A bicycle in zero gravity is unrideable (The bricycle).

Owen Dong, Christopher Graham, Anoop Grewal, Caitlin Parrucci and Andy Ruina Mechanical Engineering Cornell University, A bricycle can be adjusted to be a bicycle, a tricycle, or anything in between. The spring mechanism in the rear provides a restoring force proportional to lean. Using a so called ’zero rest-length spring’, the effective spring constant can be adjusted by moving the attachment point of one end of the spring. Clamping the spring, infinite stiffness, mak