A flywheel assembly comprises a flywheel having a friction surface, a flexible plate, and a stopper plate serving as a stopper mechanism. The above-described flexible plate is flexible in the bending direction and rigid in the rotational direction, and has a radially outer portion fixed to the flywheel and a radially inner portion fixable to an end of a crankshaft of an engine. The stopper plate is for restraining bending deflection of the flexible plate when it exceeds a predetermined amount.