QUOTE (Logician @ Mon, 7 Oct 2013 - 16:44)

Sorry, the time recorded for the offence being a few minutes wrong does not provide any reasonable doubt about the speed measured, as CO explains above. You did not even dispute the speed when you were talking to the officer, you might for instance asked him if he was sure it was your speed and not that of the taxi. It is too late now, you would be foolish to go to court on this, you would almost certainly lose and the fine and points would be higher and the costs crippling.
The fixed penalty is the same for 47 as for 35, so unless you believe you were doing 30 or less you have not been disadvantaged, actually.
Further:
Once the matter goes to court, the FPN is no longer relevant, and any minor errors on the summons may be corrected, so it goes something like this:
CPS: Officer, please tell the court what happened.
Officer: I saw a motorbike behind the taxi, formed an opinion that it was exceeding the speed limit, aligned the cross hairs of the device on a vertical surface and pulled the trigger. The measured speed was 47mph. I caused the motorbike to stop, showed Mr RedE the reading and cautioned him for the offence of speeding. He made no comment.
Defence solicitor asks police officer what time offense took place, he says 22:56.
Defence: "How can you be sure?"
Officer: "I have it my notebook and it is in the log from the SL700".
Defence: "When did you last set the clock on the SL700"
Officer: "Huh?"
Defence: Mr RedE used a smartphone to photograph the reading on the device, this has an internal clock reset automatically, so there is conclusive proof that this alleged offence occurred not at 22.56 as you claim but at least 5 minutes earlier.
Officer: Well, that may be the case.
Magistrate: Where exactly are you going with this, Mr Defence Solicitor?
Defence: Errr.....dunno really.
I was hoping that it would proceed as follows:
Magistrate: Where exactly are you going with this, Mr Defence Solicitor?
Defence Solicitor: If your Worship would please bear me with, I am about to uncover a monumental flaw in the procedures employed by the police.
Magistrate: Proceed Mr Solicitor, but do make it brief?
Defence Solicitor: Officer, do you know what time it is and don't look at the wall clock?
Officer: Its um, eh about 12:45pm.
Defence Solicitor: Yes it is about 12:45. Its also about 12:44, about 12:43 and about 12:41. It is in fact 12:41 and 25 seconds.
Officer: Well you told me not to look at the clock
Defence Solicitor: But I didn't say you should not look at your watch or even your mobile telephone. So what is the time on your wrist watch?
Officer: I don't wear one
Defence Solicitor: I see, so could you tell the court how you determined my client was speeding at 22:56?
Officer: I looked at the time on the SL700
Defence Solicitor: But the clock on the SL700 is evidently wrong. It is fast by some 13 seconds, or should I say at least three hundred and 13 seconds.
Magistrate: Mr Defence Solicitor, would you care to tell us what the relevance of all of this clock watching is?
Defence Solicitor: My client was not in fact travelling at an excess speed of 47 miles per hour when as the officer claims at the location specified. He was in fact some 4000 meters away and I would argue completely out of sight of the officer and certainly out of the range of his device. The Crown cannot rely on the evidence of the officer if it is so patently incorrect. What actually happened that evening is that the Officer saw my client return to the lane in front of the Officer and missed the opportunity to correctly measure his speed.
QUOTE (Logician @ Mon, 7 Oct 2013 - 17:19)

QUOTE (RedE @ Mon, 7 Oct 2013 - 16:55)

Although, not mentioned in the post, so far, I did in fact question, and question vigorously, whether the reading was correct.
I never admitted nor denied that I was speeding?
Here is about how the initial interaction with the traffic officer went:
Officer: "Do you know why you were stopped?"
Me: "No idea whatsoever............[Pause] Could it be related to a speed limit?"
Officer: "You were travelling at 47 mph [he shows me device] in a 30 mph zone"
Me: "Is that possible?"
and later:
Me: "Are you sure you were pointing that thing at my vehicle? I was travelling in a cluster of 3 vehicles and my vehicle is only about 80 cm wide. Are you sure it was not the van behind me or the taxi to my right?"
OK, so you did question the speed measured at the time, and suggested he pointed it at a different vehicle. He presumably stuck to his guns and insisted he measured the speed of your bike. It is unlikely that he would say any different if questioned in court.
Do you believe you were travelling at or below the speed limit?
Yes, he said "I am satisfied that yours was the lead vehicle"
Also, though not at this part of the conversation " I am satisfied that you were not driving dangerously"