Removal of non-fixed bottom bracket bearing cup

[sukuinage]

Hi,
I've just bought an old mountain bike (early 90's I'd guess). It's in a bit of a state and I'm planning to do it up to use as a pub/ city bike. I'm trying to remove the bottom bracket cups as there were no bearings in it . I've managed to remove the damaged fixed cup and the lockring from the non-fixed cup but I'm really struggling to remove the non-fixed cup. I don't have the Shimano tool (six pin I think) but have had a pipe wrench on it - only effect is to put thread marks in my wrench without moving the cup at all. I've applied WD40 but no movement whatsoever.
Any suggestions?
Before anyone asks - yes I'm trying to turn it in the correct, anti-clockwise, right-hand-threaded direction

[Brucey]

if it is really stuck then you need to get serious with it, e.g.

- heat
- 'massaging' the bottom bracket shell with two hammers (radial blows, using the second hammer as a bolster)
- grinding a big slot into the cup so that you can use a hammer and drift on it
- grinding flats onto the cup so that you can get it into a bench vice or use a wrench on it
- welding a bar to it which can then be slogged with a hammer

The last of these puts a lot of heat into the cup and this tends to loosen the grasp that any corrosion has on it.

FWIW the chances are excellent that the cup is harder than your pipe wrench, so trying to drive it with the pipe wrench is only going to wreck the pipe wrench.

cheers

[robc02]

You might be able to adapt the method recommended by Sheldon for fixed cup removal:

https://sheldonbrown.com/tooltips/bbcups.html

You would need to turn the bolt head from the inside of the cup so as to tighten it against the cup. This would mean a thick pile of washers or a spacer to bring the bolt head out of the BB shell on the fixed side - assuming you can't get a long reach socket inside the shell.

[hamster]

I'd try Plus-Gas rather than WD40. A week of pickling it with a couple of doses daily helps.

First of all I'd pour a whole kettle of boiling water over the bottom bracket shell, it might be just enough to heat shock and break the corrosion sticking it.

[fausto99]

+1 on the BIG nut/bolt/spring washers diy removal tool on the Sheldon Brown link. I don't think any amount of rust could resist that used with a socket set and extension tube!

p.s. Plus Gas A works much better than WD40

[sukuinage]

Thanks for the tips. I'll follow up on them at the weekend when I get some time again.

Brucey, already found that the cup is harder than the wrench

[willp01908]

An extra +1 for Sheldon`s method. It`s got me out of a couple of fixes down the years.

[Brucey]

+1 on the BIG nut/bolt/spring washers diy removal tool on the Sheldon Brown link. I don't think any amount of rust could resist that used with a socket set and extension tube!...

it very much depends on what bolt you use. A typical high tensile (8.8 grade) M14 bolt has a maximum tightening torque of ~160Nm. This is 'quite a lot' but in the grand scheme of things BB cups can be seized with no practical upper limit to the torque required to shift them. I would estimate that I've had to use about 500ftlbs before now; this is enough to shear off pretty much any bolt that will fit through a BB cup.

cheers

[rjb]

As you have already removed the right cup and the left locking try using Sheldon's big bolt to tighten the left cup a fraction. This offers easier access from outside the bottom bracket and once it's moving you may find removing from the inside, by reversing the socket to use from inside the bottom bracket easier. . Soaking with penetrating release oil beforehand also helps.

[robc02]

+1 on the BIG nut/bolt/spring washers diy removal tool on the Sheldon Brown link. I don't think any amount of rust could resist that used with a socket set and extension tube!...

it very much depends on what bolt you use. A typical high tensile (8.8 grade) M14 bolt has a maximum tightening torque of ~160Nm. This is 'quite a lot' but in the grand scheme of things BB cups can be seized with no practical upper limit to the torque required to shift them. I would estimate that I've had to use about 500ftlbs before now; this is enough to shear off pretty much any bolt that will fit through a BB cup.

cheers

... and when all else fails weld a bar to the cup, hold bar in a bench vise and turn the frame - hoping the vice doesn't get pulled off the bench!