broken dropout . Repair or replace?
 

https://cimg4.ibsrv.net/gimg/bikefor...1053636a76.jpg
good side
https://cimg5.ibsrv.net/gimg/bikefor...c4970ff409.jpg
cracked dropout
I had the Carlton Super course stripped and ready for paint when I found this. The frame had a dent in the right seat stay but I had already rolled it out and straightened the stay. Perhaps this happend at the same time as the other damage.
In any case I'm not sure how to proceed. Could it be welded or another dropout installed? What would the labor cost be to do something like that?

I hate to trash the frame if it can be fixed inexpensively.

I say fix it. I’d think a simple short weld there would be inexpensive, quick and sufficient.

Dan

Yep, tig it and forget it.

Maybe a contrarian viewpoint.

Having snapped a chainstay as well as a dropout just like your crack while racing, my advice would be to have a frame builder plug in and braze a new dropout.

This can be welded or brazed fairly easily by a skilled pro. Either way, the key is properly preparing the break according to the method chosen.

If your local bike shop has someone versed in frame repair go there. Otherwise, I've found that the best place to find someone with the right skills is at a motorcycle shop.

BTW, if you know a skilled welder, not expert with bikes, make sure he knows that the dropout is either brazed or silver-soldered into a thin wall tube.

Can you TIG that close to a brazed joint? I'd take it to a good frame builder and let them do whatever process they feel is best. But I wouldn't want a visible TIG bead when they are done - fill and file it. If the frame isn't worthy of a classy repair, buy a different one. I just bought a lugged '89 KHS frameset for $50, which I would be much prouder to own than a higher end frame with an obvious repair.

Yes, you can TIG that close working fast with a good heat sink. As I mentioned, properly preparing the joint by V-notching the area so the bead is mostly sub-flush on both sides is key.

I am neither a frame builder nor a welder, but given that the original dropout probably had a tang that was inserted into the stay before brazing, I would be concerned that this structural element was broken and that a weld would now be bearing all the force that was originally distributed across that joint. Something to consider and discuss with the frame builder who would do the repair.

This is a Basso that came in with a similar break on the drive side. It was sometime back around September and I posted pictures of the process. A cut to make the weld go all the way through the break in the drop out, and five minutes with a wire welder to do the weld. The DO got warm, but not hot where the brazed joint met the stay. I spent about an hour reshaping to drop out by hand and gave it some protective paint until further progress can be made. I left a little of the weld in the triangle of the DO because it only adds a bit of strength to the welded area.
As a younger man I did the removal and re-brazing of a broken Suntour like yours. The weld was far easier and I expect it to hold up to the wear and tear of daily riding. Smiles, MH
https://cimg1.ibsrv.net/gimg/bikefor...6ee24070b0.jpg
A standard wire weld that has been reshaped and given a protective paint until further work can be done.
https://cimg2.ibsrv.net/gimg/bikefor...2df0f25686.jpg
You can see where the break was just in front of the masking tape. There is a slight amount of the weld left inside the triangle to add just a bit of support to the repair area.

As this is a "common" (as common as a frame failure is) location for cracks. I'll bet there are pro builders who have fixed these dozens of times, I've only replaced a few myself. But I don't weld so that tool is out for me.

Somewhat off topic is my breaking a front dropout back just after I left high school. Cracked across the section between the blade end and the wider slot portion. The blade ends had been done in an aggressive "milled " (as Paterek describes it) style and there was a tad of undercutting to the dropout surface IIRC. Additionally the frame had been chrome plated. Even still with what I now know about this stuff I remain surprised in my front dropout fracture and suspect the joint was cooked "well done" during brazing right from the beginning. Andy

The "proper" repair is to fit a new dropout, probably the other side too. The "probably get away with it" fix is to open up the crack and TIG weld it. Be sure to check dropout alignment after the repair - poor alignment may have caused this failure, it can also cause premature axle failure.

That dropout certainly has a lot of clamping wear on the inside of the drive side. It looks like it was under clamped and jostled around, then over clamped and splayed open some. The drive looks like it will only clamp maybe secure to one spot. If you are going to fix the dropout then I would do some metal to that spot indexed.

the great Brian Baylis used to say that replacement of the DS dropout was the most common repair he performed. He believed that running an oversized axle (where a 126mm axle was just "forced" into a frame with 120mm spacing) was the proximate cause.

The bending moment applied when the skewer was tightened would cause fatigue and ultimately failure of the DO, because of the forces applied at that brazed joint over 1000s of pedal strokes.

so moral of the story - don't just "force it in there". Cold set and re-align the drop out faces.

/markp