|Assembly||Milwaukee, Wisconsin, USA|
|Engine||10 cu in (164 cc) 2-stroke single-cylinder engine with reed valve|
|Bore / stroke||2.375 in × 2.281 in (60.3 mm × 57.9 mm)|
|Top speed||46 mph (74 km/h)|
|Power||9 hp (6.7 kW)|
|Transmission||continuously variable transmission, between 18:1 and 6:1|
|Brakes||Front and rear: 5 in internal expanding drum|
|Tires||4.00 x 12|
|Wheelbase||51.5 in (1,308 mm)|
|Dimensions||L: 75 in (1,905 mm)|
W: 24 in (610 mm)
H: 37 in (940 mm)
|Seat height||30 in (762 mm)|
|Fuel capacity||1.7 US gal (6.4 L)|
Design and specifications
The Topper had a 165 cc (10.1 cu in) single-cylinder two-stroke engine mounted horizontally between the floorboards. The engine required a premixed gasoline/oil mixture. The starter was of the rope-recoil type similar to lawn mowers or the Lambretta E model. Unlike most scooters with enclosed engines, the Topper's engine did not have a cooling fan. It was expected that the low, horizontally mounted engine would be cooled by air passing under the scooter, but some Toppers developed overheating problems. The engine used a reed valve in its induction system.
The engine powered a continuously variable transmission called "Scootaway Drive" that included a safety device that did not allow the scooter to move from rest at engine speeds higher than 1800 rpm. Final drive was by an exposed roller chain.
The Topper had 5 inch internal expanding drum brakes on both wheels. The front brake was controlled by a hand lever on the left handlebar with a parking brake lock; the rear brake was controlled by a pedal.
The front body, front fender and floorboards of the Topper were made of stamped steel, and the engine cover and body were made of molded fiberglass. Storage space was provided under the seat; the manufacturer suggested storing extra containers of two-stroke oil there.
The main complaint from Topper owners was with the "Scootaway Drive" continuously variable transmission. Road grime would get into the transmission and cause the belt to slip. A new transmission, with the primary drive sealed in an oil bath, was introduced for 1961.
The Topper H was introduced in 1961 (sold through 1965) with a new alloy cylinder head that increased the compression ratio to 8.0:1, a reusable foam air filter, and revisions to the cylinder ports and air intake tube.
A detuned version of the Topper was also available, with the power restricted to 5 hp (3.7 kW). This was advertised as the "Topper U". The detuned Topper was made to comply with laws in some states in the United States that allowed motorcycles with rated engine power below a stated maximum to be operated without a license or to be operated on a special license by riders at a younger age than would be allowed a regular motorcycle license.
In 1959, a Topper was ridden from Bakersfield, California to Death Valley and back without repair or adjustments requiring tools. The route went through Trona, through the Mojave Desert to Stovepipe Wells, on to Badwater Basin, the lowest point in North America at 282 ft (86 m) below sea level, then to Whitney Portal, 7,851 feet (2,393 m) above sea level on the side of Mount Whitney, after which it returned to Bakersfield.
- Zündapp Bella – a German scooter with similar front suspension and cooling system
- List of motorcycles of the 1950s
- Wright 1987, p. 84.
- Arctander 1959, p. 65.
- Ismon 1959a, p. 14.
- Ismon 1961, p. 18.
- Dan 2007, p. 138.
- Wood 2004, p. 67.
- HD 2015.
- Arctander 1959, p. 64.
- AECG 2007.
- Lambretta Model E - Lambretta Club of Great Britain
- Ismon 1959a, p. 13.
- Ismon 1962, p. 13.
- Hicks 1961, p. 229.
- Ismon 1959b, p. 35.
- Arctander, Erik H. (June 1959). Allaway, Howard, ed. "New U.S. Scooter Shifts for Itself". Popular Science. Popular Science Publishing. 174 (6): 64&ndash, 65. ISSN 0161-7370. Retrieved 2012-07-25.
- Dan, Michael (2007-05-01). The A-Z of Popular Scooters & Microcars: Cruising in Style!. MBI Publishing. p. 138. ISBN 1-84584-088-7.
The enclosed engine did not have a cooling fan which, on occasion, led to overheating problems.
- Hicks, Clifford B., ed. (April 1961). "More power to you! on the new Harley-Davidson Topper H motor scooter". Popular Mechanics. 115 (4): 229. ISSN 0032-4558. Retrieved 2012-09-02.
A 5-hp Model "U" Topper is also available to comply with junior licensing laws in some states.
- Ismon, Alton, ed. (November 1959a). "1960 Harley-Davidsons". American Motorcyclist. Westerville, OH USA: American Motorcyclist Association. 13 (11): 12–14. ISSN 0277-9358. Retrieved 2012-07-25.
- Ismon, Alton, ed. (December 1959b). "Topper Makes Test Run at Death Valley". American Motorcyclist. Westerville, OH USA: American Motorcyclist Association. 13 (12): 35. ISSN 0277-9358. Retrieved 2012-09-02.
- Ismon, Alton, ed. (May 1961). "Topper H Sports Improved Features". American Motorcyclist. Westerville, OH USA: American Motorcyclist Association. 15 (5): 18. ISSN 0277-9358. Retrieved 2012-09-02.
- Ismon, Alton, ed. (November 1962). "'63 Harley-Davidsons". American Motorcyclist. Westerville, OH USA: American Motorcyclist Association. 16 (11): 12–13. ISSN 0277-9358. Retrieved 2012-09-02.
- Wood, Bill, ed. (October 2004). "1960 H-D Topper: Milwaukee goes scootering". Museum Classic. American Motorcyclist (Members' magazine). Pickerington, OH US: American Motorcyclist Association. 58 (10): 67. ISSN 0277-9358. Retrieved 2015-04-19.
- Wright, David K. (1987) . "Chapter Three: Iron". The Harley-Davidson Motor Company: An Official Eighty-Year History (Second ed.). Motorbooks International. pp. 46–97. ISBN 0-87938-245-7.
William H. Davidson told directors that 10,000 were made and sold in the first seven months of 1947.
- "Harley-Davidson Timeline 1960s". Harley-Davidson Timeline. Harley-Davidson. 2015. Archived from the original on 2006-10-29. Retrieved 2015-04-19.
The Harley-Davidson Topper motor scooter is introduced and is the only scooter platform the Motor Company ever produced.
- The Auto Editors of Consumer Guide (2007-09-18). "1963 Harley-Davidson Topper". How Stuff Works. Archived from the original on 2009-12-03. Retrieved 2015-04-19.
Its 165-cc two-stroke single was started with a recoil starter, like a lawn mower, and drove through a variable-ratio automatic transmission called Scootaway Drive.
- "Lambretta Model E". Lambretta Club of Great Britain. Archived from the original on 2010-06-23. Retrieved 2012-12-24.
To start the scooter a pull cord (like that found on chain saws) was mounted in front of the magneto, the ignition on the E could be advanced and retarded for ease of staring (sic) on the pull cord, this ensured the machine did not 'kick back' injuring the person while starting it.