The 501 was a two-seater scooter, using a light and strong monocoque construction, and powered by a 175cc, two-stroke air-cooled petrol engine.

The engine is kick-started. The clutch runs in an oil bath, controlled by a lever on the left side of the handlebars. There are four gears, controlled by a two-way foot lever on the left side. Operation of the clutch during higher gear change is automatic. The rear wheel is chain-driven. The carburetor make is "Jikov", the spark plug is solex. The rear brake is controlled by a foot lever on the right. The front brake is controlled by the right lever on the handlebars, and is adjustable without tools. The petrol tank holds 12 litres. On top of the petrol tank is a rack for carrying up to max 15kg. Underneath the seat is a lockable cabinet for tools etc and space for the battery. The seat opens forward to lie on the handlebars. A steering lock is located behind the panel in front of the rider.

The handlebars have a diameter of 22mm and length of 660mm. The front suspension has two oil-filled shock absorbers and rubber blocks to limit their movement to 100mm. Each shock absorber contains approx 50cm3 of oil. The rear suspension is spring-loaded, again with rubber blocks to limit travel to 95mm.

The speedometer is on the left of the control panel, and a clock is on the right. Also on the panel are control lights: orange indicates neutral gear; red shows the battery rather than dynamo is being used.

Power to the spark plugs is supplied by a DC 6-volt 45-watt dynamo. A regulator controls the switching of the current from the battery to the dynamo. Extra current generated by the dynamo, charges the battery. The battery is 14Ah, 6V, standard lead-acid. A 15A fuse (standard CSN 72581) is located behind a panel in front of the rider. The headlight has a 6V bulb and 25 watts, the brake light 6V and 10 watts, indicators are 6V and 1.5 watts.

Models:
501 - Series production from 1957.
501/01 - From January 1959, 2,000 produced. Updated carburetor and spark plugs in the motor. Lengthened handlebars to 685mm. A model 501/02 was produced with differences to the electronic systems.
501/03 From March 1959, 16,000 produced and fitted with new axial ventilator. A model 501/04 was also produced, again with a different alternator.
501/05 From approximately October 1959, 25,000 produced Model is fitted with a 12V-90W 'dynamo motor' – a starter motor and dynamo in one.

Read more details about the history of models by following the links in the right column. Owners manuals and other information is also available for all these vintage models in Owners' Guides.