Nothing kills the look of a bike like chrome parts that have rust on them. If the rust is straight thru the metal, it is already too late. Same thing goes if the chrome as started to flake. But it doesn't hurt to try. A very good friend gave me some fenders for my cruiser and I was half an inch from painting them flat black to match the frame. Then I thought, "Let's see if they would look good all cleaned up" before doing a no-turning-back move like that. If you look at the last pic, you'll realize, I think, that I did the right thing. Here's how I did it:
First you'll need some steel wool, I used a fine one for this job since the rust was not that bad. No need to scratch the metal too hard for nothing.
Second you'll need some metal polish to lubricate, and polish while you rub with the steel wool. Liquid polish works better for me.
Lastly, you'll need a clean rag to buff out everything after you've removed the rust. Mine is pretty dirty, but works great.
Rub the metal-polish-loaded steel wool on the part until you see the brown rust pits vanish. Don't do a circular motion, go in a back-and-forth motion instead to match the length of the part. Circular scratches will show even if they are very small.
Once you've made all the rusty spots go away, take your polishing rag, a clean cotton t-shirt can do the job, and buff the piece until you are happy with the result.
You can always finish with a regular application of metal polish without the steel wool after you're done.
Nicely polished chrome parts will always make any bike look good, even my flat-black-rattle-can painted cruiser. I can't leave this locked anywhere now! It will definitely sleep in the house starting today.
Until next time, ride safe.