Runner attachment for bicycles with a reaction thrust device

In a runner attachment for bicycles having front and rear axles;

• a runner having a "T" shape in lateral cross section comprised of longitudinally extending angle members, a link attached to the runner to incline from the rear of the runner to a point located directly above midspan of the runner at which point are mounted bearings for attachment to the front and rear bicycle axles, a self-contained reaction thrust device, support member means attached to the inclined link for supporting the reaction thrust device so as to act toward the rear.