I recently bought a Trek Bontrager 1.1 from my LBS. I've ridden a lot and ive had this problem twice before and twice today. i get a grinding with my brakes and metal shards are visible on the tops of the pads. I had the problem with the front then back. Today it was my front twice. The first time today i ran it down to the shop and he said it happens to his a lot (also tuned everything up. Very helpful) But after i left, about 5 minutes later, it was doing it again. He told me to clean it with an Xacto knife if it does it. I was wondering if anyone knows why this happens or if they have this probem and have any other advice

Change your brake pads. Some pads work with some surfaces and others just grind off the braking surface turning your brake pads into 1 grit sandpaper. Go with Kool Stops. They seem to have a good track record.

It's common. Some rims and brake pads do it more than others.

I take the pads out every once in a while and pick the shards out with a small screwdriver. It doesn't take long. You can even leave them in the brake if you are lazy.

Good brake pads, clean rims (with alcohol) and pick shards out of the pads, will likely solve the problem. And fyi, i use a dental hygienist tool to pick crap out of my brake pads as opposed to a screwdriver. I find screwdrivers too dull and blunt.

Welcome to riding on aluminum rims.

As a part of braking the rims will in fact be "eaten" up by the pads. Different pads work differently with different rim materials. Pretty specific eh? You will find that when riding in wet conditions the wear and corresponding "scrapping" sound gets worse. As others mentioned - try different pads, clean your pads and rim surface. If it continues and you don't like it ...well...then you're doing something wrong.

I love it when newer riders obsess over normal things and see them as something truly out there as some sort of huge flaw. It takes me back.

+1 to getting better pads. Most low to mid range road bikes come with generic brakes. The calipers aren't all that bad, but the pads suck. That's the first thing I replaced on my most recent bike purchase.

Replace your brake pads. Kool-stops are awesome. Inspect and clean as necessary.

Check to see if there is any sand or grit on the pads. That stuff seems to be hard to get out once embedded and seems to grind more on the rims than metal shards.

Hate to sound like a broken record. Change your pads, Kool-stops.

Any particular kind of Kool-Stops you guys reccomend?

Depends on the conditions you ride in. Salmon are great for rain, black are good for dry, and mixed are a compromise between the two. Many of my friends prefer the mixed because they don't feel any loss of braking in the dry, they are clean and brake well in the wet, and if they wear out faster, they can't tell.

Thank you very much. How much do they usually run? I glanced on their website and cant find prices

Or you could just buy some Dura Ace pads

I use the dual compound Kool Stops. They work great and have lasted me over 3000miles(Still going!). Cost around $7-10 for one pair and you need two pairs for your bike.