cudak888 

Factory chrome job or later?

-Kurt

cudak888 

Because there's more than enough evidence from the other chromed frames in the shop that both shop and chromer don't seem to be beneath hack work.

Just so happened that this one and a few others seemed to be pretty well executed.

-Kurt

ascherer 

All indications are that it was chromed later. Seems like the Mark I was only produced in white with Ruberg stripes even though earlier incarnations had chrome socks. I got the frame on the Classic Rendezvous list, 1970 "E" Serial. It had a Turin shop sticker on the head tube covering the holes from the original headbadge. The previous owner (not original) knew some people who knew some people that contacted the owner from the era to ask if they remembered anyone having them send out a Mk. I for chroming, but nothing came of it. It's a well-executed job. Smooth, slick, hardly any flaws or signs of wear or discoloration. A Raleigh Anniversary headbadge fit perfectly in the holes. It's a great frame, from the first ride it felt familiar as if I'd had it since new.

Bad Lag

Ack!, yours is a great frame - one of my all-time favorites when in mink blue and silver.

Your chrome plated frame looks fantastic, too. From what I can see in the photos, it looks as if some care was taken.

If I find some time, and if I remember, I will do more research on annealing hydrogen embrittlement. I have more resources at my employer. I might even be able to talk to some plating specialists. We have a cadre of PhD materials scientists & engineers who's work supports the plating shops.

It surely would be nice to be able to ride it with confidence, no?

I do not want to get your hopes up but if I get some info, I will pass it along to you.

Steelman54 

FWIW, the higher the strength the more susceptible the steel is to hydrogen embrittlement. Reynolds 531 or Columbus SL are not high strength steels. A quick search shows 531 has a yield strength of ~50 ksi and a tensile strength of ~130 ksi. This is less than HRC 30 hardness and the steel is highly ductile. Generally below HRC 30 the susceptibility for hydrogen embrittlement, though not zero, is not considered high risk. Certainly for high stress applications (i.e. aerospace) baking would be required and if memory is correct, bake is built into the AMS plating spec (don't quote me on this one). I don't know anyone that works/worked in a production bicycle manufacture environment so have no idea if they would require a bake or not. I'll bet they didn't always do it, if at all, but that is just a best guess. Certainly something like 853 would require baking as its strength is significantly higher than good old 531 or SL.

You could bake the frame and fork at 325 F for a couple of hours, the chrome may oxidize a bit (start to turn blue), but can probably be buffed out, if it make you feel better.

Overall though the risk isn't zero, but it isn't that high, so I'd build and ride as it seems like the bike shop used this chrome plater for years.

Also inspecting for cracks is hard as this is not a fatigue type of cracking, that is crack initiates and grows relatively slowly (though I would as others have said carefully look at the bottom bracket shell and fork). When it cracks it just cracks or pops, which doesn't mean it breaks into 2 or 3 pieces and you crash.

Just some thoughts on steels and chrome platting and risk.

cudak888 

Fair enough. I'll build it and cross my fingers that the BB doesn't decide to get a hairline crack someday.

-Kurt