I use 0000 steel wool or bronze wool (when I can find it) on my steel wheels and if there is any chrome left it will clean right up. I also use a small brass "tooth" brush to get in around the spokes. Some people use a bit of oil with the steel wool. This works very well on the older chrome wheels, like on the old Raleighs and Schwinns. Mainly pre-1980. Once the chrome went offshore to the pacific rim the quality really took a nose dive and doesn't seem to clean up as well.

Aaron