The phenomenon of 400-plus cyclists riding past East 4th Street, where diners at Lola and other high-end restaurants have valet-parked their cars, is not something you see every day in Cleveland.But you do see it once a month -- the last Friday of the month, to be exact. That's when Cleveland Critical Mass , a free monthly ride in which cyclists travel en masse through the streets of downtown and other city neighborhoods, kicks off from Public Square at 7 p.m. Riders normally conclude at a low-key tavern, where the revelry continues.The Friday, July 27th Critical Mass event, which coincides with a new, day-long event dubbed Car-Free Friday , promises to be one of the biggest yet. Organizer Shawn Mariani, who works at Parker Hannifin, hopes to best the 500 mark."When I joined Critical Mass in 2008, we had about 5 to 10 people," says Mariani. "Just through word of mouth, social networking and the Internet, we've been able to grow it based on people going out, having a good time and bringing friends."Mariani says Critical Mass is a non-intimidating ride that encourages people to get on their bikes and patronize local businesses in the city. "It's a safe ride and all riders are welcome," he says. "We get people on tandems and BMX bikes, too. It's a way to meet people and see parts of the city you might not see otherwise."This Friday's ride will wrap up at the Cleveland Velodrome. Riders are also invited to check out the Street Repair music festival at East 55th and Broadway Ave.Source: Shawn MarianiWriter: Lee Chilcote