Under Bottom Bracket Shell Cable Guide Issue
 

I’m nearing the end of my first restoration project and need to attach the plastic gear cable guide. however I have a problem.

I don’t have the screw or bolt that attaches the plastic cable guide to the bottom of the BB shell as it mustve gotten lost when I sent the bike to get re-painted. I dont know what I need to attach the cable guide as when I inspected the shell I saw two holes and neither appeared to have threading. I’ll attach photos of what the guide looked like before it was sent off to be re-painted. Do I need a screw/bolt or a rivet? Can these be replaced?

Thanks for any help!

Attachment 602322

Attachment 602323

You really just need a short machine screw of the correct diameter. You could either take the frame to the hardware store or find something of about the same diameter as the hole to take with you as a guide. I'd try and get stainless steel

Construction adhesive or epoxy as well will do.

Pop rivets are your friend.
Jon

That was a rivet, but a self taping machine screw should also work. The cable guide is nylon, which epoxy generally won't stick to.

Some bottom bracket sets include a plastic sleeve to keep crud out of the bearing. Any screw, rivet, stud, etc. used to hold that guide should be short enough to not interfere with insertion or removal of the sleeve.

Most of these suggestions are overkill!

Once the cables are run and properly adjusted, all that guide needs to do is not slip. The cables will keep it snug to the frame (unless you run them slack and then cross-chain small-small, in which case shame on you twice.) The fastener has only to resist a tiny amount of shear forces. A pop rivet or a small machine screw is all that is needed. You could even use a plastic auto trim anchor that fits the hole.

Is self tapping machine screw an oxymoron?

Nope.

https://image.slidesharecdn.com/scre...?cb=1378353349

Guess not.

The ones I buy come with M5 button heads, but you can tap and drill whatever works. An M5 or 10-32 drill and tap set would do the trick. Make sure you use a "just right" length screw. Too short, obviously you won't catch enough threads, too long and you could hit a sealed bottom bracket.