Removing stubborn drive side bottom bracket cup, what are the chances of damaging the shell?

[Tim Hall]

Is there enough of the shell protruding to clamp it in a vice and turn the frame around the shell?

Why bother, when the Sheldon Nut and Bolt method works like a charm and you don't need a vice. The torque applied to the BB shell will be the same in both cases anyway, which is what the OP was worrying about.

 

[Crankarm]

Are you turning it in the correct direction?

 

[C R]

It is supposed to be a reverse thread, so I am trying to turn it clockwise, isn't that correct?

 

[mjr]

[QUOTE 5214965, member: 45"]So why do you want to remove it? I've never needed to, and wouldn't unless the race was damaged.[/QUOTE]
Based on the refusal to answer, I suspect he's trying to steal the magic dust to add to his own bike.

 

[C R]

Based on the refusal to answer, I suspect he's trying to steal the magic dust to add to his own bike.

I did reply, just a bit further up:

Thanks all, the frame is steel, so it may take the abuse. I noticed in the last service what looked like some damage to the adjustable cup, so I am thinking that in the near future I may need new cups, and as I need to have a look at the bottom bracket this weekend, I was considering the possibilities.

As the adjustable cup is showing signs of wearing I am thinking that I may need to replace the whole thing in the not too distant future.

The reason I've done it in the past was to get an axle the right length for the chainset I wanted to fit. Yes, I could probably have found one given enough searching, but they're not the commonest things, and I found it easy to identify a cartridge that suited my needs.

That is part of my thinking, if I need to replace the bb, I may as well put something more modern and get a new chainset, the current one is ok, but will not last forever.

 

[C R]

The bolt method worked a treat. It wasn't even particularly difficult, I put the bolt through the hole with a stack of washers either side, then tightened the nut inside the bb shell with a socket on the inside and an adjustable outside. Once tight I thought I would give it a good push with the adjustable to make sure that everything had bound to the cup and wasn't going to slip, and the cup just turned. I think what this highlights is that the shallow flats just don't offer enough purchase.

One thing though. The nut is now so tight on the bolt that I can't undo it! Good job I was replacing the cup anyway.