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Old 10-04-21 | 02:28 PM
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verktyg
verktyg
 
Joined: Jul 2006
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From: SF Bay Area

Bikes: Current favorites: 1988 Peugeot Birraritz, 1984 Gitane Super Corsa, 1980s DeRosa, 1981 Bianchi Campione Del Mondo, 1992 Paramount OS, 1988 Colnago Technos, 1985 RalieghUSA SBDU Team Pro

Chrome Plating Cracking

Originally Posted by gugie
Not quite sure what everyone's thinking here, but the thickness of chrome is insignificant to the thickness of the chainstays, there will be no measureable difference between the force required to cold set a painted vs a chromed frame.

The one issue might be that the chrome cracks. I've had that happen on poorly chromed forks while reraking. The chrome in tension is "stretched" and can crack, even pop off in small sections.


There are several different types of chrome plating that can be used on a bike frame:

Triple plating is superior in most applications. It's not 3 layers of chrome but an initial layer of copper which fills in surface imperfections and is then polished. The second layer is nickel plating which give a harder surface for the chrome plating to build up on. It's sometimes polished too. The final layer is a very thin coating of chrome from 0.0002 to 0.0006 in. (from 0.005 to 0.015 mm). The chrome itself is very hard and brittle, 70Rc to 78Rc.

Double chrome plating is more common and less expensive. The copper layer is skipped and it's just nickel and chrome. The nickel doesn't adhere as well as copper plating to the steel. Bending a plated surface causes the nickel to loose adhesion and eventually crack or peel off. The damage may not appear right away.

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