This little block from Hozan will work wonders on your rim braking surfaces. Being a huge industrial company steeped in metallurgy and machining processes, Hozan understands how to produce products like this to maintain and treat alloys and metals. We do not recommend going to your hardware store and buying a #120 grit sanding block. While the grit texture may be the same, the rubber compound that houses the texture isn't - we have found them to be to harsh on the rim. The Hozan is the only way to go for guaranteed success.
The block is constructed from foamed NBR copolymer-rubber that is impregnated with sintered aluminum dust. The grit is a fine #120 texture which is perfectly suited for removing burrs and refreshing the braking surface on alloy rims. Try it once and you will find that you are using it all the time. If you do not own one, you should.
A few quick passes on your rims and it will remove residue from brake pads, clean and smooth out the surfaces and greatly improve braking performance. The rubberized pad is durable and slightly flexes to conform around the rim surface. One pad will last for while, even with repeated use.