How to Replace a Cartridge Bottom Bracket
Demonstrates how to remove and install a sealed cartridge bottom bracket.
- 01:30 - The torque specification are actually 25-30 ft-lbs, or 300-360 in-lbs. Check with the manufacturer for exact products specs.
This tutorial will demonstrate how to remove and install a sealed cartridge bottom bracket, found on most modern bicycles. You’ll need to remove both cranks first, so be sure to refer to last week’s crank removal and installation tutorial before you begin.
A cartridge bottom bracket usually has two main components. The cartridge contains the sealed bearings and spindle, and is usually threaded into the right (or drive side) of your frame. The lockring supports the opposite end of the cartridge and is usually threaded into the left (or non-drive side) of your frame.
Bottom Bracket Removal
Remove the drive side first, using the lockring tool and wrench. On most bikes, the drive side has a left-hand thread, so you’ll need to turn your wrench clockwise to loosen. Once the drive side is removed, the non-drive side should easily loosen and unthread by turning counter-clockwise.
Before installing the new bottom bracket, carefully clean the threads on the inside of your frame, and then apply a thin layer of waterproof grease to the threads on both sides of the frame.
You’ll notice that most bottom brackets have an ‘L’ and ‘R’ written on them to assist in installation.
Bottom Bracket Installation
To install, first thread the new lockring part way into the left side of the frame by turning it clockwise. Don’t tighten the left-side yet.
Thread the cartridge all the way into the right side of the frame by turning it counter-clockwise. Tighten it with about 25-30 foot-pounds of pressure (300-360 inch-pounds) using a torque wrench. Torque specifications vary, so it’s a good idea to check the manufacturer’s website for their exact product specifications.
Now you can finish tightening the left side clockwise until it is nice and snug.
- Park Tool: Cartridge Bottom Bracket Service
- Sheldon Brown: Bottom Bracket
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- Park Tool PAW-12 Adjustable Wrench
- Park Tool Wrench Combo Set
- Park Tool SK-3 Starter Mechanic Tool Kit
- Park Tool PK-3 Professional Tool Kit
Discuss this topic in the Bottom Bracket Forums
I have a 1999 Trek 820 AL whose bottom bracket is dying. According to the spec sheet, it's a Shimano BB-CT92E, 68mm shell, 116mm spindle, English threading. What is the easiest way to identify a suitable replacement? I found a NOS BB-CT91 with the same measurements on eBay for $20, any reason not to pull the trigger on that? Thanks!...Read more
Good afternoon internet hive mind. A friend has inherited a bike that has a wobbly bit somewhere inside the bottom bracket. I'm taking bits from old bikes to cannibalise into a new one to make it rideable and to be honest the whole thing is a great learning experience for me anyway, but I've hit a problem. In the past I've removed the bottom bracket with the correct tools, then to remove the bit t...Read more
I'm new to bike repair and maintenance, and I'm using my Dahon Speed 7 as my guinea pig. So far I've managed to replace the rear wheel, remove the casette, replace the brake cable and adjust the derailleur. My next project is to remove and replace the bottom bracket. I understand I need some tools to do this, but I'm not sure which ones. So, can anyone tell me which of the following I need? ...Read more
When I ride in a fairly low gear, about the 4th or 5th easiest gear and am peddling pretty hard, I hear a knocking sound that sounds like the bottom bracket, difficult to tell though. When I ride harder in even lower gears, it doesn't knock. Very confusing. I've just had a major maintenance completed at a good shop but it still happens. Any ideas out there about what it could be? Thanks! Dan...Read more
Hi, I received my brand new BMX last week, and already on the next day after I assembled everything I noticed an annoying creaking noise and felt some kind of clicking of the cranks under load, for example if I ride uphill. I disassembled the whole bottom bracket, cleaned everything (althout everything was clean and greased already) and regreased it. Nothing changed. What should I do? Is this norm...Read more
I've read a bunch of tutorials (including the sticky here) and the only part i'm unsure of is how thoroughly one must clean out all the old grease before regreasing and reassembling. I've wiped everything down and it is reasonably clean. Wondering if that bit of grease stuck in the bearing ring will contaminate and ruin the new grease or if a bit of mixing doesn't matter and the cleaning step...Read more
Has anybody else ever worked with this? I have installed the bearings which went into the frame by hand and are straight, but whenever I get to tightening the cranks it seems to bind up and there is no way that I will be able to get to the recommended torque level of 48nm. The cranks have the correct order of wavy washer then seal on the drive side and just the seal on the non drive side. The amou...Read more
Just replaced my bb sealed unit. Taken it for a test ride and it seems really stiff any suggestions to cause. Doing a long charity bike ride Sunday and need to sort it before then Any advice great fully received...Read more
Hi again! I had some problems on my MTB suntour BB recently, first it made some noise, than it started wobbling, so I decided to replace it. It is a 68/122.5 sealed square tapered BB, so I bought the same thing just a Shimano. I tried to remove the non drive side, no luck it is stuck, I tried to remove the drive side and it came off very easily, the sealed BB was open, the ballbearings rolled o...Read more
Hello all, I hope you can help me out here, I have a Jamis Beatnik single speed bike 2015 the cranks have a lot of play in them. I have tried tightening the lockring on the NDS as it was quite loose. but it makes no difference at all. Do I need a new BB I was thinking of a shimano sealed cartridge type but the actual spindle size of my bb 116mm and shimano don't do that size only 115mm or 118m...Read more
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. ? Thanks ...Read more
Hi, 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.# L R Does that mean that the side without the metal threads goe...Read more
Hi, 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. -Can you help to identify this old Huffy BB? (Is this...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 brac...Read more