Originally Posted by
rapattack
It's very low level rust to me but the place i did the bike maintenance course recently the guy didn't say anything. There were so many questions i just never got to it. I bought the bike as an ex rental. Should i give it a scour with a wire brush?
Don't bother, that'll just loosen it and turn it into dust which lube will carry into the chain.
Minor surface rust on the outside of a chain is about as important as rust on railroad tracks, meaning it isn't at all. The problem is that you also have some rust on the inside where parts move with respect to each other and that's why it's stiff. Oiling, and some massage will free the link, and if maintained prevent future problems.