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!
Her I have a shimano BB - UN52 68 BC 1.37 x 24
The frame is threaded. I was just wondering if I have too stick with square taperd or can I upgrade ? Also what are they key numbers in that description for size etc. ?
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It seems like there's no spindle in bottom bracket, because when I try to take off the crankset with removal tool, then there is nothing against the bolt to push and you can see hole through the bottom bracket. Do you understand me? How should I take off crankset if there's nothing I can push against?... Read more >>
Ello. I was just wondering if anybody knows what the torque settings for the cups and crank arms are on this? A piece of paper within the packaging states to consult the manual, but there isn't one, not even online (that I can find).
Also, which way does the cartridge fit onto the bike? As you can see in the image below it says.#
Does that mean that the side without the metal threads goes to ... Read more >>
My old cheap 2003 Huffy bike has this BB:
Since I actually enjoy riding this cheap "beater", I plan to do some upgrades. I want to remove this BB and convert to a square taper BB (because I am now familiar with SqT BB's, having replaced two of them on other bikes), and I will install a new crankset compatible with the new SqT BB.
-... Read more >>
Hi, I have a normal mountain bike bought from a department store about a year ago, I've been hearing a lot of creaking noise recently and found out that the spindle is wobbling a great deal ( not just the crank arms ).
After watching some videos, I discovered that the remedy seems to be simply adjusting the hex cup on the non-drive side, since I recognize it to be a ball & bearing bottom bracket.
I don't even need to take off the crank arm, my wrench fits in the gap between as you can see from the picture.
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Has anyone tries the bolt and locknut method for removing the left side bottom bracket bearing race cup. hope I got that right? i was able to remove the right side. the bracket is the spline wrench type like a free wheel but the tool fits in only 1/8 of a inch.
...... method is to get a 2" bolt, 5/8th diameter, and about 14 lock washers, a large flat washer and a nut to fit the bolt. then you put the bolt with all the lock washer slid onto it and insert it through the right side of the bottom bracket and out the middle of the left frozen bearing race cup I want to remove. them y... Read more >>
2006 Gary Fisher Piranha BS:6102 crank is a fc-m410
Hi i am new here and need a lil help with my bike i just brought to ride to work on, so when i ride i can feel that the crank bearings need replacing or bottom bracket i am not a bike mechanic, and i am struggling to find what bottom bracket i need to fix this issue, any help will be much appreciated thanks for your time and reading,
Adam.... Read more >>
This is about a bitchy seized and insisting bottom bracket. It is from a 85 german hercules bike and the BB is the standard german F.A.G by that times. http://de.wikipedia.org/wiki/Innenlager#mediaviewer/File:Fag-g.jpg well in my case both plastic sides are broken after trying to remove it. I have the appropriate tool but the BB was seized so it's jammed and broken in there. After reading some forums I got a soldering tool to melt the plastic. It works. The bearings are e... Read more >>
Hi. I am trying to renovate a Viscount Aerospace and am having difficulty with the bottom bracket. The shell is normal 68mm, but has pressed in 35MM bearings (not BB30) and a 119 mm spindle that (obviously) passes through these bearings.
Bearings are easy to find, less so the spindle! The spindle has been damaged (not by me) and is useless. I have tried all the places I know to find a spindle, but cannot locate. So am toying with the idea of fitting a sealed bottom bracket (the damaged thread, repair type, as the shell is not threaded and too thin to try and thread). Has any... Read more >>
hey I have a 1973 Schwinn Continental frame and fork. I ordered it off of eBay and it did not come with a bottom bracket or anything. How would I go about deciding which bottom bracket to buy?
thanks... Read more >>
First time changing one of these things seemed to be going well.
Cranks came off fine, lockring removed and now im stumped.
I dont see anywhere where I could use to multi-tooth removal tool to get a grip onto the old bracket im not quite sure how to go at it.
Il post a couple of pics up from each side, any help would be much appreciated ... Read more >>
Trying to remove an ISIS bottom bracket from a '06 Trek 1200. Bought the 8-notched cup removal tool (similar to http://harriscyclery.net/merchant/370/images/large/bbt18.jpg), removed the non-drive side no problems, loosened the drive side cup fine. But no matter how much I try to unscrew it, it won't come off! It seems to be on the last thread, but not catching on to 'exit' the screw hole..
Anyone have any idea what's going on here? Also sorry if i'm misusing terminol... Read more >>
I am trying to replace the bottom bracket on an unknown model Pugeot circa 1970 because I broke the crankset during removal (rusted through) and the cups/bearings are quite worn from age and rust.
Unfortunately, I don't know much about the bike or the proper terminology but the bottom bracket is 68mm wide, the cups screw on clockwise and the threads look about 1mm apart but I cant tell more than that. The cottered spindle is 145mm end to end, ~55-56mm between the bearing retainers (on the spindle) and the drive side is ~3mm longer than the other.
I was h... Read more >>
I am trying to restore an old 1955 Triumph that I bought at a car boot sale. I was removing the bottom bracket today and have been having a problem removing the lock ring. I was using a hammer and punch to turn the lock ring (it was very stiff). Once it was loose I managed to remove it almost completely before it got stuck again. When I resumed using the hammer and punch I ended up just loosening the bracket cup which has now come free with the lock ring still attached.. I can get the cup back on but the lock ring doesn't go flush and I am concerned it will not be properly se... Read more >>
Hi, I just bought my first fixed gear bike last week but yesterday the bottom bracket loosened. I went to the closest bike shop and asked if they have a tool/wrench for tightening it. I showed the photo of my bottom bracket and i was told that this type of bottom bracket is not suitable for fixed gears. Do I really need to replace it? I'm still a noob regarding bike parts and I'm having second thoughts about replacing it.
Here's a photo of the part of my bb that got loosened:
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