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
Derailleur moves the chain but won't stay in gear
Latest post 2 days agoHi, I have an older road bike. It's a 12 speed with the gear shift on the lower bar. The rear derailleur seems to work, that is it shift from the small sprocket to the largest, but it will not stay in anything beyond the the small one. I have replaced the cable and adjusted the high/low as in the video (thanks) but nothing is working, it will not stay in any other gears. ...
Read moreSchwinn Meridan Project
Latest post 4 days agoOk I need to know if this is even possible? I noticed on other sites there are 6speed and 7 speed Adult tricycles. I was pondering the idea of modifying a Schwinn Meridian 2008 model into maybe a 6speed. Before I go any further is that even possible without getting into major work? If so, then what about expanding that idea into a 12speed by swapping out its current crank with an older Schwinn 1...
Read moreBrake/hub issue
Latest post 5 days agoWhat causes the brakes to lock-up i have only rear foot brake on my cruiser im sure it has to do with the hub but was wondering if its an ez fix or major overhaul?...
Read moreDefective tire causing flats?
Latest post 1 week agoHello, As some of you know, I ride a fat bike everywhere, even for my bikepacking. Over the years, I've noticed that the same tire has been getting a lot of flats. Initially, I didn't think much of it, but this time, I found two tiny steel pin-like structures that were embedded strongly into the tire. I had to use pliers to pull them out, and they almost look like the thread of wires one sees wh...
Read moreModern rims crack at spoke holes
Latest post 3 weeks agoRecently, I was in one of the local bike shops. Someone had brought a bike back to have the back wheel re-trued. There were actually cracks in the rim, originating from the spoke holes. I have had the same problem with my bike. In past decades you could buy a bike, and the wheels were strong. With modern rims, the aluminum is getting thinner and thinner. Now the rims crack. With heavy riders, a...
Read moremeridian trike rear axle lubrication
Latest post 3 weeks agogood afternoon, i have spent the last week cleaning and changing parts on my old 2009 Schwinn Meridian Trike . The rear axle is in need of lubrication. Where is this done? do I just remove the axle retention nuts on each side and lube the bearings? What is a good brand of bearing grease available at Oreilleys? Thank you...
Read moreHow to refurbish a bicycle 101
Latest post 4 weeks agoI thought I would do a thread about how to do a quality refurbish on a bicycle that will be a good user trouble free for quite a while. The scope of this refurb will not contain content about dealing with battle scars it may have endured in its lifetime, primarily because the bicycle is merely an example of a solid platform to build from (vintage lugged frame circa 1990). Purchased for $15us ...
Read moreColnago restoration
Latest post 4 weeks agoHi everyone. A bit repetitive from my intro in GF, but this is the correct section for this post. I’m new to vintage bikes, but I’ve been eyeing a vintage Colnago to restore for a long time. Finally found one and the timing was right to pull the trigger. I’m still trying to identify the exact year, but from my research it’s 1991-1993 Colnago Super PiU. Mostly original, I think, apart from ...
Read morerear wheel for 26" cruiser
Latest post 1 month agoI need a new rear wheel for a 26" firmstrong one-speed bruiser cruiser. I didn't realize there were so many different kinds. Can anyone tell me the axle size. I know it is 36 hole and it is a coaster brake but I don't know the axle size or gauge of spokes. The side of the tires says (557-59) 26 x 2.125. Can anyone give me some advice?...
Read moreIssue recentering side pull brakes
Latest post 1 month agoI'm having trouble with my side pull brakes. One pad rests on the side, mostly stationary, while the other moves freely as I pull the brake lever. I'm fairly beginner at bike repairs, and having looked at youtube videos on recentering brakes, I loosened the mounting bolt, moved the calipers around so they were centred properly, and retightened the mounting bolt. However, after the mounting bolt h...
Read moreCooster brake won't pedal
Latest post 1 month agoMy 26-in coaster brake will not engage when I pedal it just spins and it won't break I've repacked them with grease multiple times tightened it too much didn't tighten it enough I can't figure it out...
Read moreClass Action Filed in Wake of ‘Inadequate’ Shimano Hollowtech Crankset Recall
Latest post 2 months agohttps://www.youtube.com/watch?v=Ny_i51lMTrg https://www.classaction.org/blog/class-action-filed-in-wake-of-inadequate-shimano-hollowtech-crankset-recall...
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 moreSchwinn Meridian 7-speed Chain/
Latest post 2 months agoSo I have a couple of questions that I hope someone in this group might know about or have experience with. This is for my Schwinn Meridian 7-speed trike. 1. Are the derailleur chain and the drive chain the same type? Obviously they're different lengths; and I assume the derailleur chain is a typical 7-speed chain. But what about the main drive chain? Same thing? Or is it a standard single speed ...
Read moreShimano crank inspection process
Latest post 2 months agohttps://www.youtube.com/watch?v=HZLc3Ml4TXQ If anyone reading this takes their cranks for inspection, please share your experience....
Read more
