If you've got a bike and a free day this weekend, get pedaling to the Mission Bicycle Festival. It's a two-day celebration of all things two-wheeled that kicks off on Saturday with a three-mile ride from Mission Bicycles at 776 Valencia to Golden Gate Park's Tour De Fat.

The Tour De Fat, brought to us by the New Belgium Brewing Company, is an epic bike worshipping bonanza, and organizers encourage those who come to "dress in your favorite alter ego."  At 11 am, the parade starts its procession in Lindley Meadows (you can register there at 10 am), followed by a car/bike trade. What's that? It's when a brave soul actually hands over their car, keys, title and all, to the Tour De Fat altar in exchange for a fully-loaded New Belgium hand-crafted commuter bike. If you've got the cojones and a car to give, sign up here.

At 2:30 pm, organizers will stage a funeral procession for whatever car is sacrificed to the Tour De Fat altar, followed by an all-out celebration. They're serious, folks.

Once you've recovered from all the car-hating, Sunday is a day to hang loose. There will be a free bicycle block party at the Women's Building on 18th Street, starting at noon. Participate in bike polo, bunny hop and trackstand competitions. Eat free pancakes from Chrome Bags and take a ride on the Conference Bike (whoa). There's more too, so check out the full schedule here.

The Women's Building will also host a Mercado for artfully and locally crafted bike gear, featuring more than a dozen vendors, like Mission Workshop and Skully Boom. A bike fashion show will follow at 4:15 pm, complete with bikes on the catwalk.