read more
