BMW R 24

Engine

Extremely compact one-cylinder four-stroke engine of 12 HP(continuous operation). Moximum speed 5,600 r. p. m. Economy-minded design of combustion chamber due lo beautifully shaped, generously dimensioned light metal cylinder head with large-surfoce cooling finsand efficient dissipation of heat. Overhead valves arranged Vee-wue in cylinder head; entire valve gear assembly encased for protection from dust and dirt. Light metal piston with two rings and one oil control ring. Crankshaft supported by ball bearings; steel connecting rod with roller bearing, fitted with roller cogt. Single-valve carburetter with large air filter.

Chassis Frame

Distortion-proof, twin steel tubular frame, en-bracing the engine. All frame joints are double bolted or welded. The tolescopic front forks are permanently oil-lubricated, saddle comfortable cushiony springing. All moving ports are corefujy protected from dust and dirt, this making for reduced fork maintenance. On the handlebar center, eyes have been provided which make it possible to lock the motorcycle. Ihe graceful sodcletankof 12 liter* (2.65 Imp. gall.; 3.2 US gall.)copocity has quick action filler cap, builtin tool kit, and rubber pads. Both front and rear whees have push-cut axles, this making for easy assembly. The generously dimensioned internal shoe brakes result in short stops.

The convenient vlaguratype handlebar has a twist grip throttle and easy to operate. A steering damper has not been forgotten. Ignition timing is self-adjusting. Large, easily dimmed headlight with integral peedometer and ignition lock. A 6-volt, 60-watt storage battery installation takes care of ignition and satisfactory road lighting, the soft spring rubber saddle with its large sitting surface contributes to relaxed riding. Tyre size 3" x 19".

Transmission

Efficient transmission of power is guaranteed by 3 long-life, generously dimensioned oil-free single-disk clutch. The heavyduty, carefully designed four-speed gearbox is bolted to the engine. Easy gear shifting in both directions is obtoined by convenient, easy-to-operote, foot gear change. The transmission ratios are: 1 st gear 6.1 :1; 2nd gear 3011; 3rd gear 2.4:1; 4th gear 1.54:1. -The gearbox-to-rear-wheel transmission ratio is 4.18:1. - Power transmission from gear box to rear wheel is obtained by time-tested, durable universal-joint shaft. All ports susceptible to damage are completely protected from outside interference. Smooth and shock free transmission is obtained by an elastic drive shaft in the gear box and a rubber-sprung clutch inserted in the universal-joint shaft.