The Nimble helmet protects both the rider and his or her bicycle. It allows for a quick and easy bike-locking solution for the many stops an urban rider makes in the course of his day. By placing the helmet on the down tube of the bicycle frame, and inserting its cable through the rear wheel spokes and back to the helmet, the Nimble helmet locks the wheel in place, thus protecting the bike and conveniently storing the helmet in one easy click.