"Bicycles will be removed" - legal?

^Good to know! Oh, another tip : Apparently, a parking warden cannot issue a fixed penalty parking fine on your car if there is no street sign! So if you unscrew the sign, you can't get fined.

I've never removed a sign myself but from time to time I've found a parking bay without any signs and parked for free but I always leave a big note in the window along the lines of 'no parking restrictions, DO NOT TICKET'. This also worked for me on a section of yellow line with a wvm sized gap following a repair to the road surface. Most wardens now photograph the vehicle, the ticket and the parking restrictions sign.