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
Related 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
Specialized Allez Upgrade
Lastest post 3 hours agoHello! I have a 2010 Specialized Allez Sport Triple bike and I would like to upgrade to an Ultegra groupset. I am super confused with the different options for derailleur (SS Cage or GS cage/Long cage) and cassette (11-25 or 11-30). If anyone has any input or can help it would be greatly appreciated. This is the bike: Specialized Allez Sport Triple This is the groupset I would like to buy: Ult...
Read moreFront derailleur spring
Lastest post 10 hours agoWhat is the front derailleur spring supposed to be connected to? Mine is loose so there is no tension to move the derailleur back in toward the frame. The coiled spring ends in about a 1 inch hook but I do not see what it would hook on to....
Read moreRD Alignment
Lastest post 2 days agoHello guys, I want to spend my weekends learning how to's and DIYs of bike repairing. I just have this dream of starting a bike shop in the future (may after this pandemic) Do you guys have tools suggestions to buy? Please let me know. I just bought RD aligner last week bec my brother's rd tilted. Thank youuu....
Read moreCreaky crank with play and loosening
Lastest post 3 days agoCrosspost from Reddit. I have a Cannondale road bike with a BSA bottom bracket (I think; I need the Park Tool BBT-9 to remove them) and a Truvativ Elita 2-piece crankset with splines. I've been having a creaking issue on the right (drive) side for quite a while now. It happens during the bottom 1/3rd of the right-side pedal stroke. There's also a little bit of play on the right side (i.e. I can s...
Read moreFD cable pull on opposite side of frame
Lastest post 4 days agoI am building a Mongoose MTB for my wife and the front cable pull is on the opposite side of the chain and I am having a hard time finding the right Derailleur for the bike. Any suggestions?...
Read moreNeed help finding a new rear derailleur
Lastest post 1 week agoHere's my repair situation: I have a what seems like a relatively nice road bike which I found for free on the side of the road years ago. Around three years ago, while cycling, there was a stuck link in the chain that caused it to jam. As I was pedaling uphill, the force caused the metal near the mount screw on the rear derailleur to shear. I have recently wanted to repair this bike. Unfortunatel...
Read moreRemoving DT Shifter Bosses? (Not sure exactly...)
Lastest post 2 weeks agoHey Everyone, New here and I'm currently taking on a small project on converting an old-school Fuji to a SS/Fixed flipflop. Firstly I want to thank you for your time and I'm looking forward to being in this forum as a regular 😁 So im currently having trouble figuring out how to remove the DT Shimano shifters seeing as I don't want to ruin the frame, but do want a nice clean frame look. is the...
Read moreAxle is clunky/not spinning smoothly, is this an issue of bearings or cub/cone?
Lastest post 2 weeks agoI'm fairly new to bike repair aside from regular maintenance. Lately I've noticed by rear wheel has not been spinning properly--it's a Shimano 105 hub and axle. When I spin it freely on the bike, or when I spin it when the wheel is off, if feels clunky, like the axle is spinning into 'grooves' or 'notches'. I have two videos to show: On bike: https://imgur.com/a/SQX0I3P Off bike: https://imgur.c...
Read moreCant find broken cog for Next Powerclimber
Lastest post 2 weeks agoOk, so I am not real fluent with bikes, however I am attempting to repair my girlfriends Next PowerClimber 24". The cog that holds the rest of the sprockets on the rear tire is threaded to lock them in place. The cog is cracked and the threads are not holding allowing the rest of the sprockets to fall off. I have attempted to find a place to buy this broken threaded cog with no luck. I am get...
Read moreBike Chain Falling Off
Lastest post 2 weeks agoMy chain keeps falling off especially when I transition from 1st to 2nd chain ring. I also feel like I have to use a lot more pressure to shift from 1st to 2nd compared to going from 2nd to 3rd, which just might be me but I thought it was relevant to include. I am not super mechanically inclined so I can't diagnose an issue on my bike like this. Can you please tell me whats the issue and maybe how...
Read moreCassette compatibility question
Lastest post 2 weeks agoA short questions for those knowledgeable. I currently have on my bike a Shimano HG50-11-36t 10 speed cassette. Would the HG81-11-36t 10 speed be a direct replacement or will I encounter problems?...
Read morePodcasts with bike mechanics
Lastest post 2 weeks agoHello everyone. Are there any podcasts about cycling and more specifically bike mechanics? I have been learning more about bike repairs recently and would love to hear tricks from guys with know-how; need something to listen to during the work....
Read moreTire and Rim sizes
Lastest post 3 weeks agoI was looking into wheels, just for the heck of it, and something is confusing me. I have a cruiser. The tires are 26" x 2.125" (57 x 559) The rim is 1.25". Cruiser wheels, online, are 1.75" The difference between a 1.75" cruiser rim, and the 1.25" rims I have, is approximately half-inch. I bought the bike, new, from a bike shop, and bought white wall cruiser tires for it. It had wide tires o...
Read moreTools for bottom bracket on 1970s Sekine
Lastest post 3 weeks agoHi folks! I was directed here by the folks over at r/bikewrench as I hear you are a helpful lot! I have a beautiful old Sekine which I think after a little research is a SHC 271 from the mid seventies. Unfortunately I was in a pretty nasty accident last year and it was out of commission for a while. I was using it indoors on my trainer and slowly going about repairs, getting it road ready again wh...
Read moreReplacing a 7-speed freewheel with a 9-speed?
Lastest post 3 weeks agoIs that possible without switching out the hub, and is that possible at all? I have a base shimano groupset and I'm in the process of upgrading everything (I'm switching out the crappy tourney der for altus 9-speed, cables etc), and I would really rather switch out my freewheel for a 9-speeder also. Do you think it's achievable?...
Read more
