I bid on a beautiful Viking racing frame set the other day (lost it, kick! kick! it went for £210 when I would've gone to twice that... I just thought no else was bidding - I'm learning). I don't know if you can see this but I've just dragged a pic from the eBay listing and dropped on this window:
https://cgi.ebay.com/ws/eBayISAPI.dll...ayphotohosting

Anyway, it has chrome chain stays which are in a bit of a nasty state. One thing led to another and I bought a Mercian frame shortly after and searching for info on the make I came across the Mercian website and found they still make frames and have a repair and painting service for old frames, not just their own. It says there that chrome can only be redone on certain types of tubing and the Viking's Reynolds 531 isn't included. Something about the wall thickness being too thin for the polishing necessary to apply chrome. So, it seems that for the Viking the chain stays would have to be either painted or replaced if you wanted them chromed.

I've since noticed that a lot of bikes have chromed chain stays, forks and lugs, particularly high-end Italian stuff and I'm wondering if it's just flash or whether there's a practical reason for chrome.

I don't like it much myself and prefer the deep lustre of multi-coated, good quality enamel paint. Also, being interested in older bikes, chrome strikes me as just another potential headache should it need attention. I'd also think it must be heavier than paint - not that I'd notice, probably.

So, is chrome just for show?

I always liked the idea of a bike whose paint will inevitably chip and gleam instead of rust. Hence the appeal of chrome.

Also, it was used because of chainslap chipping the paint on chainstays.

Some low end Italian bikes used a lot of chrome, too, so don't always assume that chrome = high end.

I like chrome!

I read somewhere that chrome was used on the forks and stays of racing bikes to avoid chipped paint created by hundreds of fast wheel changes over the bike's lifespan, as well as to guard against chain slap damage. Sounds plausible. I just know that it looks cool!

I'm sure there are plenty of nice, rusty bikes you can get for 410 pounds. In fact there are probably some builders who can build you a rust-free frame for that much!

Chrome, if done well, can stave off surface rust. But what often kills frames is rust from the inside. It sure does look nice, and I think the prevalance of chrome on higher-end steel bikes has more to do with showroom appeal than practicality.

Moki:
"I'm sure there are plenty of nice, rusty bikes you can get for 410 pounds. In fact there are probably some builders who can build you a rust-free frame for that much!"

Indeed! When I was thinking about buying a 1976 Mercian frame set I saw that Mercian would sell you a new frame for from about £500. But there's something about riding a bike made 30 years ago. And even something more about riding something that was in a state when you got it but is now beautiful again.

I love chrome. Mostly form but some function.

Chromium oxide is a (more or less) self-limiting type of corrosion, very unlike the ferrous oxide corrosion developed by most high-strength steels -- which just keeps on keepin' on until the steel's gone. Chromium oxide develops passively by contact with air, it's also virtually invisible. Once a thin film forms, it arrests the oxidation of base material below it. Chrome plating is one way to protect steel with this miracle, and stainless steel, an alloy containing a higher percentage of chromium, is another. The problem with chrome, like the problem with paint, is that when it's been breached, and rust begins to form beneath the top layer, it just continues; and in fact, it's an even worse condition that having the steel exposed, because the pockets or bubbles that form beneath the chrome or paint film simply harbor moisture and salts that foment more rust. The same thing can happen with stainless steel in corrosive environments -- if the thin chromium oxide layer is breached, and contaminants prevent the passive "healing" of the protective layer, then it's just not "stainless" any more, and the rust can grow and spread beneath the surface.

Chrome is also very hard, which contributes to its durability. The reason that there are so many bad "full-chrome" jobs is that preparation is everything. The layer of chromium is so thin that, unlike paint, it doesn't fill and smooth out surface irregularities and roughness -- it simply telegraphs them onto the surface. The reason that "brushed" chrome finishes are popular in architectural and hardware applications is that they show fewer defects than bright chrome. And the nomenclature is misleading: the substrate is brushed, not the chromium plating. It's just easier to provide a uniformly brushed surface than a polished one. It's harder to "brush" a bike frame, with its complicated geometry of intersections; which probably explains why we don't see (m)any brushed chrome bikes.

I'm not an expert with plating, but to be the most durable, and have the best finish, chrome is often put over nickel and/or copper platings -- softer materials that somehow improve adhesion of the finish plate to the steel or other substrate (I think you can chrome plate even plastic), and make preparation easier.

I got one. A gaspipe Torpado that I am building into a commuter this winter. It must be the monkey in me, I love shiny things too!

I love chromed frames, especially stays!

The only chroming I dont like which was most frequent in the '80s was when only the right chainstay was chromed (Obviously for chain slap), they shoulda at least did the other side as well, for a sense of symmetry!

I'm not a big fan of chromium plating. While it provides superior protection in certain applications, like the driveside chainstay and dropouts, its cost and risks outweigh the aesthetical component, which is it's prime appeal. It is a very environmentally unfriendly process and the associated probability of hydrogen imbrittlement can reduce the ductility and lifespan of the tubing.

I looked at the Mercian site and didn't quite see that, but this:

"653, 725, 731 and 853 Frames

Please note that we can only chrome the dropouts on these frames. This is because the stays are too thin to be polished for chrome plating."

This isn't quite true, because the stays could be heavily copper plated to build up a base before polishing. However, that's a lot more expensive than whet they do nowadays.

If the chrome on your frame is so bad that it would need replating, the steel underneath is probably badly pitted and in that case there would be precious little metal left if the pitting were polished out. Such a restoration would require building up the metal and polishing. That's done in antique car chrome restoration, but would probably cost more than most bicycle frames are worth.

"and the associated probability of hydrogen imbrittlement can reduce the ductility and lifespan of the tubing." QUOTE

The hydrogen embrittlement is the reason for the 'baking-out', process after plating.

Also may be of interest:

(1) The last, and final step (copper/nickel/chrome) is only about 5 microns thick.

(2) contrary to popular belief, plating is porous, therefor a good protectant is a 'must'. (eg wax or oil)


Regards<
J T

Agreed, 100%. But this a step that is often compromised by platers depending on what they used to plating. Different strengths and hardnesses of steels demand different baking cycles, and even then, baking is still not a guarantee against hydrogen embrittlement, it only reduces the risk.

Your note on protectants is very sound. The plating is still porous, particualrly the chromium.

My bottom line is that plating of frames should be kept to a minimum. And if you are considering having a frame chromium plated, ensure that it is done by someone who has experience with bicycle frames.

T-Mar, I'll give you my address and you can send me any of those awful chrome frames you have taking up space at your place. Especially that ugly red/white one with the chrome stays and lugs.

I love chrome

I'm T-mar's ugly twin brother, may I send you my Ambrosi in it's stead?

Regards,
J T

YUP, tried to send a pic; not only am I UGLY,

I continue to be STUPID as well.

(my pics still don't work!)

Regards,
J T

Maybe your pics suffered from hydrogen embrittlement......

but seriously, on my Tommasini frame the entire frame is chromed underneath the paint. The reason for this was that the process added a certain measure of stiffness and durability to lightweight tube sets like Columbus SL and others back in the day. That was what I read somewhere from an Italian builder in an article on the subject.

...besides, I think chrome is the cat's meow on a bike.

"Maybe your pics suffered from hydrogen embrittlement......" QUOTE.


No, I believe it to be my BRAIN!

(or lack therof)


"Regourds",
J T

No, I have my heart set on the Bottecchia

"No, I have my heart set on the Bottecchia." QUOTE.


Oh well, here I sit, UGLY, STUPID, and can't even give my bike away!

(ROTFLMAO!)


Regards,
J T