Harley-Davidson Knucklehead Chopper: A two-wheeled icon


Born to be wild, ‘The Motorcycle: Design, Art, Desire’ exhibition will get your motor running, so get up close to a chopper, a platform for artistic and mechanical expression, with extravagant use of chrome, wildly extended springer forks and brilliant paintwork on the tank. Now a piece of American history, it’s one of 100 motorcycles showcasing radical concepts, record breakers and road icons. This world-exclusive exhibition is only in Brisbane’s Gallery of Modern Art (GOMA) until 26 Apr 2021.

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‘The Motorcycle: Design, Art, Desire’, Gallery of Modern Art (GOMA), Brisbane / Photograph: Natasha Harth © QAGOMA

Harley-Davidson Knucklehead Chopper C.1973 (Engine: 1941)

The chopper is a type of customised motorcycle that emerged in California in the late 1950s. It is perhaps the most extreme of all custom motorcycle styles, often using radically modified steering angles and lengthened forks for a stretched-out appearance. They can be built from an original motorcycle which is modified (‘chopped’), or from scratch. Other characteristic features of choppers include: hardtail frames (frames without rear suspension); very tall ‘ape hanger’ or very short ‘drag’ handlebars; lengthened or stretched frames; and larger than stock front wheels. The ‘sissy bar’ — a set of tubes that connect the rear fender with the frame — is also a signature feature of many choppers.

DELVE DEEPER: Browse the LIST OF MOTORCYCLES in the exhibition: From humble origins to cutting-edge prototypes

This Harley-Davidson chopper is built around a 1941 Knucklehead engine, a perennial favourite for chopper builders. At the top of the cylinders knobby covers are held in place by two large nuts — these are the rocker covers, and their knuckly contours gave rise to the nickname, which became popular among chopper builders in the 1960s and 1970s. The rest is the builder’s own imagination, played out in the chrome details, the forks, the high handlebars and pinstripe paint.

‘Where did you get the motorcycle?’
‘It’s not a motorcycle, baby, it’s a Chopper.’
Pulp Fiction 1994

Peter Fonda riding a Captain America chopper / Photograph: Brian Snelson / Image Courtesy: Wikimedia Commons

Custom Motorcycles

It was not until Honda revolutionised industrial production in the 1960s that motorcycles started to be built to exacting technical standards. Prior to that, in Britain, Europe and the United States, new machines might only be a ride away from having a part break or fall off — commonly referred to as a ‘shakedown ride’. Customisation was born from this need to repair and maintain new motorcycles, but went further, to make motorcycles better, faster, louder, brighter and different to factory-produced models.

So-called ‘cut-downs’ and ‘bob-jobs’, aimed at reducing a motorcycle’s weight, were the first customs to emerge in the United States in the 1920s and 1930s. After World War Two, the terminology changed: custom bikes were now ‘choppers’, with exuberant paintwork, indulgent chrome, wildly extended front forks and high, ‘ape-hanger’ handlebars, famously featured in Dennis Hopper’s 1969 film Easy Rider which gave central roles to two Harley-Davidson choppers, thereby enshrining the design in popular culture.

RELATED: Read more about the bikes in ‘THE MOTORCYCLE’ exhibition

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Harley-Davidson Knucklehead Chopper c.1973 (engine: 1941) / Private Collection / Photographs: Andrea Beavis


Country: USA
53 hp

Engine: 1207 cc OHV 45° V-twin
Production: Custom

Interesting facts

  • ‘Knucklehead’ is a word used by enthusiasts to refer to a Harley-Davidson motorcycle engine, named after the distinct shape of the rocker box covering for an overhead valve that resembles two knuckles on a clenched fist.
  • The spark plugs of a knucklehead fire at uneven intervals, contributing to its unique cadence, described as sounding like ‘potato, potato, potato’; ‘pop, pop, pause’; or the ‘snap, crackle, pop’ of the motor running.
  • On 27 January 1973 President Richard Nixon signed the Paris Peace Accords, ending direct US involvement in the Vietnam War. On their return, Vietnam veterans turned to the camaraderie, excitement, danger, speed and escapism of motorcycles and biker clubs. The huge success of the 1969 film Easy Rider instantly popularised the chopper around the world, and drastically increased demand for them. What had been a subculture known to a relatively small group of enthusiasts in a few regions of the US became a global phenomenon.

Music to ride

Tom Petty & The Heartbreakers Fooled Again

Tom Petty & The Heartbreakers ‘Fooled Again (I Don’t Like It)’ featured on their 1976 debut album ‘Tom Petty & The Heartbreakers’

Watch: Motorcycles on Screen

In association with ‘The Motorcycle: Design, Art, Desire’, the Australian Cinémathèque at the Gallery of Modern Art (GOMA) presents the free program ‘Motorcycles on Screen’, which explores the rich history of the vehicle in cinema, from the silent era to today. ‘Motorcycles on Screen’ runs until 25 April 2021.

Easy Rider

This now-classic road movie turned the B-movie youthquake into an international art cinema. Easy Rider 1969 tells the story of Captain America and Billy the Kid as they go looking for America. As they motor along to their inevitably tragic end, our heroes do drugs, have their rights violated, meet some interestingly allegorical groups of folks, and find themselves framed by László Kovács’s gorgeous cinematography.

Production still from Easy Rider 1969 / Director: Dennis Hopper / Image courtesy: Park Circus

Buy: ‘The Motorcycle’ publication

With over 320 pages and 400 colour illustrations, The Motorcycle: Design, Art, Desire showcases 100 superb examples of motorcycle design from the late 19th century to the present day and beyond to the technological innovations of the future. Beautifully illustrated with newly commissioned photography and archival ephemera, this visually arresting survey of the motorcycle’s influence in realms as diverse as film, fashion, sport, advertising, and technology will prove compulsive reading to design lovers and motorcycle fans alike. Available at the QAGOMA Store and online

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