I'm fairly new to mountain biking and I was able to put in around 900 miles on my first set of brake pads on my Giant Anthem X2. At that point they started grinding metal on metal. I went and bought new Shimano pads (I have Shimano brakes) and after only 100 or so miles one of the front ones has already worn out.
The last time I rode the bike was in rain and mud so I'm not sure if that contributed to it.
How long do the brake pads typically last? Is there something else going on?