Campagnolo crankset dating
Cold forging gives the metal additional strength, and the cranks can therefore be made lighter without increasing the risk of breakage.Shimano "Hollowtech" aluminum cranks are made by forging the main arms around a hard steel insert which is then withdrawn, leaving an internal void to save weight.
Composed of assorted mixtures of aluminum, copper, graphite and nickel powders in a grease base, such lubrication allows repeated assembly and disassembly without wear and the elimination of fretting corrosion during use.As there is no chainwheel on a unicycle, right and left cranks are identical, except for the pedal attachment thread in the left-hand crank, which is reverse threaded.Cranks are constructed of either an aluminum alloy, titanium, carbon fiber, chromoly steel, or some less expensive steel.Larger wheel diameters (26" to 36") require longer cranks, as do disciplines such as Mountain Unicycling, Trials, Street, and Flatland.
These unicycles and disciplines commonly use cranks lengths greater than 125mm.
A solution, suggested by Jobst Brandt, is to use a 45 degree taper at the surface where crank and pedal meet, as this would eliminate precession-induced fretting and loosening (it is already done for most automobile lug nuts for the latter reason).