Why are my brake pads completely eroding after one week I have a CUBE Attain road bike with a Shimano Claris setup. I've had the bike for nearly a year and tracked 1300 miles on Strava. I first changed the original brakes in November at about 900 miles ridden. Since then, I have gone through about 5-6 sets of different brakes. Just last week I changed the whole back brake unit cable and gave the rims a thorough clean. It seemed to work, but now today on inspection the brake pads are worn down and I can see the residue building up. My commute is 3 miles twice a day but only 4 times a week. I'm starting to suspect it's the rims, but I'm not sure. 

What could be causing my brake pads to erode so quickly?
It sounds like you are buying unusually quickly wearing pads. 900 miles is a short distance from a set of brake pads, but 5-6 sets over 400 miles is really excessive.

Personally, I have had very good mileage and all weather performance with Kool Stop Salmon pads. The original pads from Shimano are not particularly good, but not the worst either. There are some other brands that have good reputation, but I haven't tried all of them.