A continuously variable transmission as a speed change unit is inclined such that an upper portion of the transmission is displaced more than a lower portion of the transmission toward one side in a lateral direction of a vehicle body. Thereby, a space on the other side of the upper portion of the transmission in a vehicle body frame is enlarged, and a muffler is arranged in the space. The vehicle body frame may an inverted trapezoid shape, when viewed in a longitudinal direction, with an imaginary line connecting upper ends of left and right vertical frames as an upper base and an imaginary line connecting lower ends of the vertical frames as a lower base. Inside the trapezoid, a longitudinally oriented long muffler is arranged in a vicinity of one of the upper left and right corners of the trapezoid.