THE BEST MOTORCYCLES
cool classic cafe racer, a classic bevel-drive… probably modified from a Darmah.
Bevel-driven cams use a series of 45-degree angle meshing gears and rotating shafts to transfer half-speed rotational motion from the crankshaft’s RPMs, to the camshafts above the valves in the cylinder heads.
Gear drive, belt drive, and chain drive, or a central camshaft with pushrods to the cylinder head, are more commonly used than bevel gears and rotating shaft driven cam timing.
Usually the other cam timing mechanisms are less maintenance intensive than keeping the proper gear mesh and shaft bearing play runout measurements in check, as well as keeping the valve train clearances maintained also.
The bevel drive engines are nice to look at, though, as an intricate operational machine.