>>1555389consult sheldon
>An alternative drive system, replacing the chain and sprockets with right-angle bevel gears and a shaft running inside the right hand "chainstay."Shaft drive was briefly popular around 1900, and occasional attempts are made to revive the design. Unfortunately, shaft drive turns out to have more problems than advantages.
>A shaft drive requires heavier frame construction around the bevel gears to maintain their precise alignment under load. The drive system is heavier and less efficient than a good chain drive.>For reasons of clearance, the bevel gears of a shaft drive bicycle must be considerably smaller than the typical sprockets used with a chain drive. The smaller size of the gears causes an increase in the stresses on the whole support system for the shaft. This problem is exacerbated because the stresses from the shaft drive are not perpendicular the triangulated structure of a bicycle frame, and so are not well-resisted. .>Most of the advantages touted by proponents of shaft drive are only advantages compared with open-chain, derailer gear systems. Many proponents of shaft drive use specious (if not dishonest) arguments "comparing" shaft drive systems with derailer gear systems. Any such comparisons are meaningless, it's like comparing apples and locomotives.>A valid comparison of shaft vs. chain drives can only be made if both bikes use the same type of gearing, whether single-speed or with an internal gear system.>These same advantages can be obtained with chain drive using a fully-enclosing chain case, as with old English roadsters and many current Dutch bikes.Shaft drive proponents also often compare sealed, enclosed shaft drive systems with open, exposed chain drive systems. This is also a misleading comparison. All of the advantages claimed for shaft drive can be realized by the use of a chain case.
