In a transmission apparatus for a saddle-type vehicle, dowels on first transmission gears are engageable in and disengageable from dowel holes in adjacent second transmission gears to shift gear positions. The first transmission gears are slidable in response to angular movement of a shift spindle caused by operating a shift pedal. Invalid engagement time, during which the dowels and dowel columns are in sliding abutment, at an idling engine rotational speed is in the range from 0 msec. to 40 msec., providing an enhanced feeling for gear shifting operations and reduce hammering noise.