Thor Model U
Thor Model U was a motorcycle that debuted in the 1910s with a 7 hp V-twin in the Thor marque of Aurora Automatic Machinery Company of Illinois. The 1913 model came with a 61 ci V-twin engine, with the V at an angle of 50 degrees. In 1914 the engine size was increased from 61ci to 76.25ci The motorcycle had chain drive with clutch and was overall a bicycle configuration with two handle bars and seat above a frame which housed the engine and connected the front and back. The V-twin has an angle of 50 degrees. By 1916, the Model U was essentially the "flagship" of the Thor lineup with a large 50 degree V-twin with mechanical valves, a magneto ignition, and a three speed transmission. These kind of features were improvements over typically features of the day like a single-cylinder engine, battery start, and two speed or even single speed;they were much closer to their bicycle origins they had just birthed from in the previous decade.