I commuted for over a year now in NYC with BB7s, 8 miles each way, year round, in any weather (skipped few days), plus errands and weekend rides and I haven't used up one set of BB7 pads that came originally with my brakes yet (I got them in December 2009). They look like just over 50% used up, and these are not even the metallic type, but just the regular organic pads that come with the BB7s. So that's like 6,000-8,000 miles. For an average commuter (10-20 miles/day, mostly flat) they should last over 10,000 miles, that's 2-3 years. This will of course vary: how hilly your ride is, how heavy your bike is, weather conditions and road conditions (sand and dust will wear them out quicker), etc. The rotors will last a decade