30. How to Overhaul A Bottom Bracket
How to disassemble, re-grease, reassemble and adjust a cup and cone bottom bracket.
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.
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.
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.
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.
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.
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.
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!
I have a schwinn sidewinder I bought at walmart, and may need to replace the bottom bracket. I believe I will need a crank puller, at the very least, and some sort of specialized tool for the bottom bracket itself (maybe). What do I do to get the correct bottom bracket for my bike?
It's an OK bike and gets me where I want to go.
I am mechanically inclined, and do some of my own auto repair work, but I've never done much for my bike other than replace the innertube.... Read more >>
Hi there ,
Ive been given what I believe to be a peugeot ph8 by my uncle . Ive narrowed the year down to somewhere between 79 and 83 .
The serial number is 0931716 PH8CE 60.
Here are two pictures of what I think is the exact same model except my one has cottered cranks .
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Is there a good way of knowing what size of BB your bike takes, without having it at hand, and not having the specs from the manual.
I would like to get the tools and part at the same time to avoid repeat trips to the bike store, if I can help it.... Read more >>
I am in desperate need of some assistance here.
I bought a Shimano Ultegra compact crankset to be fittet on my Specialized SL4 Pro Tarmac - 2012.
I want to replace the bottom bracket as well - but my question is:
Would a Shimano Ultegra BB6700 fit my Specialized bike - or would I need some sort of adapter or something like that?
I seem to be stuck in the BB jungle and does not seem to get the right answers when I google around.
Looking forward to hear from you experts.
Thanks in advance.... Read more >>
I'm thinking of switching out my old Ultegra crankset with an FSA Energy BB30. Will I run into any problems with compatibility? Other than the FSA, my bike would be Ultegra 6700. Thanks!... Read more >>
Hi All -
I'm new to the BicycleTutor Forum and having a hard time finding a replacement for my Chin Haur BB. I have removed the BB from the bike frame and not able to locate the correct BB. I have been to the Sheldon Brown website and I'm unable to understand that busy website. In the process of removing the BB, I broke some teeth off the crankset so I will need a new BB and Crankset.
RFJ6... Read more >>
Is it possible to damage the threads of the bottom bracket shell while undoing the BB?
I'm pretty sure the bike shop would have done it while putting the bike together, but if I can check it's not possible (very unlikely) to damage it while lossening then I'll feel more comfortable complaining til they fix it.
Oggy... Read more >>
Looking at new frames and they all have either BSA or BB68 spec'd for the bottom brackets. Which of these would accomodate an old Shimano UN73 sealed bb unit with English threads? Can't afford new components and a new frame. Thanks.... Read more >>
My bike started recently having a problem where every few hundred meters my pedal arm gets loose and shaky, and I have to stop and tighten again.
I've completely opened and cleaned the bottom bracket and I've replaced the ball bearings (not the cages). The situation has improved, but the pedal still gets loose.
I'm not sure what to try next in order to fix it:
When I replaced the bottom bracket it seemed not too worn out, and only the point where the ball bearings touch on it had lost the paint, and it had signs of fatigue where the crank ... Read more >>
Hopefully someone can identify the wrenches I need:
thanks in advance.
... Read more >>
I have a Origin 8 Adrenaline frame - Info on the frame: 65mm BB Drop?. I bought SRAM red components. SRAM Red carbon TT crankset 130bcd BB30. I'm completely new to bike building. I want to get all the parts together. not sure exactly what BB I need. BB30 but, not sure of sizing. Thanks for your help!... Read more >>
I'm fairly new to bmx terminology so bare with me.
My old bottom bracket and crank was rusted and the threads were severely stripped so I decided to replace them. The new crank, spindle, and bearings I bought are all 19mm and the old ones are 22mm or something. I took the old bearing cups off the rusted bearings to use with my new ones, but they don't fit, so I'm assuming you have to buy new bearing cups specifically for the size of bearing? (I know this is probably a dumb question) And are all bearing cups the same circumference on the outside?
My other question i... Read more >>
Newbie here, so forgive me if I picked the wrong area for my problem.
Kids 16", single speed, coaster bike. Got for Christmas from Wal-mart b/c he LOVES Superman. http://www.walmart.com/ip/16-Huffy-DC-Superman-Boys-Bike/27831881
Worked fine until today! I didn't believe my son at first since he's a little small for the bike. Pedals no longer turn or turn with great difficulty. I can barely move them by hand forward or backward. At first it would work backwar... Read more >>
I've had a Raleigh Silver Jubilee since it was new in 1977. The chainset needs replacing. I have not been able to find a replacement that gives anything like the correct chain line. Can anyone help?
The alternative would be a shorter spindle. The original was a 126mm 5s. I can't find anything shorter to fit the 70mm frame. It probably needs to be about 116 mm. Help?
If a shorter spindle is not available I could replace the existing bearings with a cartridge but I can't find anything 26tpi for a 70mm shell. What would you suggest?... Read more >>
Looking to rebuild the entire drive train on an old frame. To start, I'm looking at the Shimano Tourney A070 double crank set. But I can't make head or tails of the spec sheet I've found for a compatible BB? Shimano's recommendation is the BB-UN26, for which there are at least 5 different lengths (from what I can tell from some ... Read more >>