A scooter device having a flexible, tiltable frame structure and biased direction rear wheels. The scooter may be of a type that achieves forward propelled by side-to-side movement of a user. The frame structure may include a flexible member or members and/or incorporate other flexible or moveable components to achieve desired performance. The frame structure and steering mechanism may be moveable into a more compact form for storage or transport. A brake arrangement and other features are also disclosed.