If you haven’t seen this video from the latest CicLAvia event, you really should.
Some guy built a super-tall bike, and he rode it from downtown all the way to the Venice Pier. When he goes under the 405 bridge, he claims he only had two inches of clearance above his thumbs on the handlebars.
He had to duck to get underneath it.
You have to wonder what would happen to him if he fell off from that height.
Hope he rides with a helmet.