Criminals on TV



NM <[email protected]> writes:

> Tony Raven wrote:
>> Steve Firth wrote:
>>>
>>>> The cyclist could have been travelling at 10mph or less. This is as
>>>> unlikely, as even most trundlies potter about at more than that.
>>>
>>> Most cyclists grossly over estimate their speed, few have speedometers
>>> and none of thsoe are calibrated.

>>
>> I have one and it is calibrated pretty accurately. Few cyclists are
>> travel as slow as 10mph and I am usually between 15-20mph dropping
>> to maybe 8 or 9 on steeper hills. Next?
>>

>
> How did you get it calibrated?


You do it yourself. Put a dab of mark on the tyre, ride a few metres,
measure the gap between the resulting marks and set the computer
accordingly. Very accurate. Car speedos are generally pretty
inaccurate in comparison - most overread by a few percent.
 
Tony Raven wrote:
> ®i©ardo wrote:
>>
>> When I walk the lanes in the dark to my local I always wear a
>> fluorescent waistcoat and I walk facing the oncoming traffic, although
>> that isn't too relevant given the width of some of the roads. I don't
>> see what the problem is, unless cycling is such a "fashion statement"
>> that you don't want to be shown up, or show up.
>>

>
> I presume you paint your car fluorescent orange too. If not why not, it
> can't just be a fashion thing surely?
>
> Tony


No, my car is metallic bronze and it has lights on it, which I use in
appropriate weather conditions or to meet the requirements of the time
of day/night.

--
Moving things in still pictures!
 
Tony Raven wrote:
> Mortimer wrote:
>
>>
>> I'm surprised we don't have a rule in the UK making lights a
>> compulsory part of a bike.

>
> The law has far more important things to do like mandating a bicycle
> bell at the point of sale ;-)
>
> Tony


Even that could be useful if people learned how to use it.

;-)

--
Moving things in still pictures!
 
NM wrote:
> marc wrote:
>> Brimstone wrote:
>>> Pyromancer wrote:
>>>> Upon the miasma of midnight, a darkling spirit identified as Tony
>>>> Raven <[email protected]> gently breathed:
>>>>> Pyromancer wrote:
>>>>>> Not sure about this one. On the one hand, making such clothing
>>>>>> mandatory would appear nannying and victim-blaming, on the other it
>>>>>> does make sense to be sure you can be seen.
>>>>> I look forward to the mandatory painting of cars dayglo orange.
>>>> Given we insist on trains having yellow ends for visibility reasons,
>>>
>>> Errr no, that was purely a BR requirement for diesel and electric
>>> locomotives. It doesn't affect other railways.
>>>
>>>> it could be argued that all cars should have bright fronts.
>>>
>>> Not a bad idea, except that it wouldn't make any difference to people
>>> who don't bother looking.

>>
>>
>> Hold that thought, now extrapolte to cycles.
>>
>> If someone is not looking there is no point in wearing dayglo, if they
>> are looking there is no point in wearing dayglo.

>
> Of course there is a point to dayglo clothing, all the H&S officers at
> all these tinpot companies need something to feel important about.


It's a way of having a cast iron excuse for sacking somone. You can't
argue with H&S as a reason.
 
®i©ardo wrote:
> Tony Raven wrote:
>> Mortimer wrote:
>>
>>>
>>> I'm surprised we don't have a rule in the UK making lights a
>>> compulsory part of a bike.

>>
>> The law has far more important things to do like mandating a bicycle
>> bell at the point of sale ;-)
>>
>> Tony

>
> Even that could be useful if people learned how to use it.
>
> ;-)
>

NVQ course in bicycle bell operations and safety. :-
 
On Aug 14, 11:08 am, NM <[email protected]> wrote:
> Tony Raven wrote:
> > NM wrote:

>
> >>> I have one and it is calibrated pretty accurately. Few cyclists are
> >>> travel as slow as 10mph and I am usually between 15-20mph dropping to
> >>> maybe 8 or 9 on steeper hills. Next?

>
> >> How did you get it calibrated?

>
> > Very easy. Cycle computers are nothing more than wheel revolution
> > counters which multiply the number of revolutions per second by the user
> > entered wheel circumference. Measure the circumference in a roll out
> > test, enter it and voila, calibrated speedometer. Most of us here will
> > have done that and its good to about 0.1mph from cross calibration with
> > GPS on a straight road.

