Helicoil front derailleur pinch bolt?
 

How successful is it?

If there is enough material left around the hole, very well. Some types of mechs have helicoils installed at the factory.

Sounds good! Plenty of metal available.

Thanks,
Jim

Mmmmmmm, is it deep enough for the Helicoil insert? It sure is easy to try; nothing lost (other than the $20 or so, it's only money) in picking up one of the standard thread replacement kits. Helicoil is just one name brand.

If you have never done it before, practice on a similar size hole on a junk piece of gear. It is not hard, it is just that the second time doing almost anything goes better than the first.

Helicoil works really well provided you have enough material to accept the insert. I've repaired numerous auto cylinder heads using helicoil. If it'll stand up to the temps and pressures that a cylinder head is subjected to, it'll work just fine on a bike.

Who would sell an insert of the appropriate size for an FD bolt? I can't see an auto parts store carrying it. I have the same problem and am getting tired of waiting for a warranty replacement.

Two alternatives.

1. FD clamp bolts are most commonly M5x0.8 mm. Just retap the hole it to M6x1.0 or 1/4-28 which require less surrounding metal and less work than a Helicoil

2. Buy a longer 5 mm bolt and use a nut at the other end.

Yup. Re tapping to m6 should work fine, and if it doesn't you can still Helicoil it. Usually, a stripped out m5 bolt hole can be tapped to m6 without drilling. Just make sure it's thoroughly stripped out first.