AN ALL-OUT SPRINT: There's nothing more exciting in the world of cycling than that last mad dash to the finish line, the all-out leg clobbering final push that separates the meek from the mighty. Red Bull Bay Climb is a straight line sprint up the historic, near vertical Potrero Hill in San Francisco that promises to deliver those end-of-race moments for all involved. Two categories of cyclists can participate in this event on Sept. 8: Fixed and Open. The Fixed category features a men's and women's division but is restricted to a single gear. The Open category has a men's and a women's division as well and a "run-what-ya-brung" spirit: if you want to ride a fat bike, a mountain bike or something in between, any two-wheel bike is welcome (as long as it's human-powered).
https://www.redbull.com/us-en/events/bay-climb/