Of course I don't actually overtake, however since not required to have a speedometer not sure what the law would do, think called peddling furiously, but since free wheeling not sure how that would work.
I can see where past schools etc there should be a 20 MPH speed limit, but what has happened in North Wales is simply daft, no reason for the 20 MPH limit, and car drivers have a problem as the speedo does not need to be accurate at that speed, and the cruse controls etc, will not work at 20 MPH and to travel on near empty roads for miles in a straight line at 20 MPH is very boring and one ends up not paying attention.
Also there are reports the experiment has been abandoned, so some obey the limit other don't so it is a bit of a free for all.
The rules were to have less than 30 MPH on a permanent basic you need traffic carming, and Flintshire not wanting to erect the carming measures erected signs with 20 in red and circle in black as advisory signs, over the years these have faded, and since they are unofficial there is no end of speed limit, so no one has a clue which you need to obey.