Fluidride's Flow-Tonic Mountain Bike Instructional DVD. This DVD Follows the successful Mountain Bike instruction DVD, Fluidride: Like a Pro, veteran pro racer and internationally renowned coach Simon Lawton discusses the importance of proper footwork on the bike. “if I could bottle flow, it would smell like dirty socks,” says Lawton. Flow-Tonic teaches you the importance of riding from your feet in any riding discipline, and gives you easy and clear ways to start your very own riding revolution.