Sport touring motorcycle 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 the R100RS as the first example he owned. Unlike a sport model, a sport touring model will typically have more wind protection with larger fairings and an
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"