Caught Speeding, how accurate is Scooby Speedo?
24 March 2009, 07:29 PM
#1
Caught Speeding, how accurate is Scooby Speedo?
Just received a NIP for speeding at 35MPH in a 30. 
Thing is, either my speedo or their fcucking camera must be wrong - saw the scamera van as soon as I exited the roundabout, it was parked on the grass verge next to the bus stop in the second picture. I was very careful to keep the speedo dead on the 30.
Anyone know how regularly these things have to be calibrated by law?
Anyone else had similar problems with an inaccurate speedo reading, I thought they were meant to read too high as opposed to too low..
Really pissed off, my first points since 1998...
Thing is, either my speedo or their fcucking camera must be wrong - saw the scamera van as soon as I exited the roundabout, it was parked on the grass verge next to the bus stop in the second picture. I was very careful to keep the speedo dead on the 30.
Anyone know how regularly these things have to be calibrated by law?
Anyone else had similar problems with an inaccurate speedo reading, I thought they were meant to read too high as opposed to too low..
Really pissed off, my first points since 1998...
24 March 2009, 07:37 PM
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i know how you feel mate but i do tink the scooby speedo is out as onmy sat nav when i'm driving along at 70mph on the speedo the sat nav says i'm driving 63-64mph and i know my sat nav isin't broken as on my seat ibiza 30mph on the speedo was 30mph on the sat nav. if you don't mind me asking what model do you have?
24 March 2009, 07:47 PM
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24 March 2009, 07:47 PM
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Most speedo's over read, never had one which under reads, not than i am aware of. If ther speedo over reads then the manufacturer of the speedo/car are safe from procecution for speeding which is one reason they err on the side of caution.
Can you get it checked against something accurate, if it does under read then surely you will have a good case against IM. Only if it does of course.
Can you get it checked against something accurate, if it does under read then surely you will have a good case against IM. Only if it does of course.
24 March 2009, 07:49 PM
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'fraid to say, but mine over-shows as well. I've got a micro-roadpilot and the GPS display indicates 65 while the speedo shows 70. Its been the same with all the sccobs I've had.
If the GPS shows 30 the speedo displays 34 - 06 STi Spec D
Gareth
If the GPS shows 30 the speedo displays 34 - 06 STi Spec D
Gareth
24 March 2009, 07:52 PM
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i know how you feel mate but i do tink the scooby speedo is out as onmy sat nav when i'm driving along at 70mph on the speedo the sat nav says i'm driving 63-64mph and i know my sat nav isin't broken as on my seat ibiza 30mph on the speedo was 30mph on the sat nav. if you don't mind me asking what model do you have?
BTW, mine overreads too. (speedo is faster than real speed)
24 March 2009, 07:59 PM
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have a look around on this site for information on calibration and general advice
just to add, my speedo reads over by around 10-15% ie speedo says 34mph, GPS says 30mph. thats a 1998 uk turbo 2000
just to add, my speedo reads over by around 10-15% ie speedo says 34mph, GPS says 30mph. thats a 1998 uk turbo 2000
24 March 2009, 08:02 PM
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24 March 2009, 08:07 PM
#15
Originally Posted by ACPO
Vehicle construction and use regulations require a vehicle speedometer accuracy to be in the range of -0->+10%. The implications are that it must never under-read - for obvious reasons - but may over-read. As the cost of manufacturing a speedometer with -0% error would be very costly they all over-read by a few percent without exception. Even if speed is measured correctly the display may not be accurate, so a speedometer error is allowed. Because of this, the Association of Chief Police Officers (ACPO) have an official formula for calculating a speeding offence. It allows a leeway of 10% plus 2mph. In reality, most speed traps are triggered at higher speeds than this because if they were set bang-on those guidelines, the sheer amount of paperwork generated would overrun the police speeding departments.
), especially if you can prove your speedo was defective and you didn't know. It's not like you were haring past the thing with no regard whatsoever is it? You were clearly conscious of your speed and keep to what your speedo told you is the limit! Good luck 
24 March 2009, 08:12 PM
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you are quite correct. look at this useful site for a comparison of wheel sizes and its effect on indicated speed
If you've changed the rim size bigger then you need to reduce the tyre profile to make sure the speedo shows accurate.
24 March 2009, 08:44 PM
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I thought that if you are caught just over the limit you get the chance to pay a slightly larger fine and attend a speeding course ? then you don't have to take the points.
24 March 2009, 08:44 PM
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As covered by PSIGEEK, I would have said go to their web site and look up to see if they operate the 10% + 2, if so that suggests that you should not have received the NIP, then I suggest you check your speedo. I have a classic and that reads 35mph whilst the Sat Nav + SECS read about 30mph, Good luck and start sending a letter or two.
24 March 2009, 09:02 PM
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Try and get it checked on a Rolling Road ?
IF you could prove you didn't know your speedo was out of calibration, you MAY get a positive result.
Mine 74 mph speedo = 70 actual
Or 101 mph speedo = 100 mph, on my OZ's with R888's.
Good luck,
dunx
IF you could prove you didn't know your speedo was out of calibration, you MAY get a positive result.
Mine 74 mph speedo = 70 actual
Or 101 mph speedo = 100 mph, on my OZ's with R888's.
Good luck,
dunx
24 March 2009, 09:05 PM
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It must have been a slow day for them, you're just unlucky they needed to fudge...i mean meet their targets that day. 35 in a DC 30 is uber harsh.
