What BB do I need?

[Sods_Laur]

I can't get the BB out of my frame - it's pretty old and I am not the hulk. I am attempting to break down an old frame so I can move the components onto another one.

The crankset is a bontrager sport triple from 2008 and some google research seems to suggest I need a BC-73 bottom bracket. Are there others that would work just as well? I have been looking into this for days and I am no closer to a definitive answer.

To be honest this whole bottom bracket thing is massively confusing. any help appreciated.

 

[Tim Hall]

Don't forget that the left hand cup is likely to be/will be right hand (normal) while the right hand cup will be left hand (wrong) thread. (Unless you have an Italian BB, which is unlikely). In either case, the removal tool needs to be turned towards the front of the bike.

The BC73 is a square taper cartridge BB. You'll need to know the shell width (68mm or 73mm) and axle length. Shimano UN55 will do just as well, if not better. Which bike is it?

 

[maltloaf]

A good tip that I read on one of these forums is to remove an English threaded bottom bracket, turn the tool the same way as the bike wheels turn on each side.

A variation on what you already said but this always helps me to remember.

 

[smokeysmoo]

Clamp the edges of the BB cup in a vice and use the frame as leverage to undo it.

 

[Sods_Laur]

My husband couldn't do it either and unfortunately I don't have a vice or know anyone that would. I was definitely turning it the right way - I made that error once before trying to remove pedals and I've been ultra careful since

I'm trying to take it off a Trek 1000 frame which got damaged in a crash so I can put the components on a new one. I'll measure the shell and axle length, thanks.

 

[PpPete]

Spouses are no good at this sort of thing, however muscular. What you need is a small child ....
....
....
- and an 8ft scaffold pole on the end of the tool.
It never fails, plus it amuses child, and teaches them some practical physics aong the way.