For nearly 80 years, shaft-drive boxer twins have traditionally formed the backbone of the BMW motorcycle line-up. For many enthusiasts of the Bavarian marque the classic BMW twin was the R90S of 1973-76. Over the decades, successive generations of durable machines - including the R100S, fully-faired R100RS, four-cylinder K-series, high-performance R1100RS, and an entire family of touring and sporting models ranging from 850 to 1200cc - would ensure the BMW boxer twins a place in the popular Haynes 'Great Bikes' Series.