Originally Posted by
deraltekluge
A longer crank is effectively a lower gear. You get more torque for same force, while you have to move your feet a greater distance. But the difference between 170 and 175 is less than 0.2 inch. That's a pretty slight difference...can you really tell just by riding, without measuring? The difference in gearing is equivalent to the difference between a 35 tooth and a 34 tooth chain ring.
I concur. See Sheldon Brown's related discussion of "gain ratios."
http://www.sheldonbrown.com/gain.html
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"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069