>
> A roll out test? I assume you mean you push the bike for one wheel
> revolution measure the distance, do a bit of maths? Do you correct for
> the difference in rolling diameter between a loaded and an empty bike or
> don't you go to that level of accuracy?



Yes. You do it loaded. Doing it unloaded will overestimate the speed
by up to 2%.

Mine is not particularly well calibrated but still gets within 3% on a
measured course.

...d
 
®i©ardo wrote:
> Tony Raven wrote:
>> Mortimer wrote:
>>
>>>
>>> I'm surprised we don't have a rule in the UK making lights a
>>> compulsory part of a bike.

>>
>> The law has far more important things to do like mandating a bicycle
>> bell at the point of sale ;-)
>>
>> Tony

>
> Even that could be useful if people learned how to use it.


Yes, if fitted with a quick release so that you could throw it at a
driver to attract their attention.
 
On Aug 14, 11:15 am, ®i©ardo <[email protected]> wrote:
> Tony Raven wrote:
> > ®i©ardo wrote:

>
> >> When I walk the lanes in the dark to my local I always wear a
> >> fluorescent waistcoat and I walk facing the oncoming traffic, although
> >> that isn't too relevant given the width of some of the roads. I don't
> >> see what the problem is, unless cycling is such a "fashion statement"
> >> that you don't want to be shown up, or show up.

>
> > I presume you paint your car fluorescent orange too. If not why not, it
> > can't just be a fashion thing surely?

>
> > Tony

>
> No, my car is metallic bronze and it has lights on it, which I use in
> appropriate weather conditions or to meet the requirements of the time
> of day/night.


My bike is bright red and it has lights on it yada yada yada

So why do I need to wear light clothing again?

Can't you see my lights?

If you can't then what hope do you have of being able to see me?

...d
 
NM wrote:

>
> A roll out test? I assume you mean you push the bike for one wheel
> revolution measure the distance, do a bit of maths? Do you correct for
> the difference in rolling diameter between a loaded and an empty bike or
> don't you go to that level of accuracy?


No maths, just mark the tyre and roll it out along a tape for one turn
of the wheel to get the circumference. And yes for best accuracy you
need to do it loaded and with the tyres at your normal pressure. But to
within the accuracy of knowing whether its 9 or 11mph, which is I
believe Firth's point, none of that level of care is needed and the
manufacturer's standard setting is good enough.

Tony
 
Steve Firth wrote:
> Tony Raven <[email protected]> wrote:
>
>> Steve Firth wrote:
>>>> The cyclist could have been travelling at 10mph or less. This is as
>>>> unlikely, as even most trundlies potter about at more than that.
>>> Most cyclists grossly over estimate their speed, few have speedometers
>>> and none of thsoe are calibrated.

>> I have one and it is calibrated pretty accurately.

>
> And how do you know this?


I check mine about once a month against my GPS.

The initial calibration I checked against my measured mile that I set
up for calibrating my Halda.

My Halda I check at the start of every rally against the organisers
measured mile.

My measured mile I set up using a surveyors wheel which I borrowed off
my friend who works for the LA, he checked it against the LA's standard.

Whenever I pass my measured mile I check the calibration of time taken
and distance covered, the measurement has never differed by more than 1%.
 
Steve Firth wrote:
>> I have one and it is calibrated pretty accurately.

>
> And how do you know this?


Because I calibrated it using time honoured methods of calibration in
which I am well versed. True I made some assumptions such as the tape
measure I used being accurately calibrated by the manufacturer.

Tony
 
®i©ardo wrote:
> Tony Raven wrote:
>> ®i©ardo wrote:
>>>
>>> When I walk the lanes in the dark to my local I always wear a
>>> fluorescent waistcoat and I walk facing the oncoming traffic,
>>> although that isn't too relevant given the width of some of the
>>> roads. I don't see what the problem is, unless cycling is such a
>>> "fashion statement" that you don't want to be shown up, or show up.
>>>

>>
>> I presume you paint your car fluorescent orange too. If not why not,
>> it can't just be a fashion thing surely?
>>
>> Tony

>
> No, my car is metallic bronze and it has lights on it, which I use in
> appropriate weather conditions or to meet the requirements of the time
> of day/night.
>


So if I have lights on my bike (which I do) and use them "in appropriate
weather conditions or to meet the requirement of day/night" there is no
problem with my being seen without wearing fluorescent clothing in just
the same way that there is not with your non-fluorescent painted car?

