Removing bonded cups from carbon frame

[nicklej]

Hey guys. I’m working on a project right now and was looking to get some parts anodised to match so I can build a replica.

So I’ve removed the cable guides from the frame which use two screws each into the frame and then they had been epoxied onto the carbon too.

(1). I can remove the epoxy from the metal cable guides but is there something I can use to clean up the large lumps on the frame?

(2). I would like to get the dropouts and BB shell anodised. This frame was bought secondhand and someone must have tried to do something similar because the 4mm bolts are rounded off but also bonded onto the carbon. So I need to find something to break down that epoxy to aid removal of the dropouts.

The BB shell is more complicated. The shell is bonded into the frame and the BB threads into that. There are two screws per side to give the shell orientation but also bonded! Again, someone looks to have been trying to get this out by chiselling in between the frame and shell.

(3). The threaded sides of the shell have a flange on them some I could use a bearing removal tool to whack the crap out of them but is that safe to do? Probably not on a 30 year old carbon frame.

Any advice on this would be great as I’m super keen to get all these metal parts anodised but if it’s not safe then I’ll have to skip it

Thanks
Jake

 

[Dr Dremel]

Acetone would remove epoxy resin, but as carbon frames are made of epoxy (well and carbon fibre) I would guees it´s nearly impossible to just debond the BB shell without weakening the frame´s structure, as you have no way to limit the acetone to the bonding faces.
Heat will also weaken the bond, but it´s the same as above: You have no way of limiting the heat to just the bonded part.
The brute force approach (hammer) would possibly work if you know for sure that the shells are press fit only (and not epoxied), and even then I´d be hesitant with an old frame.
So my opinion: It´s not worth the risk.

 

[nicklej]

Acetone would remove epoxy resin, but as carbon frames are made of epoxy (well and carbon fibre) I would guees it´s nearly impossible to just debond the BB shell without weakening the frame´s structure, as you have no way to limit the acetone to the bonding faces.
Heat will also weaken the bond, but it´s the same as above: You have no way of limiting the heat to just the bonded part.
The brute force approach (hammer) would possibly work if you know for sure that the shells are press fit only (and not epoxied), and even then I´d be hesitant with an old frame.
So my opinion: It´s not worth the risk.

Thanks for the reply.

I know the drive side cup can spin, not freely, but with force so I assumed that it could be whacked out. All the other entail parts on the frame have epoxy bonding them to the carbon so I suspect it’s the same with the shell.

I guess I won’t risk it! I can still get some other bits anodised that I’ve removed.

 

[tintin40]

Having had the same cups come unstuck from my Trimble. Having to get it fixed was a pain and expensive. So I'd leave well alone. As they say 'if it an't broke'