I got a cheerful ‘not quite’ from a speedgun holding bobby once as i was doing approx 28.5mph once!
Yep, a group of 3 of us got shouted at once by a policeman with a speedgun – he said “34, good work lads!”
You can’t be done for speeding on a bike as there’s no legal requirement to have a speedo (in fact the law was written way before computers etc became commonplace) so there’s no way that the cyclist is expected to know their speed.
I was descending Caerphily Hill once years ago, pulled out round a slow moving car and then realised why he was slow moving – there was a police car right in front of him. By then I was committed to the overtake, got 54mph down the hill with the police car behind me. They never said a word, it was quite disappointing really. 😐