An all-terrain vehicle (ATV) has a subtransmission detachably fastened to
an engine casing. The engine crankshaft includes a drive pulley connected
via a belt to a driven pulley in the subtransmission, thus providing a
continuously variable transmission (CVT) between the engine crankshaft
and the subtransmission. The subtransmission includes a 2WD-4WD selector
mechanism to select two-wheel-drive or four-wheel-drive and also includes
a transmission selector mechanism to put the vehicle in park, neutral,
reverse, high-speed drive or low-speed drive. By disposing these selector
mechanisms in the subtransmission, mass centralization is improved
relative to prior-art drivetrains wherein the 2WD-4WD selector mechanism
connects to the front differential. When operating in 2WD mode, the
drivetrain does not waste energy rotating the front drive shaft, as in
the prior art.