I've always wondered about this, interesting reading.
So in summary,
-in Richmond Park you can definately be done for speeding. (20 mph limit). Very easily done down Broomfield hill where i've hit nearly 40 before. David Millar did'nt get in trouble and he put a video up of him doing over 30 mph average round the park did'nt he? And he's Scottish! I'm surprised Liz2 did'nt send him to the Tower of London. I know the video was removed from youtube or wherever he posted it. Can you be fined from video evidence alone even if the cops were'nt present to witness it first hand? I wonder if the Rozzers would have fined him if they'd caught him or let him off as he's pro.
-Although the law does not strictly say so you could be fined for furious cycling if you cycled at over 30 mph in a 30 mph zone, but there would have to be some evidence of 'furiousness' beyond just the speed itself? Seems vague, but for example speeding past a school at opening and closing times, which in places is a 20mph zone I can see it as reasonable. As for speeding past the same school in the evening with no one around an no traffic, I don't see anything wrong with that.
-As already mentioned I had also wondered about the increase in liklihood of cyclists being fined in London with the spread of 20mph zones (some entire boroughs are proposing a 20 mph limit, not just outside schools). I wonder if this means the law will be reviewed/challenged on this soon.
-Out on the open highway (60mph limit) we do not have any alpine type descents long enough to allow us to get to this speed in this country do we? I've managed 50mph descending in Wales but thats as fast as I've been, and that felt fast enough on a flexy old steel frame from the 80's. But even if you were able to top 60mph I guess out in quiet rural areas it would be hard to prove you were a danger to anyone but yourself so not sure any attempt to fine would be successful. Personally I think you'd deserve a medal!
-But what about Graham Obree and Beastie, he is trying to reach 100mph no? If you get caught doing 100mph in a car you lose you licence automatically don't you? Irrespective of danger to others or anyone in the vicinity, cycling at 100mph could'nt be described as anything other than furious could it? What would PC plod make of that?