From Bike Tech , October 1983 INVENTIONS

The Bent Crank: Chronology of an Idea

by Harvey Sachs Each year, the bicycle industry produces dramatic and radical advances in technology. One of the most startling of these was the P.M.P. "bent" crank, which outdid even the Gear-Tel for originality. Harvey Sachs, best known for his active leadership in East Coast tandem events, predicts what the future holds for P.M.P. in the following special report:



1981: P.M.P., a small Italian firm, bursts on the scene with the revolutionary "bent"crank, featuring a 90-degree bend in the crank arm. The "L-shaped design increases the pedal's propulsion power and lessens energy dispersion on the downstroke, " according to the manufacturer's literature. 1981: The British magazine Cycling issues a set of P.M.P. cranks to an unnamed first category Surrey roadman for road testing. "Whatever the theories, in practice our roadman tester felt the P.M.P. cranks offered an advantage and surely that is the true criterion," Cycling reported. The roadman himself said, "At low pedaling speeds, dead center seemed to be removed. " 1982: P.M.P. cranks are the talk of the New York trade show. Not many orders, but lots of talk ... (Editor's note: from here, author Sach's chronology dissolves from well-documented factual reporting to crystal-ball speculation.) 1983: Polish Olympic team purchases 20 pairs (mostly 205-millimeter, equivalent to170-millimeter "old-style" cranks). 1984: Soviet Olympic team commissions study by East German Sports Academy to determine extent of functional advantage of new bent cranks. To cover bets, Soviet applied mathematician carries out extensive analysis (256 pp of equations) to optimize shape. 1984: Miyata introduces Shimano AX aerodynamic bent cranks with concave pedals to match. Availability is restricted, and interest is intense. 1984: U.S. Olympic team fails to find sponsor for additional cost of either Shimano or P.M.P. cranks; enters Olympics feeling very discouraged. 1984: Polish national team uses P.M.P. cranks only for climbing stages, relying on the Surrey Roadman's report that they "helped me keep a steady rhythm particularly when sitting back in the saddle and climbing hills." 1985: Bikecology, Lickton's, and BikeNashbar introduce the components to American amateurs - at $178, plus rings. Delivery time, 6-8 months. 1985: Richard Jow gives equivocal evaluation in Bicycling - but uses nice test jig. 1986: Huret joins forces with Maillard to introduce patented recurved (S-shaped) crank for track bikes. Claimed to give equally significant advantage when sprinting or standing. Helicomatic: design gives rapid disassembly with a single lightweight wrench (supplied), and recurved design makes it easy to convince the user that the arms are really 180 degrees out of phase. 1988: Polish Olympic team uses straight hollow titanium cranks. Soviet team, on basis of 256 pp. analysis, bolstered by information from East German Sports Institute, introduces the CCCP bent crank - bent to the left instead of the right, of course. 1989: Bikecology sells their only three pairs at warehouse sale for $37 per pair. BikeNashbar offers remaining three (right only, 43/54, 205 millimeter, Italian thread) for $78. 1992: USCF's famed Elite Athlete Program completes study on the most efficient pedaling motion in the history of cycling; concludes that P.M.P. cranks are the way to go. Purchases the last available P.M.P.cranks at collectors' item prices (rumored tobe $500+ per set). Technical Director Ed Burke is ecstatic. Other equipment sponsors (Campagnolo, SunTour, etc.) are perturbed by large cash outlay. 2013: MIT engineering professor finds P.M.P. crank in back room of The Bicycle Exchange, and carries out strain tests to see if it really did make a difference.

