Rusty BB cable guide bolt and galvanic corrosion on a cable stop

[open roader]

I'm considering purchasing a vintage carbon frame that appears in all respects to be in excellent condtion aside from a rusted BB cable guide bolt.

The frame is OS so I can't see into the BB.

I've seen surface rust on these all the time but this is a 1996 frame and quite possibly the orginal bolt and cable guide.

I'm thinking not a deal breaker but would like to replace it if i purchased the frame. How difficult / risky is it to operate? I would have thought penetrene soak for 24hr, find a torx or allan key that best fits and say a couple of Hail Marys?



Also has some galvanic corrosion (very common on this model) on the rear brake cable stop under the top tube - something a half handy / half scared witless home bike mechanic to tackle? If I manged to successfully drill out the offending rivets and replace the cable stops myself with stainless rivets I'd have that part of the frame re- clear coated.....

[foo on patrol]

I would think the BB one would come out okay.

Foo

[Duck!]

The BB guide bolt is likely only surface rust, and given it's threaded into the aluminium liner of the BB shell should come out OK (normal steel & aluminium don't react too badly, stainless is worse).

I would be inclined to leave the brake cable stop where it is and just give it a very fine clean-up and repaint. Finding rivets that small is difficult enough, finding a rivetting tool fine enough to get in there is a lot worse!

[LG]

The most annoying thing would be the rattle inside the top tube from when you drill out the rivets attaching the cable stop, unless there's a decent size opening at the seat tube end to remove them?

[uart]

The most annoying thing would be the rattle inside the top tube from when you drill out the rivets attaching the cable stop

Yeah good point LG. I can imagine if someone is really concerned about a frame being pristine, that could drive them crazy more so than a slightly corroded cable stop.

I recently replaced a munted cage mount for a women in my cycling group. Was thinking of exactly this issue given that she's fairly "anal" about her bikes and there were no openings in the down tube ends big enough to remove any pieces after drilling it out.. I placed a little dob of slow set epoxy through the hole (after drilling it out) and onto the tube directly under the hole. I then gently shuffled the trapped remnant of the old mount up and down the tube until it got trapped in the dob of epoxy and left it there to set. Was a perfect result with zero rattles!

[uart]

I would be inclined to leave the brake cable stop where it is and just give it a very fine clean-up and repaint.

Agree with this. Just use a stiff toothbrush and vinegar (or vinegar and cream of tartar) and that corrosion will clean off fairly well. Then masking tape off the surrounding tube and dab on a little black epoxy paint with a fine brush. It will stop that corrosion long term should come up very nice.

[ldrcycles]

The BB screw is trivial, but the cable stop isn't. From first hand experience with an early 2000s Kuota Kredo, you won't know how much corrosion there is underneath it until it snaps off. Luckily in my case that happened in the workstand while I was fitting a new cable and not at 80kmh downhill. I had a local framebuilder remove the corroded rivets and reinstall it and I'd have complete confidence in that repair.

[uart]

Luckily in my case that happened in the workstand while I was fitting a new cable and not at 80kmh downhill.

It's not a cable stop, it's just a cable guide. So it won't prevent the brakes from working if it breaks at 80 kph.