2008 Big Dog Motorcycles Mastiff, 2008 Big Dog Mastiff - Features on this nice bike include: 300 mm rear tire; 2 into 1 loud exhaust system; S&S motor with fuel injection; 6 speed transmission; nice all black gloss paint. Comes with 30-Day Unlimited Mile Powertrain Warranty and Wholesale Buyback Guarantee. Big Dog Motorcycles is an American manufacturer based out of Wichita, Kansas. Established in 1994, Big Dog was one of the world's largest manufacturers of custom motorcycles. Every Big Dog bike features a V-Twin 117 cubic inch engine, 6-speed transmission, one-piece steel tank and right side drive, but what sets Big Dog apart is customization.