Hans J. Pahl is a German automotive engineer, who worked a couple of years as a design engineer with a medium sized company, which specialized in special purpose vehicles - mainly heavy duty trucks for oil fields and airfield fire engins. He worked 15 years in the R&D department and as a product developer with an international company in the automotive supply industry. Since 2002 he works as traffic accident investigator and as an expert for vehicle technology. Hans J. Pahl has been riding motorcycles for 45 years now and since more than 20 years he owns a Yamaha XS 650 with a mileage of about 200.000 miles now.