Undoing an old square taper BB
Undoing an old square taper BB
Author
Discussion

lingus75

Original Poster:

1,704 posts

245 months

Friday 9th January 2009
quotequote all
I have finally decided to replace the BB on my Orange. It's been wobbly for ages now and I don't trust it anymore, I bought the correct tool and have a long leverage spanner but I cannot for the life of me undo it(I am aware the drive side is opposite thread)! I used another spanner to increase leverage to the point where I thought I would break either myself or the bike. It was last replaced 10 years ago (ish, mainly used for road riding in that time) and I was wondering if it needs heat, or if anyone else has/had similar problems? I really don't want to do any damage but not even sure if LBS will be able to free it.

Any suggestions?

sjg

7,645 posts

288 months

Friday 9th January 2009
quotequote all
Tool in a big sturdy vice attached to an even sturdier bench, and use the frame as leverage. Lots of penetrating oil helps too. Heat can also help free it, just be careful not to use too much if you're bothered about keeping the paint.

ewenm

28,506 posts

268 months

Friday 9th January 2009
quotequote all
Soak in penetrating oil overnight (perhaps pour some down the inside of the seattube if the BB is accessible from there). Put BB tool in place and hit it with a hammer - the impact should help break the corrosion holding the BB shell in place.

Parrot of Doom

23,075 posts

257 months

Friday 9th January 2009
quotequote all
Loctite Freeze & Release spray is pretty good, spray it on, instant shrinkage breaks the crud holding the cup on.

lingus75

Original Poster:

1,704 posts

245 months

Friday 9th January 2009
quotequote all
No bench available so penetrating oil and a hammer will be first attempt. Fingers crossed as I cannot imagine the nightmare it must be to get a BB out of a frame if the shell breaks eek

zippy500

1,883 posts

292 months

Friday 9th January 2009
quotequote all
If its not an ally frame, try some gentle heat. I thought drive side was a normal thread i.e. undo counter clockwise. The free side is left had thread I thought??

rhinochopig

17,932 posts

221 months

Friday 9th January 2009
quotequote all
G-Clamp across both sides of the BB to hold the tool in place and stop it popping out. And lots of penetrating oil.

giles_anniversar

3 posts

206 months

Friday 9th January 2009
quotequote all
sit the bb in diesel for 24 hours by pouring it down the seat tube

get 1 person sat on the rear tyre holding the tool securley in the spline or you can bolt some tools in using a mixture of diferent waqshers

apply even pressure to the breker bar and that should do the trick hasnt failed on me yet and i do them all day long at work

lingus75

Original Poster:

1,704 posts

245 months

Tuesday 13th January 2009
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Thanks for the advice and completed the job yesterday. Soaked the BB in oil for 48 hours and with the help of a trusty assistant, scaffold pipe and a g-clamp it eventually came loose. It was bloody tight though and we were getting woried about twisting the frame (steel) but all is well.

Just to add Zippy, that the drive-side is opposite thread (clockwise to undo) so remember if you ever have to do yours!

threesixty

2,068 posts

226 months

Tuesday 13th January 2009
quotequote all
I'd take it to a shop and get it threaded and faced now. That way your new BB will go in ok and hopefuly come out again abit easier.