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

[C R]

As per title. The drive side cup of my bike's bottom bracket is stubborn, so have been servicing from the adjustable side for fear of damaging the shell.

If I decided to go for it and use Sheldon Brown's bolt through method , what are the chances of doing terminal damage to the shell? Has anyone tried and regretted it afterwards?

 

[mjr]

I've not tried it and usually service them from the adjustable cup side. Why muck with the fixed cup if you don't need to?

 

[davidphilips]

As per title. The drive side cup of my bike's bottom bracket is stubborn, so have been servicing from the adjustable side for fear of damaging the shell.

If I decided to go for it and use Sheldon Brown's bolt through method , what are the chances of doing terminal damage to the shell? Has anyone tried and regretted it afterwards?

I have used the bolt method a few times and its great works really well with l/h threads.

 

[PpPete]

Chance of damage depends of frame material I'd say.

I've tried Sheldon's bolt method on an old steel frame. BB had probably been in there 40+ years.
No luck getting the cup out, despite using massive amounts of torque, enough to shear the stainless steel M15 bolt I was using, but no damage to frame.

I suspect that, had it been an aluminium frame, that amount of unction could have torn the shell right out of the frame.

 

[C R]

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.

 

[biggs682]

Done it a few times never had any issues

 

[Ajax Bay]

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 had this. Solution: Attack the drive side (because the adjustable cup had lost some splines when I had previously tried (and failed) to remove) and replace with a UN55.

 

[C R]

I had this. Solution: Attack the drive side (because the adjustable cup had lost some splines when I had previously tried (and failed) to remove) and replace with a UN55.

If I manage to get the fixed cup out I'll definitely replace with a UN55. How do you hold the frame to apply force on the bolt?

 

[Ajax Bay]

Frame horizontal (Edit: ie on the floor). Minimal chance of damaging a steel frame this way, imo.

 

[PpPete]

Maximum force best applied with wheels on ground, rather than in a stand.
I broke my first stand by applying too much force to a stuck component on the bike held in the stand.

 

[Tim Hall]

If I manage to get the fixed cup out I'll definitely replace with a UN55. How do you hold the frame to apply force on the bolt?

Keep the wheels on the bike and stand it on them. Arrange things so that you're pushing the bike into the ground, rather than lifting it. You may have to extend the tommy bar with a handy length of scaffold tube to get the necessary torque. What do you mean you haven't got a handy length of scaffold tube?

 

[mjr]

You may have to extend the tommy bar with a handy length of scaffold tube to get the necessary torque. What do you mean you haven't got a handy length of scaffold tube?

Hollow-ended extending garden tool handles (the sort you swap the tool heads on) work well if the tool fits, but don't use them on full extension.

 

[tyred]

It will work but don't under-estimate how tight they can. Keep the bike on it's wheels if possible. Use a high tensile steel bolt, 5/8" or 16mm is the perfect size, and good quality tools that fit well. You really don't want it to slip. Some sockets, especially cheaper thick ones may be too thick to fit into the BB shell to hold the nut on the inside. I needed a 4' extension to unscrew my Raleigh Twenty fixed cup and it released with such a crack I thought I had broken the frame.

Doing this shouldn't damage the cup as the washer won't be putting pressure on the bearing track.

 

[C R]

[QUOTE 5214910, member: 45"]What have you been using to try to wind the cup out?[/QUOTE]
I got the special spanner that fits on the shallow flats and gave it a few pushes, but was concerned that I might damage the shell or the wheels, that's why I wanted to know about people's experience with more drastic methods.

 

[Drago]

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