Before you move your bike down to the basement this winter, go visit Ray Petro. He's created a monstrous wooden obstacle-course for mountain/BMX riders in the bowels of a West Side warehouse complex. Since opening last year, Ray's has already gained national attention in Dirt Rag magazine. Soar off box-jumps, fly 'round the 12-foot berm, and teeter white-knuckled across skinny log bridges, some as high as five feet off the ground. Make sure to bring knee- and elbow-pads, as the concrete floor is a bit less forgiving than dirt.