10. How to Replace a Cartridge Bottom Bracket

Demonstrates how to remove and install a sealed cartridge bottom bracket.

IMPORTANT: Nuts and bolts on your bike should always be tightened to the manufacturer's specifications.
How to Replace a Cartridge Bottom Bracket
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  • 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.

Required Tools

For this job you'll need a splined bottom bracket tool and a 32mm headset wrench, or a large adjustable wrench.


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.


Related Links

Discuss this topic in the Bottom Bracket Forums

10/15 BMX Bottom Bracket Creaking and Clicking

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 normal for a new bike and will the clicking just disapper after some more rides? It's an american bb and a cheap old school BMX.... Read more >>

09/22 How thoroughly to clean BB before re greasing/assembling.

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 is just mentioned out of completeness?

And a secondary question would be what product to use to clean them. i don't currently have access to any solvents so i'd be buying so... Read more >>

08/12 BB90 GXP Adapter

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 amount of torque I can get it to is about 15nm and there is no play at all.... Read more >>

07/10 Bottom bracket... Strange style I haven't seen before?

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 that contains the ball bearings I just use an adjustable wrench to unscrew it. On this bike it isn't nice and hexagonal shaped to allow a wrench to grip properly, it keeps sliding off. It looks like so... Read more >>

04/28 New cartridge BB stiff

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...

02/06 BB stuck

Hi again! Smile

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 out and the plastic ring that holds the ballbearings in pl... Read more >>

11/27 Cup/cone bracket 116mm

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 118mm can you help?

also do I need to take of the cranks to tighten it properly?

many thanks if you can help?...

10/12 Replacing BB

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. ?
[Image: IMG_0062_zpsurhzcne2.jpg]
[Image: IMG_0060_zpsgruakmoe.jpg]...

09/15 No spindle in the bottom bracket?


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 >>

09/07 Shimano BB-UN26 bottom bracket torque specs

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.#

[Image: BB_UN26.jpg]


Does that mean that the side without the metal threads goes to ... Read more >>

09/03 Help to identify and upgrade Huffy BB bottom bracket


My old cheap 2003 Huffy bike has this BB:

[Image: DSCF2067.JPG]

[Image: DSCF2068.JPG]

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.

-...

05/11 Adjustable Cup stuck

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.


05/11 Frozen bottom bracket on Katmando?

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 >>

04/30 Crank bearing bottom bracket

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....

02/23 German FAG bottom bracket

Hello folks.

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 >>

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