So on my ride into work today, I passed a policeman who was running a radar speed trap. He was pointing the handheld radar gun at me (there were no cars behind me, so he was definitely pointing it at me). Firstly, it was wishful thinking that I'd be anywhere near the 30mph speed limit - but I was surprised I'd present enough of a radar reflection for his speed gun to work.
Have the police ever pulled a cyclist over in a radar trap? Have cyclists ever set off a GATSO?
In news:[email hidden], Dylan Smith <[email hidden]> tweaked the Babbage-Engine to tell us:
Quoted message said:
Have the police ever pulled a cyclist over in a radar trap? Have cyclists ever set off a GATSO?
Tried very hard to set off the GATSO at the bottom of the hill where the A261 comes into Hythe the other week, but no joy. Though one of those flashing "You are exceeding the 30 mph speed limit" jobs went off at me on Saturday near Tytherington.
Firstly, it was wishful thinking that I'd be anywhere near the 30mph speed limit - but I was surprised I'd present enough of a radar reflection for his speed gun to work.
Have the police ever pulled a cyclist over in a radar trap? Have cyclists ever set off a GATSO?
I wonder how much surface area these guns need to get a reflection - say you're going at 20mph, the top of your tyres are moving forwards at 40mph. Another argument against big knobbly bits on your tyres? ;o)
Have the police ever pulled a cyclist over in a radar trap?
If they did they cannot charge you with speeding, but could try cycling recklessly if they really thought it would be upheld in court. I guess that it would need to in a place crowded with pedestrians or around a blind bend or truly phenomenal speeding for a bike. I suppose he was just interested to see what reading he got. TerryJ
So on my ride into work today, I passed a policeman who was running a radar speed trap. He was pointing the handheld radar gun at me (there were no cars behind me, so he was definitely pointing it at me). Firstly, it was wishful thinking that I'd be anywhere near the 30mph speed limit - but I was surprised I'd present enough of a radar reflection for his speed gun to work.
A policeman cheerily informed me of my speed (which concurred with the readout on my speedo) after pointing a radar gun at me, so I'm convinced that it is possible to get a reading from a cyclist.
Firstly, it was wishful thinking that I'd be anywhere near the 30mph speed limit - but I was surprised I'd present enough of a radar reflection for his speed gun to work.
Have the police ever pulled a cyclist over in a radar trap? Have cyclists ever set off a GATSO?
I wonder how much surface area these guns need to get a reflection -
No idea.
Quoted message said:
say you're going at 20mph, the top of your tyres are moving forwards at 40mph. Another argument against big knobbly bits on your tyres? ;o)
Yes, but they don't detect rotation speed; they detect the movement of an object relative to the position of the gun operator, surely?
In news:[email hidden], Anthony Jones <[email hidden]> tweaked the Babbage-Engine to tell us:
Quoted message said:
Dylan Smith said:
So on my ride into work today, I passed a policeman who was running a radar speed trap. He was pointing the handheld radar gun at me (there were no cars behind me, so he was definitely pointing it at me). Firstly, it was wishful thinking that I'd be anywhere near the 30mph speed limit - but I was surprised I'd present enough of a radar reflection for his speed gun to work.
A policeman cheerily informed me of my speed (which concurred with the readout on my speedo) after pointing a radar gun at me, so I'm convinced that it is possible to get a reading from a cyclist.
Have the police ever pulled a cyclist over in a radar trap? Have cyclists ever set off a GATSO?
I believe it happens in Richmond Park which is one of the few places the cyclist can commit a speeding offence. They are also widely used in Marin County in California where Park Rangers enforce the 15mph cycle speed limit on the trails with radar guns. Its quite difficult to keep your speed that low going downhill.
