Pro Stock Motorcycle Pro Stock Motorcycle Pro Stock Motorcycle, formerly known as Pro Stock Bike, is a motorcycle drag racing class that is the two-wheeled equivalent of Pro Stock. It has been a feature of NHRA drag racing since the 1980s when it was added to the professional class structure and has since spread around the globe. The first points championship season was the 1987 NHRA season. The class has for years been dominated by inline-4 cylinder Suzuki based bikes but in recent years Harley-Davidson based V-twin machines have become more competitive due to favorable rule changes (160 c.i. Harleys vs. 107 c.i
Tornax Tornax Tornax was a motorcycle manufacturer in Wuppertal, Germany. Tornax built its first motorcycle in 1926. This was the model I-26, which has a 600 cc single-cylinder side-valve engine imported from JAP in London, England producing 15 bhp. For the remainder of the 1920s all Tornax models featured side-valve and overhead valve (OHV) JAP engines of 500, 550 and 600 cc, apart from the V-28 in 1928 whose 600 cc side-valve engine was supplied by the German engine manufacturer Columbus in Bad Homburg. In 1930 Tornax produced its first twin-cylinder model, the III-30, which had a side-valve 1000 cc V-twin