There’s an annual bike ‘race’ in LA each year, riding up the area’s steepest street. Here’s a page recounting the 2007 event. The idea is to get up the hill as many times as you can in a day, with records pushing 100. I can’t imagine the coast back down is that much fun, given how steep it is. The reason I’m posting this is because of this picture:
Checkout the front chainring on that thing. I doubt I could stay upright on that – it would be hard work to keep up with someone walking alongside you without your legs disappearing in a blur.