Request for help IDing Young Adult (?) Motorcycle SF

Growing up in suburban Northern New Jersey I would checkout SF books from the little local library.  Here's one I periodically think about, the name or author of which I cannot recall.  Maybe one of you out in internet land will recognize it?  I can be a little oblivious, so maybe this thing is very famous and dozens of you will know it.  The book was a hardcover, and I must have read it in the early 1980s.  I think the cover illustration was moody, a yellowish tan, with people standing still, looking sadly or grimly out at the viewer.

THE PLOT: It's the future in Great Britain.  A totalitarian government is in charge; they have flying robots which can read your emotions and detect if you are angry or upset.  The main character is a teenage boy, and he escapes and joins some kind of motorcycle gang of rebellious kids in the countryside.  The main character has an advantage over the other kids because he has a modern Japanese motor bike; I think most of them have cobbled together British bikes.  (I seem to recall one character saying something derisive like "Don't ride that Jap crap!  Ride British!")  Even though I got this book out of the YA section, there was sex in it, and in the end of the novel is a scene in which the main character and his girlfriend have sex when a flying robot comes by, because the robots have trouble distinguishing between sexual passion and rebellious anti-government emotions.

Any clues would be appreciated!