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
Road bike brakes upgrades
Lastest post 5 hours agoHello everyone im looking to upgrade my brakes on a project bike that I'm doing, it currently has traditional lock bolt brake calipers can you upgrade to new style and how to do so? Kris....
Read moreHELP! Bought Schwinn bike by mail and came with rear wheel off and derailleur twisted
Lastest post 2 weeks agoI bought a Schwinn Signature Sport Hybrid 21 Speed by mail (first mistake) and it came with the rear wheel off and derailleur off with the chain twisted with 2 loops. The derailleur is inside out and I have tried everything to untwist this thing with no luck. I can't find a "master link" in the chain anywhere. Any ideas or help would be appreciated. Supposed to be a Christmas present. &n...
Read moreMethods to find punctures in an inner tube ?
Lastest post 2 weeks agoHello ) I was wondering if any of you also fill up your bathtub or a large bucket with water in order to look for a leak in a flat inner tube? That's how I do it ... other methods our there? Holiday greetings...
Read moreBrake pads and metallic pieces
Lastest post 1 month agoCiao. Is it normal to have small metallic pieces stuck within brake pads? How do they appear there? Is it from the rims and braking or did I get them from "the street"?...
Read moreBike is Creaking on the left side during the downstroke
Lastest post 1 month agoAs the title states, what feels like my pedal is creaking when Im on the downstroke on my left side. I say my pedal but based on what I have diagnosed so far I’m not sure if that’s it? I can feel the creak happening in my pedal though. I’ve looked into this and done a few preliminary things to see what could possibly be the problem. So far what I have done is: Removed the pedal, regreas...
Read moreDeep paint scratch or frame crack?
Lastest post 1 month agoHi, everyone! I'd like to ask you about your opinion on whether or not this is just a deep scratch (scuff?) on the paint or a crack on the frame of my aluminium road bike (please see photos below). For context, the area shown on the photos would be the seat tube, right about where it is joined by the seat stays. I already did the "coin soundcheck" test to help me diagnose the problem but I'm still...
Read moreGears slipping
Lastest post 2 months agoI recently changed the cassette on my MTB and ever since doing so the gears seem to be slipping when I put the power down how do any of you suggest adjusting it it changes perfectly and peddles fine until I really try to lay it down on the trials thanks in advance Alan 👍...
Read moreGravity Bike Crank
Lastest post 2 months agoHello Everyone, I have a Gravity road bike and I don't know what type of crank remover will work on my bike? There is an Allen type of bolt that I can take off fairly easily, but inside there looks to be a spline type nut. Lately every revolution of the pedals I can hear a clicking sound and it seems to be coming from inside the crank and I wanted to see if there is any lubricant in there? I ap...
Read moreDisk Brake Spacers
Lastest post 2 months agoGood morning! I purchased a new mountain bike a few weeks ago and picked up a frame adapter so I could put it on my trunk rack. The problem is that the front wheel is really low. A hitch mount is in the future but for now I figured I would just remove the wheel. My question is whether I should pick up a disk spacer or could I just use a chunk of cardboard? Not traveling all that far but don't wan...
Read moreHelp.. Rear derailleur wrong position?
Lastest post 2 months agoI've tried searching for YouTube assistance but to no avail. Cycled to the shops this morning and the gears weren't functioning, had a look and something has gone horribly wrong. It's as though the chain is suddenly inches longer than it should be and it isn't holding any tension unless the derailleur sits all the way back (image attached) almost so the chain is touching itself as it travels throu...
Read moreShimano tourney
Lastest post 2 months agoMy Apollo feud rear gear set was trashed when the bike was loaned ,the click on lock on was damaged how can I fix it please so I can be mobile again.thank you...
Read moreRemoving Front Derailleur on a 3x?
Lastest post 2 months agoI'm a newbie but I'm planning to remove the front derailleur off of my 3x8 GT Agressor Pro. Could I get some pros and cons of doing this and what I should next if I remove it? Thanks ...
Read more3speed hub problem
Lastest post 2 months agohi. i sometimes have a weird grinding sound but this only happens in shift 1 and never in 2 or 3 and most of the time it happens when after a traffic light stop. 1/9 of the time orso. but quickly goes back to the normal sound after i stop pedalling and pedal again. my question is: do you think its a planetairy gear problem inside the hub . i need a cone wrench to open the hub to look tomorow. ...
Read moreOld STX-RC 7 speed upgrade compatibility
Lastest post 2 months agoHi Folks, I hope someone on here will be able to give me a steer. I'm trying to upgrade my wifes old Marin Bear Valley SE (1995) but I'm really struggling to work out what Shimano replacement parts I need. The current spec is:- https://www.bikepedia.com/QuickBike/BikeSpecs.aspx?item=32407 Crankset Shimano STX-RC, 22/32/42 teeth - ideally I'll replace the chainrings Cassette Shimano 7-speed, 11 - 2...
Read moreWeird brake hose
Lastest post 2 months agoHi I bought these SRAM force 1 brakes and they seem to be really unusual. Has anybody ever seen a hose like this? I need to shorten it to run it through the frame but I'm baffled by these hose ends. These were sold as "pre-bled", which I didn't notice until I had them. How can I shorten these hose ends? IMG-2735.jpg (Size: 54.74 KB / Downloads: 41) IMG-2736.jpg (Si...
Read more
