How to clean your rims and brake pads
If your bike is anything like mine then after a couple of bike rides in the rain, the rims and brake pads will be fairly caked in road muck. This greatly reduces braking performance and speeds up the wear on the rims and the pads. To get them clean, the best method is to use [...]
Source: http://www.londoncyclist.co.uk/how-to-clean-your-rims-and-brake-pads/