It sounds as if 20 mph limits are going to be introduced quite widely in areas of London. http://www.standard.co.uk/news/transport/london-could-see-20mph-speed-limit-on-nearly-all-residential-streets-by-2020-8648655.html.
Is this really a benefit to cyclists? I often go faster than 20mph on my bike so will have to use a bike computer and be careful not to speed. I suppose if it's restricted to residential streets I can live with it, but I hope it doesn't get applied too widely.
I live near Regent's Park where road cyclists often go around the Outer Circle at speeds that must be close to 30mph. This is a residential area (albeit a very expensive one). I hope a reduced limit won't be introduced there - it would seem very unfair to people who want to get some exercise.
Personally as a cylist I'm quite happy with the current speed limits.