SPEED-CHANGING DEVICE

A control value is corrected and learned based on a difference angle Δϕ between a drum shaft conversion spindle integration angle ϕs obtained by converting a detected spindle angle detected by a spindle angle sensor 78 into a drum angle and a detected drum angle ϕd detected by a drum angle sensor 89, over a predetermined learning time T from when the shift motor 61 is driven, and a drive engagement portion 83d of a shift driven gear 83 reduces the play angle to abut on a driven engagement portion 82d of a drum center 82 to accompany the driven engagement portion 82d. In this manner, rotation of a shift drum 80 can be accurately controlled by the shift motor 61, while the number of components of a variable speed drive mechanism 60 is reduced.