Bottom bracket - replacing

Bottom bracket - replacing

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Discussion

Moose.

Original Poster:

5,342 posts

248 months

Thursday 15th November 2007
quotequote all
Is this something I can do myself or does it require specialist tools? Mine is well over due replacing now so figured I'd better get it done soon. Any recommendations, I'm thinking something Shimano around £20-£30.

Parrot of Doom

23,075 posts

241 months

Thursday 15th November 2007
quotequote all
Yes you need special tools, although they're not expensive. Crank extractor, 1-2 BB removal tools, and a tub of grease.

WildCards

4,061 posts

224 months

Thursday 15th November 2007
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What cranks have you got?

I changed over to a Hollowtech II LX crankset and BB last year and loved it, then when I bought the Commnecal it came with Race Face Deus XC gubbins, which also feels very nice. If your doing BB only you'll be limited to what fits with your cranks.

BOR

4,830 posts

262 months

Thursday 15th November 2007
quotequote all
I tried to replace mine a couple of weeks ago. I got the plastic cap off the LHS, no trouble, but the RHS defeated me. I tried WD40, some sort of freezing, penetrating oil, even petrol !!!!! (recomended by LBS). Nothing.

The LBS got it out for a few quid, which is what I'd recomend.

gbbird

5,193 posts

251 months

Thursday 15th November 2007
quotequote all
should be easy to do with the right tools. saying that, I have only fitted them and never had to remove.

Moose.

Original Poster:

5,342 posts

248 months

Thursday 15th November 2007
quotequote all
From the spec sheet:

BOTTOM BRACKET
Power Spline Cartridge Sealed

CRANKSET
Truvativ ISO FLO, 42/32/22 with Power Spline interface

Anyone care to recommend some links to which tools I'll need?

I am slightly concerned with the removal process as one of my friends had serious problems getting his old one out. I guess it's a case of give it a go and if all else fails nip down to the LBS and get them to do it. I feel I should at least learn how to do everything on my bike smile

Edited by Moose. on Thursday 15th November 13:38

Pablo16v

2,221 posts

204 months

Thursday 15th November 2007
quotequote all
This is your BB http://www.chainreactioncycles.com/Models.aspx?Mod...
You will need a crank extractor http://www.chainreactioncycles.com/Models.aspx?Mod... and a bottom bracket removal tool http://www.chainreactioncycles.com/Models.aspx?Mod...
You will also need a large allen key (8mm) to undo the crank bolts holding each of the crank arms onto the bottom bracket.

There is a good link on the park tool website on how to remove the ISIS BB http://www.parktool.com/repair/readhowto.asp?id=12...

Moose.

Original Poster:

5,342 posts

248 months

Thursday 15th November 2007
quotequote all
Many thanks for that smile

Moving on from the BB, I feel I may as well replace the chainset too and was thinking this should do the trick:

http://www.chainreactioncycles.com/Models.aspx?mod...

is it really worth paying another £25 for XT to save 74 grammes? Although the XT does look more cool Hmmm, decisions decisions biggrin

pdV6

16,442 posts

268 months

Friday 16th November 2007
quotequote all
Moose. said:
Many thanks for that smile

Moving on from the BB, I feel I may as well replace the chainset too and was thinking this should do the trick:

http://www.chainreactioncycles.com/Models.aspx?mod...

is it really worth paying another £25 for XT to save 74 grammes? Although the XT does look more cool Hmmm, decisions decisions biggrin
The LX htII is a really good piece of kit. Note that Hollowtech II cranks come with an integrated, external bottom bracket and will require a different set of tools to fit than the ones you'll need to remove the old ISIS one.

As to whether you should move up to XT, it's probably not necessary unless your bike's on a serious weight reduction programme but they do look a bit nicer! FWIW I run LX cranks on both my bikes and it seems bomb-proof.

Moose.

Original Poster:

5,342 posts

248 months

Friday 16th November 2007
quotequote all
I've been doing a bit of reading on the Park Tools website, so I know I'll need the Shimano wrench to fit the new crank:

http://www.chainreactioncycles.com/Models.aspx?Mod...

but I'm not sure if I need this:

http://www.chainreactioncycles.com/Models.aspx?Mod...

as I can't see any reference to it on the Park Tools website and was able to remove the cranks last night using an 8mm allen key confused

Sorry for all the questions, but it's the only way to learn biggrin

Parrot of Doom

23,075 posts

241 months

Friday 16th November 2007
quotequote all
The crank removal tool is designed to push the BB away from the crank. If you can separate the two without one (its easy enough to check if you can or not) then you won't be needing one.

mk1fan

10,648 posts

232 months

Sunday 18th November 2007
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The cranks may have had self extracting bolts which push the cranks off as you undo them, or they maynot have been on tight enough in the first place. Either way their off now so don't worry about it.

On the subject of cranks and chainsets - Wiggle and Chain Reaction were offering the Race Face Evolve XC at a very good discount. It comes with a BB to. The cranks are also compatible with Shimano HTII bottom brackets. I run one of these on my Stiffee and it's great. The rings are a lot more durable than Shimano ones. It also looks a lot better (imoho).

If you fit an external bb then you'll need to get the frame faced up if it isn't already. Your LBS can do this for about £10.

Moose.

Original Poster:

5,342 posts

248 months

Monday 19th November 2007
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mk1fan said:
If you fit an external bb then you'll need to get the frame faced up if it isn't already. Your LBS can do this for about £10.
Was speaking to a mate about this over the weekend as he has HTII cranks and he too recommend I get the frame faced. So, I phoned 3 local bike shops for a quote to remove the old BB (I didn't bother buying the removal tools in the end, as I'd only use them the once) and face the frame:

- bike shop number 1 - £8 to remove BB and £8 to face frame + clean up threads smile
- bike shop number 2 - didn't quote, as reckoned you don't need to face the frame
- bike shop number 3 - £20 to remove BB and reckoned you don't need to face the frame but could do for extra £10

So I think I'll go with bike shop number 1 (although it would be the one furthest away!) unless people reckon it's not worth facing the frame?

mk1fan

10,648 posts

232 months

Monday 19th November 2007
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The reason for facing up a frame is to ensure that the two ends of the BB shell are square and flat. This is to allow the external bearing to be parallel to each other. Manufacturing standards are improving and top end frames don't tend to need facing but the mass produced frames do.

Essentially, if you don't have it done and the (external bearing type) BB fails then you don't have any warranty protection. Unless the shop who said you don't need to do it supplies and fits the BB at which point it's their liability.

£20 to remove a BB! I think I'll quit my job and become a bike mechanic!

Pablo16v

2,221 posts

204 months

Monday 19th November 2007
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mk1fan said:
£20 to remove a BB! I think I'll quit my job and become a bike mechanic!
Yeah thats nuts. 30 quid in total if he wants the frame faced as well. I'm in the wrong job.