Bicycle frame repair

By diddidit Date 03-15-2005 02:20

Hi, new member here. I have just enough welding knowledge to be dangerous!

In any case, does anyone have any experience with repairing bicycle frames? My nice Italian steel frame has developed a crack in one of the dropouts. Here's a pic:

http://homepage.mac.com/diddidit/DIDstuff/Crack.jpg

The frame is a chromoly steel, probably along the lines of 4130. The dropout, where the crack is, is probably investment cast, although it's possible that it's forged. I don't ride the bike a lot anymore, but I would like to have it available; the crack is in quite a highly loaded area.

It may be possible for a frame builder to replace the dropout (it's brazed to the frame tubing), but that would almost certainly involve a lot more money than I really want to spend for something that's no longer a primary ride. I'd guess that someone could GTAW the thing back to life; our local community college welding instructor apparently has quite a good reputation.

Any advice would be appreciated! Thanks -

did

By billvanderhoof (****)

Date 03-15-2005 08:16

If you can weld it without getting into the braze filler that would be fine. Otherwise a good neat repair may be difficult. There isn't enough surface area in the break to build up enough strength for a reliable brazed repair. If you don't mind the look of reenforcing plates you might braze them on both sides and get a repair that is strong enough (if ugly).
Bill