You can get pretty decent rust control primer in the Duplcolor (sp?) brand at most automotive stores. The rattle cans have a fan nozzle and you can lay it on almost as good as a gun...
however...
It ain't the same as using a compressor and a real gun. My whole truck is painted in Zero Rust Safety red, white and black. (White on grill, black on frame) Done last year, sits in the weather and looks fine, except, I used their Crystal Coat clear which sprayed on thin, ran like crazy, and is now hazing up. I can't recommend it even when following their instructions to the letter. Or mebe I am just stupid with their clear, however, the ZR and everything else I have painted came out fine.
Zero Rust does come in rattle cans and I have used it on stuff and it works good. No rust through yet. Also you might also prep before primer with Phosoric Acid (Called Phosphoro, snake oil, etc etc) as it converts/ends rusting. It looks like green water and is fairly mild. Brush on, let dry, wipe with tack rag, shoot primer.
You can also brush or roll ZR on, and it lays down pretty good, but not the same as spraying.
If you are worried about the look of your running gear, I'd get a number of ZR cans of rattle black and have at it. ZR supposedly doesn't like the sun, but running gear rarely sees the sun.
