http://www.rei.com/category/4500003 Dan, an REI Outdoor School instructor, demonstrates a quick pre-ride bike inspection in this video. Follow the ABC's checklist. A = Air: check your tire pressure—while you're at it, check that both quick-releases are securing your wheels safely to the frame. B = Brakes: Check that front and rear brakes engage properly. C = Chain: Check that your drivetrain is clean and lubed.