A bicycle trainer including folding legs and a vertically adjustable frame member supporting an axle and cassette where a rider mounts the rear frame, such as dropouts, of a conventional bicycle with the rear wheel removed. The trainer includes a flywheel with a magnetic brake assembly controlled through an open protocol and configured to receive wireless transmitted signals from an app running on a smart phone or other such applications. The flywheel assembly also includes a bracket coupling the magnetic brake with a frame. A strain gauge is mounted on the bracket to detect torque, which is used to calculate a rider's power while using the trainer.