Many late 1970s cars are seen in the background. Particularly during the "Goldhawk Road" and "Brighton riot" scenes. Similarly, all the street furniture, road markings and road signs are from the same era, and signs can be seen in (Brighton) shop windows advertising credit cards.
A Pepsi logo that was not introduced until 1973 appears on the Brighton ice cream shop window behind Steph as Jimmy is carried off to the paddy wagon, as well as the mod hangout Alfredo's Snack Bar in a subsequent scene.
in one scene Jimmy is in his bedroom and a train is seen moving quickly passed his window. The train is an 'Inter-City 125' which was not introduced on British Rail until the 1970s - the film is set in the 1960s.
This movie is supposed to be set in 1964, yet at the party the Mods dance to
The Who's "My Generation"...a song not released until late 1965. Also Jimmy watches The Who on "Ready Steady Go" on TV performing "Anyway, Anyhow, Anywhere", also not released until 1965.
In one scene Jimmy and his friends drive their scooters with a 'Goldhawk Building Society' sign prominently visible in the background, on the side of a railway bridge. This organization did not come into existence under that name until the early 1970s and had folded by 1981.
The shadow of the helicopter that filmed the final scenes on the white cliffs at Beachy Head is visible. Most people call these the white cliffs of Dover, but they aren't. The cliffs at Beachy Head are higher than the white cliffs of Dover.
When Jimmy boards the train to Brighton, the locomotive shown is a Class 50, number 50 008. This number was applied in 1974, and the class was used exclusively on Paddington services, at the time of filming.
When Jimmy enters the scrap yard to see Peter Fenton, an 'NF' (National Front, a British white supremacist political party) graffiti is seen scrawled on the gates. The National Front was not officially formed until 1966, and its 'NF' symbol was not commonly seen in graffiti until the mid 1970's.
To get down to Brighton, Jimmy says that they left London while it was still dark, and in the scene when he's getting dressed to leave, it's pitch black outside his windows while the radio says the time is 6:01 AM. The beach fight/riots take place during the Whitsun Bank Holiday, which in 1964 took place on May 18. Sunrise in London on May 18 is at 5:05 AM so it would have been fully light by 6:01 AM.
In the scene where Jimmy and Steph are riding on Jimmy's scooter, they appear to be travelling at normal speed, but Jimmy keeps the scooter in first gear. This is because the scene was shot with the actors and the scooter on a trailer being towed by the camera car.
When Jimmy is giving Steph a ride home, his scooter comes to a halt. Then the scooter accelerates away while Jimmy's left hand is still squeezing the clutch lever. He releases the clutch lever only after the scooter has picked up speed, indicating that it is on a trailer being towed by a camera car.
The GS appears to have gone over the cliff twice. The initial shot of the scooter leaving the cliff show the scooter looking odd. This is due to damage received during the first take. The spare tire (behind the back-rest) is missing and the right-hand side cover can be seen coming free. The long, slow close-up shots of it falling are from the first take. Immediately after impact, it cuts to the second take's impact with the scooter in a different orientation and position (presumably as it was more spectacular). It is possible they missed the initial shot on the first take and had to re-do it using a long shot to disguise the damage to the scooter.