Patent ID: 8647241

Claim:
A supine cycling exercise machine comprising: a frame, disposed on a horizontal base; and a rotation driving assembly supported by said frame, said driving assembly comprising a rotatable crankshaft extending through a sprocket wheel, and two crankarms with proximal ends thereof attached to opposite ends of said crankshaft and distal ends thereof attached to two pedals; at least one end of the crankshaft having two grooves on circumference of the crankshaft, disposed opposite each other, each groove in perpendicular to a longitudinal axis of the crankshaft; at least one crankarm having a quick-release hub at a proximal end thereof, with said at least one end of the crankshaft disposed in an axial bore of the quick-release hub; the quick-release hub having a quick-release pin engaging with one or the other of said two grooves on the crankshaft, thereby locking said at least one crankarm onto the crankshaft at either an opposing or a parallel orientation relative to the other crankarm, thereby said exercise machine enables two different cycling exercises.