The 1909 Harley-Davidson V-twin was Harley's first production V-twin. By this time, gray had replaced black as the standard color, and Sager-Cushion front forks were used that allowed a small amount of front wheel travel. Cylinders were the same size as those used for the single, displacement coming out to 49.48 cubic inches. The "V" measured 45 degrees -- as have all street Harley V-twins since.
That first V-twin didn't fare well, however, one problem being that the drive belt lacked any means of tension adjustment other than to move the rear wheel. The V-twin was withdrawn from the market for a year, and when it returned for 1911, it had mechanical intake valves and a belt-tensioning device. The following year, displacement was increased to 61 cubic inches.