They offer bicycle training wheels.Serious training wheels for bikes. Built by an industrial machine design company, Fatwheels are rugged and long lasting and use heavy duty pneumatic tires just like those on a bicycle. Fat Wheels can be used only on bikes with solid rear axles. (Bicycle not included.) Even though Fatwheels add great stability to a standard bicycle, we do not recommend the use of foot pedal attachments or other restraints on any bicycle. Always wear a helmet and appropriate protective gear while riding.