-- Tony
"The most savage controversies are those about matters as to which there is no good evidence either way." - Bertrand Russell
In news:[email hidden], Anthony Jones <[email hidden]> tweaked the Babbage-Engine to tell us:
Quoted message said:
Dylan Smith said:
So on my ride into work today, I passed a policeman who was running a radar speed trap. He was pointing the handheld radar gun at me (there were no cars behind me, so he was definitely pointing it at me). Firstly, it was wishful thinking that I'd be anywhere near the 30mph speed limit - but I was surprised I'd present enough of a radar reflection for his speed gun to work.
A policeman cheerily informed me of my speed (which concurred with the readout on my speedo) after pointing a radar gun at me, so I'm convinced that it is possible to get a reading from a cyclist.
o D++ly M++l, and o factual inaccuracies (207 mph on rollers is /not/ cycling)
The cyclist says some odd things too.
For absolute maximum power on an upright you can 'stand' on the pedals. Can you *really* get that much power into a recumbant?
And his comment about the energy not being transmitted through 90 degrees seems somewhat off the mark. Every rec I've seen appears to need a much more complex transmision system than an upright.
No doubt rec riders will put me straight if I've misinterpretted anything.
In article <[email hidden]>, Simon D [email hidden] says...
Quoted message said:
[email hidden] formulated on Wednesday :
Quoted message said:
Dylan Smith said:
Firstly, it was wishful thinking that I'd be anywhere near the 30mph speed limit - but I was surprised I'd present enough of a radar reflection for his speed gun to work.
Have the police ever pulled a cyclist over in a radar trap? Have cyclists ever set off a GATSO?
I wonder how much surface area these guns need to get a reflection -
No idea.
Quoted message said:
say you're going at 20mph, the top of your tyres are moving forwards at 40mph. Another argument against big knobbly bits on your tyres? ;o)
Yes, but they don't detect rotation speed; they detect the movement of an object relative to the position of the gun operator, surely?
The forks are moving towards the gun operator. The top of the tyre is moving forward relative to the forks. The top of the tyre is moving towards the gun operator faster than the forks.
Or
The tyre contact patch is stationary. The axle is moving at speed V. In order for the whole wheel to be moving at speed V the top of the tyre must be moving at speed 2V so the average speed of the wheel is the same as the average speed of the axle.
"Tony Raven" <[email hidden]> wrote in message news:[email hidden]...
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Dylan Smith wrote on 11/04/2007 10:33 +0100:
Quoted message said:
Have the police ever pulled a cyclist over in a radar trap? Have cyclists ever set off a GATSO?
I believe it happens in Richmond Park which is one of the few places the cyclist can commit a speeding offence. They are also widely used in Marin County in California where Park Rangers enforce the 15mph cycle speed limit on the trails with radar guns. Its quite difficult to keep your speed that low going downhill.
It wasn't me hacking down a RP hill last night at 35mph, overtaking three cars and catching up a park ranger. Honest, guv.
For absolute maximum power on an upright you can 'stand' on the pedals. Can you *really* get that much power into a recumbant?
More, probably, seeing as you can brace against the seat back and that'll surely give you more to push against than your own weight.
Quoted message said:
And his comment about the energy not being transmitted through 90 degrees seems somewhat off the mark. Every rec I've seen appears to need a much more complex transmision system than an upright.
Recumbents often have longer chains than average diamond framed bikes, but I can't see why that should make a massive difference. 90 degrees, though - er, so what? It's a rotary system anyway.
Firstly, it was wishful thinking that I'd be anywhere near the 30mph speed limit - but I was surprised I'd present enough of a radar reflection for his speed gun to work.
Quoted message said:
Have the police ever pulled a cyclist over in a radar trap? Have cyclists ever set off a GATSO?
I wonder how much surface area these guns need to get a reflection - say you're going at 20mph, the top of your tyres are moving forwards at 40mph. Another argument against big knobbly bits on your tyres? ;o)
Quoted message said:
From memory, I would have to look it up to be precise, and it would
depend on the type of gun being used, but the LTI 2020 has a beam of about 3500meters and a 1m divergence at 1000m. At normal distances this equates to about 4.5 to 8.0 cm of target area.
