I use a hammer, but most people use a pressurized thingy. It takes a lot of practice but if you put a rag on the inside of the fender and gently bang it out it will look pretty good. After you get the dents out you will find that there is a black outline of where the dent was, it will look like the chrome came off but if you use some chrome polish ( I use turtle wax ) and buff it out a little, it will go away. Like I said it takes practice so dont be mad at me if it dosnt come out right. :roll:
Get a beanbag that is filled with lead shot and a nylon hammer. Just take your time and work slowly. The pressurized thingy bikeguy mentioned is an English Wheel. That would be the best way, but not everyone can be lucky enough to have access to one.
for small dings, a bag of lead shot and a 1/2" drive socket extension. rest the fender on the shot bag and tap it with the drive end of the extension from the inside
why would you want to "fix" a fender dent? The're like scars, they give it some character.
Now if it rubs the tire, or if the bike is for your lady, then use a ball ping hammer and tap it out slowly. Then for painted fenders, sand and bondo, amigo.
I use an old 2" trailer ball as a dolly, and I have a plastic faced mallet that has a slightly convex face, like a bullseye mirror. Works well on chrome fenders.-Adam
I cut a piece of wood to the diameter of the fender, then using course sandpaper wrapped around a good part of the fender, hollow it out till it fits the fender. Then I squeeze it out with some pliers, gently. Another piece of wood carved to fit the inside of the fender and the two fit in a vice would work, too. What ever tools you have access too can be made to work.