From 1955 to 1959 Harley Davidson produced a two stroke single cylinder low displacement motorcycle called the Hummer which was based upon the German DKW RT125. The same design was also passed to the British who then produced the similar looking BSA Bantam and the Soviet Union produced the MMZ M-1A Moskva or more commonly referred to as the Minsk.
Although he Hummer was a specific motorcycle type, the name Hummer was later associated with all small displacement engines and motorcycles produced by Harley Davidson from 1948 until 1966.
Below is a list of motorcycles from that era.
Model S-125 : 1948 – 1952
The S-125 or Model 125 produced as as 47 year but released as a 48 year motorcycle. It had a 125cc two stroke engine, 3hp, 3 speed foot changing gearbox. The front suspension was of the girder fork type suspended by large rubber chords which were prone to breaking and were unavailable from the early 60s.
The was a two up version of the bike but was rather underpowered, hence did not sell well. In 1949 the motorcycle had a 6v electrical system with early bulb and reflector headlight.
10,000 bike were sold in 7 months of 1947 and whilst dealers did not care for them, they appealed to younger riders for their efficiency and economy. The rubber chord suspension was replaced by telescopic forks in 1951 known as the Tele Glide
Model 165 : 1953 – 1959
The Model 165 succeeded the S-125 in 1953. The engine was increased in size to 165 cc.
Hummer : 1955 – 1959
The Hummer was the next addition to the Harley-Davidson’s model range in 1955. It was a simpler basic model using a redesigned “B-model” engine with the old 125 cc capacity. It was named after Dean Hummer, a Harley dealer in Omaha in Nebraska who was the leading salesperson in the national Harley two-stroke sales.
The Hummer had magneto ignition and was sold without battery, electric horn, turn signals, or brake light. Bare bones as it came.
Super 10 : 1960 – 1961
The Model 165 and the Hummer were both replaced by the Super 10 in 1960. The Super 10 used a 165 cc version of the “B-model” engine previously used in 125 cc form in the Hummer.
Ranger : 1962
The Ranger was an off-road Harley-Davidson motorcycle without lights, made only in 1962. It had an extra-low final-drive ratio of 7.0:1 12-tooth countershaft gear and 84-tooth rear sprocket with neither lighting system nor front fender. It is believed to have been built to consume their supply of 165 cc engines, which would not be needed for their other models.
Pacer : 1962 – 1965
The Pacer was the replacement for the Super-10. It used the newly enlarged 175 cc B-model engine.
In 1963, one year into production, the frame of the Pacer was heavily redesigned. The new frame incorporated rear suspension through an “L”-shaped swingarm that actuated a spring mounted horizontally under the engine. The seat and rear fender were supported on a subframe bolted to the main frame.
Scat : 1962 – 1965
The Scat was a dual purpose motorcycle based on the Pacer. It had a high-mounted front fender, high handlebars, softer springs supporting the seat, a “scrambler” style high-mounted exhaust pipe, and street-legal off-road tyres. The extra-low final-drive ratio of the Ranger was available on the Scat as an option. The Scat also received the Pacer’s new frame in 1963.
Bobcat : 1966
The Bobcat was the last of the RT125-based Harleys and the only one offered in 1966, its only year in production. Based on the ’63-’65 Pacer frame, it had ABS resin bodywork moulded in one piece that covered the tank and the rear tire and supported the seat. It was the only RT125 based Harley with a standard dual seat.