Front derailer and composition

[Frinton]

I was cleaning my ride and noticed that a piece of chrome has chipped off of my Dura-Ace front derailer. What is the derailer made of and will it rust?

 

[alfeng]

I was cleaning my ride and noticed that a piece of chrome has chipped off of my Dura-Ace front derailer. What is the derailer made of and will it rust?

The front derailleur cage is generally made of brass which is first plated with Nickel and then Chromium, AFAIK.

The cage won't rust, but there are parts on it which can (e.g., the return spring)

 

[sogood]

The front derailleur cage is generally made of brass which is first plated with Nickel and then Chromium, AFAIK.

I have a similar question. Is it normal for a new derailleur and chain set to wear those Ni-Cr plating? On my new bike, I noticed that after 3-4 weeks, there's plenty of tiny pieces stuck on the chain. I assumed that's all just part of the wearing in process. Or is there something to be concerned about?

Since I've cleaned and re-lubed the chain and I have not seen similar.