wild pigs n. poorly adjusted brake pads that squeal in use.

From the Dictionary of Mountain Bike Slang

If you suffer from wild pigs there are a couple of things you can try. First, make sure the pads are aligned correctly and angle them so that when the brake is applied the front tips touch before the backs. To put this another way, if the wheel is rotating this way: ---> the pads should be angled like this \ but shallower.

Next try cleaning the rims and pads with a non-metal scouring pad and rubbing alcohol or bike degreaser. If you pads are fairly old, or you do a lot of riding in the mud, you might need new brake pads. You could also try sanding the rims with a medium emery cloth, which will remove built up crud and roughen the braking surface. If you have linear pull brakes a brake booster might also help by increasing the power of the brakes.

If you have any questions about wild pigs, or any other bike related topic visit everything2 and your local bike shop/mechanic.