Photos by yours truley.
The SdKfz 2, better known as the Kleines Kettenkraftrad HK 101 or Kettenkrad for short (Ketten = tracks, krad = military abbreviation of the German word Kraftrad, the administrative German term for motorcycle), started its life as a light tractor for airborne troops. The vehicle was designed to be delivered by Junkers Ju 52 aircraft, though not by parachute. The vehicle had the advantage of being the only gun tractor small enough to fit inside the hold of the Ju 52.
Steering the Kettenkrad was accomplished by turning the handlebars: if little movement was used then the wheel would steer the vehicle, however if they were turned further they would engage the track brakes to help make turns sharper. It was also possible to run the vehicle without the front wheel installed and this was recommended in extreme off-road conditions where speed would be kept low.
The SdKfz 2 was designed and built by the NSU Werke AG at Neckarsulm, Germany. First designed and patented in June 1939, it was first used in the invasion of the Soviet Union in 1941. Later in the war Stoewer from Stettin also produced Kettenkrads under license, accounting for about 10% of the total production.
Most Kettenkrads saw service on the Eastern Front, where they were used to lay communication cables, pull heavy loads and carry soldiers through the deep Russian mud. Later in the war, Kettenkrads were used as runway tugs for aircraft, especially for the Me 262 jet fighters. In order to save aviation fuel, the aircraft would be towed to the runway, rather than taxiing under their own power.
The vehicle was also used in the North African theater and on the Western Front.
The Kettenkrad came with a special trailer (Sd.Anh.1) that could be attached to it to improve its cargo capacity.
Being a tracked vehicle the Kettenkrad could climb up to 24° in sand and even more in hard ground, as long as the driver had courage for it.
Only two significant sub-variations of the Kettenkrad were constructed, and production of the vehicle was stopped in 1944, at which time 8,345 had been constructed. After the war the production at NSU went on until 1949 for agricultural use. Around 550 Kettenkrads were built postwar until 1948 (Some sources say 1949).