What Be This Appurtenance?!?!
 

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Sachs road machine fitted with something odd...

https://thecabe.com/forum/attachment...-jpeg.1880963/
​​​​​​https://thecabe.com/forum/attachment...-jpeg.1880971/

failed derailleur spring so someone made a "helper"? :foo:


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Hmmm...my size.


I'd rock it. Might have to replace the dork disk with a new, unbroken one, however.

That looks like a light or generator mount that somebody modified for what you were suggesting, as an auxiliary spring for the derailleur. Note the middle screw that looks like the ones to provide grounding for something electrical.

Campag SR didn't have a top pivot spring, this one does.

that's just ...
amazing.

Hope eRitchie sees this post and starts making an investment-cast custom braze-on to retrofit to any of his early steel frames that use the Super Record RD!

Just what the C&V market has been clamoring for.
:roflmao:

Could the attachment be from a kick stand?

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:D

I'm with Pilot Piscatorial Robert


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Makes me think that the drop out has had damage to the stop and it is designed to keep the derailleur from moving to far forward. Smiles, MH

The presence of an Ideale 90 saddle makes me think the owner has gone full Francophile - the booster spring is an attempt to replicate those early Gallic derailleurs with external springs.