10. How to Replace a Cartridge Bottom Bracket
Demonstrates how to remove and install a sealed cartridge bottom bracket.
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.
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.
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.
Hi Just wanted to know how often a bottom bracket needs to be replaced. Would it be like once a year or does it really depend on how often and how much you ride your bike? And finally how would you know if it needs replacing? Would you feel an obvious problem whilst riding the bike? Thanks... Read more >>
Hi, I'm building my first bike from scratch, a road bike for my wife. I have a Ridley Asteria frame (68mm BB shell) and an FSA K-Force Light crankset. I cleaned out the BB housing, greased it up and threaded the BB cups without issue. My problem is with the crank axle. If I just have the drive side BB cup in, the axle pushes all the way through like it should. If I put the non drive side cup in, the axle stops about 5-8mm short of pushing through. If I take it out and try to put it through from the wrong side it fits through the non drive side cup no problems but still stops short of pushing t... Read more >>
Hi, My wife had completely worn out her 2011 Rockhopper SL Comp drivetrain. I've ordered a new cassette and chain but have decided to replace the entire crankset rather than order 3 new chainrings. The current BB is a Shimano BB-ES25 octalink 68x118. I've messed with everything many times but ever a BB so I'm trying to learn about compatibility. Here is the bike: http://www.specialized.com/au/en-au/bikes/archive/2011/rockhopper/rhintrockhoppercomp#specs From what I gather, I can fit any GXP or Shimano 3x9 crankset as a replacement into this frame? Eg. http://www.chainreactioncycles.com/Mobi... Read more >>
Hello, I have a 2009 Trek 7.3fx. I recently bought a new BB, chainset and front mech for it. All of the parts (Shimano Alivio and UN-26 BB) are supposed to be compatible, but now that I have installed them all, the front mech doesn't work. No matter how hard I pull it without the cable on, it only ever comes level with the biggest chain ring, and won't encompass it - so I can't change into top. Is it possible that even though I got exactly the same size BB (68x122), that the new FM needs a shorter BB? Many thanks!!... Read more >>
Hello All My bottom bracket is falling apart and I'd like to replace it with a brand new one. From reading sheldon brown's wesite, i understand that some older raleighs have peculiar BB specs. How do i find out if this is the case with ym 1968 record, and what are the implications for finding a new BB? thanks!... Read more >>
I'm replacing the Bottom Bracket on a 1991 Bridgestone MB-3 and it looks like the bottom bracket pre-dates most of the tools I have. Here are a a couple of pictures that I took. On the drive train side, it's hard to see in the picture, but there are 2 flat surfaces on the BB that look like a large crescent wrench would fit. I quickly measured it to be about 38mms. [attachment=3960] I took the non-dt side lockring off and then came across these holes that I guess you could fit a spanner into? Seems like it's going to need a lot of force to get this off, but maybe a spanner would work... Read more >>
Alright, so I have a FSA K-force crank with a MegaEXO BB 68mm width, and it clicks certain times while riding, and I feel the click up through my feet and so forth. Sometimes the click is so loud other riders can here it and ask what it is. I have done a lot of trouble shooting to see if it might be something else, pedals, drivetrain, etc. It is not those, it is the bottom bracket crank combo. If I clean and lube the crank and BB interface areas, as specified, the click goes away for a short while; 20-30 miles, then starts up again. I have even ran the bike with a Dura Ace 7900 BB that I have ... Read more >>
I know this question has been asked a million times, so I will add another to the count The bottom bracket as seen in the attached pic is of a CCM (Canadian brand) entry level bike from the 80's. The diameter of the shell is 2 inches, roughly 50 mm. There are no threads. From what I've read, it appears that I need an adapter kit to fit another type of bottom bracket? What are my options? Are there any advantages? Thanks in advance.... Read more >>
I have chosen a frame for my single speed build but will this bottom bracket fit it? Frame- http://www.nashbar.com/webapp/wcs/stores/servlet/mProduct4_10052_10053_516649_-1_catNav Bottom bracket- http://www.nashbar.com/webapp/wcs/stores/servlet/mProduct4_10052_10053_536893_-1_catNav Also will whis crankset for that bottom bracket? Crankset- http://www.nashbar.com/webapp/wcs/stores/servlet/mProduct4_10052_10053_501424_-1_catNav... Read more >>
Hi, I just bought a new Vintage 1980s bike frame. How do I know which Bottom Bracket to use for the new frame? Sorry, I'm new so I may ask some stupid questions.... Read more >>
I think the time is coming where I am going to have to change the bottom bracket. I have a Roadmaster Mt. Fury 26" men's mountain bike r4416wmgt. Can someone suggest the proper replacement bracket and tools needed for the change? Thanks, Josephine... Read more >>
Hi all. I'm new to repairing bicycles and hoped some one might be able to assist me with an issue I'm having. I recently bought a 1984 Centurion LeMans RS that needed some minor repairs. Lately it has started making a clanking noise, something like the sound of striking metal when it's under tension, at certain times while pedaling. The noise only occurs when I am actively pushing on the pedals. When I start pedaling from a full stop, the sound is louder. Sometimes the sound occurs when I am not pedaling hard, but it is not nearly as loud and happens rhythmically which each full turn of the ... Read more >>
I'd like some advice on what tools I'll need for this bottom bracket (see attached photos). Ultimately I'd like to re-grease or replace it. Thanks so much for you're help!... Read more >>
ok. basically I jacked up one of my crank arms.(non drive) it was truvativ touro set that I have been riding with for about 5 years or so. Id like to keep my bike looking how Im used to it. I know im weird. its a motobecane phantom cx. nothing much but I love it. anyway. I cant find a square taper crankset or even the correct size bottom bracket 110.5 (mines a rpm 7420) but what I can find is a power spline set. and a powerspline 113or118. I dont even know if the taper or spline makes a difference or how much of a difference the bottom bracket size from 110.5 to 113. would the power spline ... Read more >>
I need to replace my 110.5 mm bottom bracket. There is more choice and a lower price for 110mm bottom brackets. Can I use the 0.5mm shorter one. Is the difference a simple 0.5mm or is there a reason for the very slight different size?. Thanks... Read more >>