First you hear the thump of approaching party music. Then a cry from a bullhorn: "Love that right lane, people!"

A loud chorus of energetic shouts: "BIKE PARTY! Yeah!" Ding ding ding go dozens of bike bells ... and a torrent of nearly 200 happy bikers begins to sweep past.

August’s East Bay Bike Party begins at the Lake Merritt BART station (Ninth and Oak streets) at 8 p.m. this Friday, Aug. 13, and features a “Superheroes” theme. Riders and volunteers will be gathering beginning at 7:30 p.m., in costume and ready to ride.