friendofpugs

This is a bike I picked up cheap for the parts. I thought the frame/fork were toast because of the heavy rust, but I'm now I'm not so sure. Does anyone have any idea what it is? It's Reynolds 531 frame, fork, stays. It has Campagnolo drop outs and fork ends. The parts on it were First Gen Shimano Dura Ace - Crane RD, first gen DA high flange hubs, DA crankset, DA headset, but it had Dia Compe Gran Compe centerpulls and levers, SR Royal stem, and a neat SR Champion bar with dimples that were unfortunately bent. I'm thinking early 70s but I'm not sure what. What there any high end Japanese manufacturer using Reynolds tubing and Campy dropouts back then?

There is no serial number on the BB shell that I can discern, it's pretty rusty. If you want other pictures, please let me know and I'll take them.

Second question - is the frame salvageable? I'm thinking of trying my first OA bath and repainting it.

unterhausen

looks like you should be able to get that rust off and ride it no problem.

I'm guardedly confident that it's a Proteus.

friendofpugs

Oooo, thank you for the reply. I'm glad you think the frame is salvageable. It's one size bigger than I typically ride but I can make it work. Now to go down the Proteus rabbit hole...

bikemig 

This bike is certainly worth your time if you want to do an OA bath and paint job. But if it's one size too large, it might not be worth your effort.

friendofpugs

I know, that's what I was struggling with too. To be honest, I pulled the fork to resell and tossed the frame on my scrap pile but I felt guilty about it and retrieved it a few days later. Just for kicks I've recently been riding a 56cm "French Fit" instead of my usual 54cm and I like the height of the handlebars with the larger frame. Just something a little different, you know?

bikemig 

A lot of times more than one size fits. The top tube may be more important than the seat tube in sizing a bike in any case,

https://www.sheldonbrown.com/frame-sizing.html

But if you don't want to, I wouldn't sell the fork separately from the bike. Someone on BF will buy the complete frame as a project. This is a good frame.

rustystrings61 

Now enquiring minds want to know - what size is this frame?

Last ride 76 

I'll bite. What makes you think it's a Proteus?
I agree that the rust does not look as if it is a structural problem except perhaps the chainstays right at the bridge, maybe.

friendofpugs

The seat tube is 22.5 in / 57 cm center to center, and the top tube is 22 in / 56 cm center to center. With a shorter stem I can make this work, but do I really want another bike?

unterhausen

that's how many of their seat stays were done at the seat lug. This style wasn't that common on bikes that were contemporaneous to this one. And it's very cleanly done and a bit flatter to the seat lug than is normal. Teenage me thought it was a bit sterile.

Other parts fit with a Proteus, but of course they are all standard parts.

madpogue 

Any markings / numbers on the steerer tube?

friendofpugs

I checked pretty closely and got nuthin'.

gugie 

I agree, I used to be wowed by seat stays that were finished off with fancy castings. Now I appreciate the workmanship and attention to detail to nail that miter.