The Wild One

Moto différente de celle utilisée par Marlon Brando (Cette dernière possède des sacoches)

La moto au premier plan BSA single - either 350cc B31 or 500cc B34 - with plunger rear end - date about 1949-52.

Not a BSA that I recognise. Wrong timing chest for a B series. Looks like an over head cam engine. A Norton perhaps?

BSA Golden Flash about 1950.

L'arrivée en ville de Chino (Lee Marvin) sur sa Harley

Chopper Harley sur base Knucklehead

Most likely an MSS 500cc from the early 1950s.

This appears to be an Indian Scout rather than a Harley WL. The most obvious feature is the "leafer" front forks something Harley never used. The cylinder heads also like look they belong on a late 1920s 101 Scout.

La première moto (en arrière plan) On the right, a Triumph. Can't be certain of the model but it a sprung hub rear end which would make it about 1949-52.

La moto de gauche Photo publicitaire. Marlon Brando pendant tout le film reste fidèle à sa Triumph That is a 500cc twin - 1950 or 1951 with those rear shocks.

The famous publicity photo features Wally Albright's Matchless (much 'Wild One' trivia on the imdb). As nzcarnerd indicates, the 'jampot' rear dampers almost certainly confirm the machine to be a c.1950 customised G9 498cc twin - with alloy guards, ugly siamesed exhaust and upswept silencer. Personal trivia: walking across London Bridge to school around 1959, on Thursday mornings for a number of weeks, a cloth capped rider wearing goggles used to quite noisily let rip on his then recent G9 with AMC megaphone silencers. 'Bloody madbrain' my father would say, somewhat to the amusement of my brother and me. Often wonder if the rider made it through to middle age, at least.