I went to LA to visit some friends and took part in their Critical mass ride that started at Western and Wilshire. It was a large colection of fixies and a very fast paced ride. Much different from Chicago's. We rode for almost an hour before a cop car made us get off the streets since we "were blocking traffic". We went to a city park and waited about 20 min before starting back on to the street again. It was different yet still tons of fun.