Anyone drilled a seized bottom bracket out of an oclv frame?

[paul8valve]

I couldn't shift it.

The best mechanic in 100 miles, who's also a mate, couldn't shift it.

We're both afaid to apply any more force in case the frame gives up before the bonded bb does.

Time for the drill. Campag cartridge bb in a carbon Trek frame.

Anyone here had to take this last resort?

 

[Nob]

Forget the drill & use a vertical mill as you’ll have more control & the frame can be safely clamped toma secure table.

 

[paul8valve]

Forget the drill & use a vertical mill as you’ll have more control & the frame can be safely clamped toma secure table.

Thanks for the tip!

 

[mattr]

Yes.

Not an OCLV though. Drilled the shit out of one face of the bottom bracket until we could get the axle and bearing out. Only aluminium bits left in the shell then. Used a mill (as above) to get most of the rest out, think we used an offset boring tool (? Just a longer finger with a cutting tip and an offset head.) rather than a straight mill as we couldn't get the right size. Just ended up collapsing in on itself and wrapping round the tool.

Then tapped the bearing out of the other end of the bottom bracket. Taking the bearing out meant we could just unscrew the other side with a bit of effort.

 

[Woz]

I'm not too familiar with Campag cartridge bearings, but my course of action would be less brutal,
in part because I don't have a pillar drill:
- Disassemble the cartridge first. A sealed Shimano cartridge type UN72 / UN55 can be pulled
to pieces with just a large leather sewing needle or precision screw driver. You do not need
heavy machinery, but thinking about it you may need a stanley knife to hack away at
the dust seals if obscured by the cups.
- The shell and cups will then be empty. Take hacksaw blade off, thread in the cartridge void, attach
saw and....well....patiently saw away without going too deep to ruin the threads. Two cuts
will help so the cartridge collapses, but that may not be necessary. Make sure you have a
good supply of blades!

 

[integerspin]

No idea what those bearings are like but I have removed plenty of shimano style bb.
I did make a cutter to remove the retaining ledges on the threaded sleeves, but it's not
needed I can cut them out with a die grinder just as fast; I use a slot drill in a die grinder.
Pull the cartridge out with a puller.
Finally saw slots in the threaded sleeves, two or three does the job, then the threaded bit's
come out by hand. I generally get asked to get them out when the cups have been
mullered and no way will a spanner get them out.

 

[paul8valve]

Thank you, everyone for the replies/advice.

I will report back...

 

[shredderxle]

Re:

Sadly this was the end of my otherwise (at the time) perfect Trek 5500 OCLV.

Over time the adhesive bonding the metal threaded shell into the carbon had become detached with a knackered bottom bracket stuck in it. I dont think it would take too much force on an old carbon frame to cause the shell to detach. Milling it out might be an idea but you will need to be very very careful in not damaging the threads on the sleeve as if that becomes dameged i would imagine the frame would be a write off.

 

[zetecmk2]

you can re bond a new insert in the frame, plenty of info on the internet. i will attempt this with a carbon road frame i have.

 

[mattr]

It's pretty straight forwards if the insert isn't damaged and the carbon is still in fairly good shape.