Sport touring motorcycle sportbikes were redefined (for marketing purposes) as sport touring bikes: the 2000 Kawasaki ZX-6R sportbike became the 2004 ZZR600 with just a change to a fairing bracket. Sport touring motorcycle A sport touring motorcycle (sometime a "sports-tourer") is a type of motorcycle that combines the performance of a sport bike with the long-distance capabilities and comfort of a touring motorcycle. The first sport-tourer is said to be the fully faired 1977 BMW R100RS. Journalist Peter Egan defines the sport-tourer as a "café racer that doesn't hurt your wrists and a touring bike that doesn't feel like a tank," and identified
Propeller (aeronautics) for Aeronautics (NACA) was directed by William F. Durand from 1916. Parameters measured included propeller efficiency, thrust developed, and power absorbed. While a propeller may be tested in a wind tunnel, its performance in free-flight might differ. At the Langley Memorial Aeronautical Laboratory, E. P. Leslie used Vought VE-7s with Wright E-4 engines for data on free-flight, while Durand used reduced size, with similar shape, for wind tunnel data. Their results were published in 1926 as NACA report #220. Lowry quotes a propeller efficiency of about 73.5% at cruise for a Cessna 172. This is derived from his "Bootstrap approach"