Bottom bracket - how easy?
Alibran
Posts: 370
I've started getting a slight clunk when pressing down on the left crank recently. It only happens at the moment when I'm out of the saddle, and I think I've read somewhere that it's a sign that the BB needs replacing. (The bike has done about 6,000 miles from new, and 4,000 of that was on wet Cornish roads.)
If I get the tools to do it myself, is replacing a BB a fairly straightforward thing?
If I get the tools to do it myself, is replacing a BB a fairly straightforward thing?
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Yes, I recently did this for the first time (well, I didn't replace it, but I bought all the tools & pastes etc and stripped, cleaned & re-fitted it).
Tools aren't cheap though, so as a one off would be cheaper to pay the LBS, but I enjoyed doing it myself.0 -
This months Cycle Plus mag comes with a maintenence DVD. One of the vids is a step by step guide to changing the BB.
It might be worth picking up.
Seems pretty straight forward as long as you have the right tools.Cube Agree GTC Pro
Boardman Comp
Carrera Subway Hybrid0 -
Yes it's straightforward and there are good guides on line (e.g Parker Tools website).
However before you do replace it, check for other causes. A common one is a loose pedal. I had the same problem you describe on a ride recently and discovered that the pedal needed re-tighting on to the crank.0 -
You can watch that part of the DVD on-line right now from this web site:
http://www.bikeradar.com/news/article/video-workshop-how-to-change-a-bottom-bracket-31747Summer - Canyon Ultimate CF SLX 9.0 Team
Winter - Trek Madone 3.5 2012 with UDi2 upgrade.
For getting dirty - Moda Canon0 -
Gizmodo wrote:You can watch that part of the DVD on-line right now from this web site:
http://www.bikeradar.com/news/article/video-workshop-how-to-change-a-bottom-bracket-31747
Dunno whether it's just me, but these videos don't work in Chrome - though they do in IE.0 -
Have just done this myself found it very easy, what type of BB do you have?
I bought the tool below, worked a treat.
http://www.evanscycles.com/products/ice ... ?query=ice toolz0 -
That video isn't great as it doesnt mention where to put the anti-seize (on the BB threads) or where to lubricate / which lubricant to use on the chainset arm that goes through the BB (I use lithium grease)0
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Yes, BB replacement is straightforward.
I guess purists might worry about the precise torque when tightening things.
I just tighten to what seems sensible.0 -
It works for me and I'm using Chrome.ooermissus wrote:Dunno whether it's just me, but these videos don't work in Chrome - though they do in IE.Summer - Canyon Ultimate CF SLX 9.0 Team
Winter - Trek Madone 3.5 2012 with UDi2 upgrade.
For getting dirty - Moda Canon0 -
Gizmodo wrote:
It works for me and I'm using Chrome.ooermissus wrote:Dunno whether it's just me, but these videos don't work in Chrome - though they do in IE.
Yeah sorry - stupid me. Ghostery was blocking it.0 -
Sandyballs wrote:Have just done this myself found it very easy, what type of BB do you have?
Well, my next question after finding out it's easy was going to be: how do I find out what type I have?
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Alibran wrote:Sandyballs wrote:Have just done this myself found it very easy, what type of BB do you have?
Well, my next question after finding out it's easy was going to be: how do I find out what type I have?
Easiest way is to tell us the bike model and year...it could be square taper, Hollowtech 2, FSA..to mention a few.0 -
I started at Sheldon Brown, invaluable mewbie website. Start at what type of BB you have then move onto differing sizes if relevant.
I work in a Workshop so had torque wrenches at no cost but to be honest being sensible with the right tools would have worked exactly the same. ie, DO NOT get a length of tubing on the allen key and start grounching, like I have seen some guys do.0 -
centimani wrote:Easiest way is to tell us the bike model and year...it could be square taper, Hollowtech 2, FSA..to mention a few.
The bike is a Trek 1.2WSD bought new in March 2008. It has a standard triple chainset - 30/42/52 - and bontrager cranks. The BCD is marked on the large chainring, and is 130, if that's any help.
(I've had a look at Sheldon Brown, but most of the BB stuff is going straight over my head!)0 -
Looking at the specs for that bike Alibran, it appears you have a square taper BB. You'll see the specs half way down the sheet..
http://www.pigseye.com/mc/bikes/Trek-2008-1.2.html
The only thing it doesn't appear to tell you is the axle length. You may have to remove the cranks and measure it yourself.
It seems you want a square taper BB, 68mm shell, unknown axle length at this time.
In essense,, its quite do-able but you;'ll need the following..
Crank removal tool. Unless someone can tell you what axle length you need you'll need this first so you can go out and get the correct BB, they come in all sorts of different axle lengths.
Also bear in mind there are two different kinds of crank removal tool.
A BB tool and some sort of wrench to tighten the tool itself. That can be a spanner, mole grips, adjustable or sometimes a 1/2 ratchet, again, it depends on the exact tool. If you buy the BB from your LBS, they'll supply you the correct tool.
Bearing in mind a BB could cost you £25, crank removal tool maybe £8 to £10, a BB tool maybe £8 to 10...it soon starts to rack up (those are rough LBS prices)0 -
I bought a Halfords's toolkit for (IIRC) about £25 which has all the tools you need for square taper BB change (crank extractor, BB tool) and quite a few others as well, e.g. some cone spanners, cassette tool, chain tool, chain whip etc.
The quality isn't fantastic, but for the odd one-off job it's pretty good value.
My replacement (square taper) bottom bracket was only £15 I think, from CRC.0