24 March 2009, 09:12 PM
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unlucky mine reads about 4 miles per hour over the sat nv speed so speedo says 30 sat nav says 26 at speedo 70 sat nav says 66/67 on a private track speedo read 145 sat nav showed 140
24 March 2009, 09:55 PM
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24 March 2009, 10:02 PM
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Fight it,
They tried doing me for 65 in a 50 when in fact I was doing 45 as idicated on my GPS, I opted to take the case to court, after 4 adjournments they dropped the case and appologised,
I then asked for £210 comp for wasting my time and after nearly a year they paid up!!!
They tried doing me for 65 in a 50 when in fact I was doing 45 as idicated on my GPS, I opted to take the case to court, after 4 adjournments they dropped the case and appologised,
I then asked for £210 comp for wasting my time and after nearly a year they paid up!!!
24 March 2009, 10:27 PM
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If you are 100% sure your speedo said 30mph, and as you said your tyres are standard size then I would fight it. These things CAN make errors and the people using them can make mistakes and have been shown in the past to not always adhere to the strict usage guidlines but most people will just cough up and take it on the chin. As I said IF you are innocent of the charges then fight it - take advice from that pepipoo site - ask to see calibration docks for that day etc.
Most likely if they see you standing your ground they will back down as it's usually not worth their while to pursue it if it's close to the threshold (don't hold me to that if it all goes wrong though! lol).
good luck.
Most likely if they see you standing your ground they will back down as it's usually not worth their while to pursue it if it's close to the threshold (don't hold me to that if it all goes wrong though! lol).
good luck.
24 March 2009, 11:21 PM
#26
100% sure they have to be calibrated by law every day, My speedo use to read 66 tomtom 70 then had new or recon box now speedo reads 70 tomtom 72 flat out speedo reads 136 tomtom 149 on track , tomtom does not no of the track but you can still use for speed runs
, tomtom does not no of the track but you can still use for speed runs
24 March 2009, 11:32 PM
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I have 18s on a bug and it over reads by 5mph.
I have been through loads of those speed reading things that show you your speed as you go past and they are always 5mph out....my speedo reads 35mph and they machines say 30mph. 65mph speedo...60 smiley face.....etc
I have been through loads of those speed reading things that show you your speed as you go past and they are always 5mph out....my speedo reads 35mph and they machines say 30mph. 65mph speedo...60 smiley face.....etc
25 March 2009, 12:30 AM
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If your speedo is under reading, that is an offence in itself.
You can work out from the time and distance reading on the photo the time/distance between photos and then your speed in metres per second - you can see then if the indicated speed reading is correct.
In the photo's above, the first shot at 140.3m was at 13:37:53 The second was at 107m at 13:37:56
You had travelled 33.3 metres in 3 seconds which is 11.1metres/second, which is 25mph. You would have needed to travel 15.64 metres per second or 46.9 metres in the 3 second gap from the time of the first photo. In other words, the second reading, if you were doing 35mph would be at 93.4m not 107m. Check my sums, but I think that it's right.
There was a lot in the news last year about the LTI20-20 device as it was found to be not 100% reliable. You need to do some research about it. The devices are calibrated once a year against a measured distance. It's supposed to be within engineering tolerances (mm's), but is carried out by "trained" policeman so it's anybody's guess if they do it properly.
If you go to court, everything is stacked up against you, but it's worth a try if you know you were not speeding, and the calculations above show that you were not.
I went last year with my girlfriend who had allegedly been doing 99.6mph on the motorway in a diesel Skoda. She insists she was doing nowhere near that, as she was turning off onto a slip road and she doesn't drive fast anyway. The magistrate listened to the defence, the time/diatance calculations etc and was very sympathetic, but as all the police paperwork was in order, she was foung guilty - 5 points , £200 fine and £200 costs. She was clocked at nearly 500 metres by a hand held speedgun. We had no photo evidence unfortunately.
Good luck.
You can work out from the time and distance reading on the photo the time/distance between photos and then your speed in metres per second - you can see then if the indicated speed reading is correct.
In the photo's above, the first shot at 140.3m was at 13:37:53 The second was at 107m at 13:37:56
You had travelled 33.3 metres in 3 seconds which is 11.1metres/second, which is 25mph. You would have needed to travel 15.64 metres per second or 46.9 metres in the 3 second gap from the time of the first photo. In other words, the second reading, if you were doing 35mph would be at 93.4m not 107m. Check my sums, but I think that it's right.
There was a lot in the news last year about the LTI20-20 device as it was found to be not 100% reliable. You need to do some research about it. The devices are calibrated once a year against a measured distance. It's supposed to be within engineering tolerances (mm's), but is carried out by "trained" policeman so it's anybody's guess if they do it properly.
If you go to court, everything is stacked up against you, but it's worth a try if you know you were not speeding, and the calculations above show that you were not.
I went last year with my girlfriend who had allegedly been doing 99.6mph on the motorway in a diesel Skoda. She insists she was doing nowhere near that, as she was turning off onto a slip road and she doesn't drive fast anyway. The magistrate listened to the defence, the time/diatance calculations etc and was very sympathetic, but as all the police paperwork was in order, she was foung guilty - 5 points , £200 fine and £200 costs. She was clocked at nearly 500 metres by a hand held speedgun. We had no photo evidence unfortunately.
Good luck.
25 March 2009, 12:59 AM
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Whilst goes against the grain... I suggest you vjust take it .. it is not as if your insurance will be really (if at all) affected and you're not fighting a potential ban.
Plus I am not sure what it is like up there, but in some parts of the country, with being so close to 30 +10% ie 33 mph .. you might be even be offered a road safety course (at the £60 fine rate) with no points ... you wont if you challenge it
Plus I am not sure what it is like up there, but in some parts of the country, with being so close to 30 +10% ie 33 mph .. you might be even be offered a road safety course (at the £60 fine rate) with no points ... you wont if you challenge it
