BSA B25 - If the picture on the right is of the concert promoter zipping around like i've seen in the film. Likely a '68 or '69. I have a '72 and they didn't change much. Yellow and bare aluminum gas tank. Some leftovers in 1973 were sold as Triumphs too.
I'm thinking it was a BSA 441 Victor Special. I don't recall any other BSAs with that distintive yellow paint/aluminum tank.
1970 Yamaha DT125. The next year's models usually started debuting in July or August.
This is actually a 1969 DT1-B 250cc Enduro model.
1966 Triumph T120 Bonneville. Link to "www.vintagebike.co.uk").jpg
BSA? It is a Japanese bike from the late 1960s. From the badge it doesn't look like Suzuki or Yamaha - might be one of the more obscure makes. I think it is a Bridgestone like this one. http://www.motorbike-search-engine.co.uk/classic_bikes/bridgestone-350-gto.jpg http://www.motorbike-search-engine.co.uk/classic_bikes/bridgestone-classic-motorcycles.php The rubber pad on the side of the tank is a different shape to the link
That's a Yamaha guys, YL 1 Twinjet.