How would you fix this?
 

Previous goon did this:


https://cimg8.ibsrv.net/gimg/bikefor...61ec0cf07d.jpg

You could try welding/drilling/tapping. I think the probability of it working is low and the probability of it costing more than a new derailleur is high.

Time for a new derailleur.

I would go for a new one mate!

Dumpster.

The money they're asking for these is so silly that fixing it may not be.

Is it tapped all the way through? If so, I’d try a bolt smaller in diameter than what it came with, a nut for that bolt, and a washer to press against the cable. Tighten down and see if it holds when shifting.

Landfill, or recycling bin, if they will take it. Recyclers will probably just throw it in the landfill anyway though.
Tim

Small metal sleeve or band on the outside - slice off a hunk of a .357 casing...

That looks like it's a result of some defect during the manufacturing process. I can't imagine a mechanic causing that sort of failure in a derailleur actuating arm.

When working on those long ago I did not like the design. As the arm moves the cable’s direction of force changes and the cable is not, only deflecting

I have not measured it, but it came off a 1969 chromed PX10, so that could be metric tubing; it wasn't an original part (neither was all the other gold stuff) and could possibly have been for 28.6 - a goon would think the cable getting loose was a loose cable anchor bolt instead of the derailleur slipping on the frame.

First I'd cut that threaded part off. Then try to make a "sleeve" from 1/16" or so steel stock with a nut welded and attaching it to the arm with 2 3/32" bolts. Not sure it will work, but since the alternative is throwing it off...

Even if a previous owner or mechanic thought the cable to be loose, I'd expect any anchor bolt over-tightening to strip the thread in the aluminum actuating arm, rather than crack the boss around the hole, if the part was sound. While tightening may have ultimately have caused the failure, the root cause would appear to lie with a defective or under-engineered part, resulting in a propagating crack. I haven't see any significant history of this type of failure on these derailleurs, so I'm leaning towards a defective part.

It looks like a later 1970's gold anodized Simplex FD. The aluminum used on these and most other Simplex parts from the era were not great, and I've had one crack at the clamp before.

The example I worked with was also gold, so I'm not sure if the anodizing made the gold variations even more brittle than those in bare aluminum.

-Kurt

i've got a spare SLJ fd from a long ago abandoned project, and would happily swap it for something equally tasty (and just as silly-priced on the 'bay), if that's of interest?


https://cimg6.ibsrv.net/gimg/bikefor...97e2c035ca.jpg

I run up against this sort of thing all the time. When a replacement part is pricey, I just install anything that I have on hand that will work with the rest of the transmission. Sutour anything is a pretty darn good choice. Then I wait for a chance to snap up what I seek at a price that I can afford. In my mind, the search and find for a good price is part of the fun of this hobby.

This old lady is darn near completely original. Sadly, I did not have a decent handlebar so I used what would work, be it brand, model of period correct. And, guess what...

A decent priced handlebar, exactly what I need, showed up on Ebay today. I put up an item on Ebay that might help me be able to make the purchase. If not, no biggie. I do not mind the hunt.

Anodizing is basically a corrosion resistance coating of aluminum oxide. It chemically bonds to the part, growing on top of and into the aluminum part. The anodization is harder and more brittle than the base aluminum. While it is more common with thicker, hard anodization, subsequent machining operations, such as drilling/re-sizing and tapping of the anchor bolt hole, can causing micro-cracks in the anodized layer, which will eventually propagate into the base aluminum. This is a known issue with hard anodized bicycle rims, particularly those without load distributing eyelets..

Yes, usually that's the way when you need to make it work - but this mech has been buggered since I got the bike in the previous century and it's been a long wait for that price.