For absolute maximum power on an upright you can 'stand' on the pedals. Can you *really* get that much power into a recumbant?
More, probably, seeing as you can brace against the seat back and that'll surely give you more to push against than your own weight.
Yes, that makes sense.
Quoted message said:
Quoted message said:
And his comment about the energy not being transmitted through 90 degrees seems somewhat off the mark. Every rec I've seen appears to need a much more complex transmision system than an upright.
Recumbents often have longer chains than average diamond framed bikes, but I can't see why that should make a massive difference. 90 degrees, though - er, so what? It's a rotary system anyway.
That's what I thought!
I must say, rec's look great fun and very comfortable but I'd really worry about my visibility if I was using one. Probably without good reason I'll admit.
"Dylan Smith" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
So on my ride into work today, I passed a policeman who was running a radar speed trap. He was pointing the handheld radar gun at me (there were no cars behind me, so he was definitely pointing it at me). Firstly, it was wishful thinking that I'd be anywhere near the 30mph speed limit - but I was surprised I'd present enough of a radar reflection for his speed gun to work.
Have the police ever pulled a cyclist over in a radar trap? Have cyclists ever set off a GATSO?
They do not pull you over, they identify you from your number plate and send you a NIP, might be a bit difficult to find a number plate on a bicycle though!
"TerryJ" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
Quoted message said:
Quoted message said:
Have the police ever pulled a cyclist over in a radar trap?
If they did they cannot charge you with speeding, but could try cycling recklessly if they really thought it would be upheld in court. I guess that it would need to in a place crowded with pedestrians or around a blind bend or truly phenomenal speeding for a bike. I suppose he was just interested to see what reading he got.
Which would be inaccurate, as those things have been well documented in showing stationary object travelling at speed!
"Simon D" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
[email hidden] formulated on Wednesday :
Quoted message said:
Dylan Smith said:
Firstly, it was wishful thinking that I'd be anywhere near the 30mph speed limit - but I was surprised I'd present enough of a radar reflection for his speed gun to work.
Have the police ever pulled a cyclist over in a radar trap? Have cyclists ever set off a GATSO?
I wonder how much surface area these guns need to get a reflection -
No idea.
Quoted message said:
say you're going at 20mph, the top of your tyres are moving forwards at 40mph. Another argument against big knobbly bits on your tyres? ;o)
Yes, but they don't detect rotation speed; they detect the movement of an object relative to the position of the gun operator, surely?
But the top of the tyre would be moving, at a speed twice that of the cycle!
Firstly, it was wishful thinking that I'd be anywhere near the 30mph speed limit - but I was surprised I'd present enough of a radar reflection for his speed gun to work. Have the police ever pulled a cyclist over in a radar trap? Have cyclists ever set off a GATSO?
I wonder how much surface area these guns need to get a reflection -
No idea.
Quoted message said:
say you're going at 20mph, the top of your tyres are moving forwards at 40mph. Another argument against big knobbly bits on your tyres? ;o)
Yes, but they don't detect rotation speed; they detect the movement of an object relative to the position of the gun operator, surely?
There are different devices on the market. Some work by detecting the doppler shift in the returned signal, some work my measuring the differential position and hence speed of the object they're pointed at. There have been occasions where the police have tried to do people for twice the speed they were actually doing because of the radar return from the top of an advancing wheel being stronger than that from the main bike body and rider.
"Dave Larrington" <[email hidden]> wrote in message news:[email hidden]...
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Tried very hard to set off the GATSO at the bottom of the hill where the A261 comes into Hythe the other week, but no joy. Though one of those flashing "You are exceeding the 30 mph speed limit" jobs went off at me on Saturday near Tytherington.
We've got some of them round here, will have to try it one morning when there's no cars or buses about (that would slow me down!)
The ones which display your speed seem to work on most things the sensor is pointed at - I walked towards one at an exhibition and it said I was doing 4 mph. -- peter
