All of a sudden my front brake started squealing. I limped it home and took the pads off and behold a rock in there. I took the rock out and put it all back together and no squeal. How often does that happen? The bike has 40 miles on it. It the pad to far from the rim?

If you can can squeeze the lever hard without bottoming it out against the handlebar, your pads are an OK distance from the rim. Picking up road debris in the brake pads isn't common but it happens. More often, rims get grimy and the pads grind it into the rims, causing shards of aluminum to get embedded in the pad.

Keep the bike clean and inspect whenever you suspect something isn't right.

Nada

My disc brakes squeal when wet . Is this normal?