I have an old Campagnolo Record rear derailleur, the steel version from the 1960's. It's a pretty cool old piece, but heavy! It seems to be all steel, even the jockey wheels. It has some rust I'd like to get rid of-- can I just toss the whole thing into a bowl of oxalic acid?

The derailer body is chromed bronze.

I just did a Gran Sport, came out perfect, no ill effects to the finish or anything else.

Try to take it apart as much as possible to let the acid get in and do it's work. Nice part, have a bike to go with it??

Go for it.

Then you HAVE to build a bike for it, for our vicarious enjoyment.

I’ve soaked lots of parts in a weak solution of OA and H2O without seeing any ill effects to date. After the acid has done its job, all you’ll have to do is build a bike around it.

i wanted to include this in my earlier post but i was working from my phone


i completely disassembled the derailleur, every last bit, then soaked the steel bits (basically everything) and main body.

from this:




to this:





there was a bit of pitting to the chrome, that's the brown speckling stuff you see, not rust.

Thanks for the tips, I've never worked with OA before.

No, I don't have a bike to go with this. I found it in my LBS, they had some boxes of old parts and let me sift through them. I haven't actually tried it to see if it works, although everything seems to move the way it should. Feels very solid. It's missing the mounting bolt but otherwise seems complete. I might be able to get a Gran Sport rd which is supposedly in bad condition but could be a good parts source. Are the mounting bolts interchangeable? Any other parts? They look very similar.

I have most of a Record/NR group and some Universal 61 calipers, old Cinelli bars & stem, etc. I was thinking of doing a 70's build with them, but with this derailleur I could do a passable early or mid-60's build without too much problem. That leaves the frame, of course (by the way, I ride a 58-59cm if anyone has a lead on an older Frejus, Olmo, etc.). So far my oldest bikes are late 60's models (67 Atala Record and 68 Lejeune Tour de France), which are quite practical because it's relatively easy to find parts for them. Going back just a few years earlier the parts supply seems to shrink dramatically, and I haven't wanted to deal with the hassle of locating semi-rare and rare parts. But maybe this is a good opportunity to try something a little different.

Better to take it apart if you can, but no problems cleaning in a water (and acid) solution as long as you can dry it before the water dries inside. You might go from the first bath to a hot water only rinse and then finally an alcohol dunk to chase off the water. Otherwise a hot rinse then blow out as much air as possible and immediately oil the hidden recesses.

By the way, I've done plenty of vintage watch cleaning in the past and water based cleaners are fine as long as you dry the parts throughly.

Brass wire brush or brass Dremel brush is good for those fine rust pits.

David S.

Definitely go for a 60s build. Doesn't have to be 100% period correct to get started. The RD, Universal 61s, and Cinelli bar/stem are most of the most visible parts, so you're well on your way.

Nice find!

Just think dilute, really dilute, like 0.4% by weight or so. Then use baking soda to neutralize (won't take much of that either).

As far as reusing it, I save my OA solution and reuse it many times. Typical frame bath does at least five frames plus a myriad of parts before its done. Typical parts solution gets used again and again.

Does your derailleur have any aluminum on it? I don't really know or (maybe I shouldn't admit this) much care about old Campy stuff. But keep in mind that OA will eat up aluminum. When I have to de-rust a derailleur or other assembly than contains both steel and aluminum parts, I dip it overnight in a water-based product called Evapo-Rust, which dissolves rust extremely well but does no harm to aluminum. It's kind of spendy at about $8 a quart, I think, but you can use it over and over. I've been using the same quart for about a year now. If you can't find it locally, I think you can order it through Amazon. That's where I got mine.
I would love to see what a vat of this stuff would to to a rusty frame. It would be expensive to start, but might even be worth it if you treated a lot of frames.