It’s finally bike-riding season---at least for those of us who need fair weather to hit the bike lanes. And if you’re looking to tune up your bicycle, or just want to learn about some preventative measures, it’s also time to sign up for a bike-maintenance class. Next Thursday, REI is hosting a free Bike Maintenance Basics course from 7 to 8:30 p.m. They’ll show you how to handle some quick fixes, like lubing chains and fixing flat tires, but these classes are always popular, so sign up early. (Thursday's holds 108 people.) Bonus: The Bike Depot is also starting up its Mechanics Classes, which will take place on Wednesday nights, running from around 5:15 to 8 p.m. Classes range from tune-up lessons to focused sessions on derailleurs, brakes, hubs, and wheels. Call 303-393-1963 for more details.