Tony
 
In message <[email protected]>
"The other view point, there is one you know...http://www.highwaycode.gov.uk/03.htm" <[email protected]> wrote:

> On 14 Aug, 10:25, Mike Clark <[email protected]> wrote:
> > In message <[email protected]>
> > "The other view point, there is one you know...http://www.highwaycode.gov.uk/03.htm" <[email protected]> wrote:
> >
> > [snip]
> >
> >
> >
> > > If I was to believe bike safety facts that I have been used in this
> > > group.

> >
> > > I would have come to the conclusion that;
> > > Helmets kill, it's safer to ride a bike that walk and safer to ride on
> > > the road than a cycle path.

> >
> > > Not much commonsense around is there....

> >
> > Common sense is often far from sensible and sensible solutions are
> > often counter-intuitive. What I can tell you as medical researcher is
> > that the RTA statistics support the views you have stated above.
> >
> > Mike

>
> RTA are usually only recorded if KSI
>
> I want to see A&E stats.
>


If you want to see a comparison of Hospital A&E admissions versus Police
RTA data there are publications available. You don't need to bleat about
it on the newsgroup, just start reading the relevant medical
publications.

e.g. http://injuryprevention.bmj.com/cgi/content/abstract/7/3/234

Investigation of bias after data linkage of hospital admissions data to
police road traffic crash reports. Injury Prevention 2001; 7:234-241

Mike
--
o/ \\ // |\ ,_ o Mike Clark
<\__,\\ // __o | \ / /\, "A mountain climbing, cycling, skiing,
"> || _`\<,_ |__\ \> | immunology lecturer, antibody engineer and
` || (_)/ (_) | \corn computer user"
 
David Martin wrote:
>
> Yes. You do it loaded. Doing it unloaded will overestimate the speed
> by up to 2%.
>
> Mine is not particularly well calibrated but still gets within 3% on a
> measured course.
>


Which compares with the -0/+10% accuracy required by law of a car speedo.

Tony
 
Tony Raven <[email protected]> wrote:

> NM wrote:
> >>
> >> I have one and it is calibrated pretty accurately. Few cyclists are
> >> travel as slow as 10mph and I am usually between 15-20mph dropping to
> >> maybe 8 or 9 on steeper hills. Next?
> >>

> >
> > How did you get it calibrated?

>
> Very easy.


Short summary, it's not calibrated.
 
Mark T
<pleasegivegenerously@warmail*turn_up_the_heat_to_reply*.com.invalid>
wrote:

> >> The cyclist could have been travelling at 10mph or less. This is as
> >> unlikely, as even most trundlies potter about at more than that.

> >
> > Most cyclists grossly over estimate their speed

>
> Whilst the speedometer on my bike isn't independently calibrated, it is
> pretty accurate.


Uh huh, and the speedometer on muy car is "pretty accurate". It only
over-reads the speed by about 10%+ 2 mph.
 
®i©ardo wrote:
> Tony Raven wrote:
>> Mortimer wrote:
>>
>>>
>>> I'm surprised we don't have a rule in the UK making lights a
>>> compulsory part of a bike.

>>
>> The law has far more important things to do like mandating a bicycle
>> bell at the point of sale ;-)
>>
>> Tony

>
> Even that could be useful if people learned how to use it.
>
> ;-)
>


And more importantly learned how to hear it. I've lost count of the
number of time I have been berated for not having a bell having spent
several seconds previously ringing it to no effect other than
occasionally somebody checking whether their mobile phone was ringing.

Tony
 
marc <[email protected]> wrote:

> Steve Firth wrote:
> > Tony Raven <[email protected]> wrote:
> >
> >> Steve Firth wrote:
> >>>> The cyclist could have been travelling at 10mph or less. This is as
> >>>> unlikely, as even most trundlies potter about at more than that.
> >>> Most cyclists grossly over estimate their speed, few have speedometers
> >>> and none of thsoe are calibrated.
> >> I have one and it is calibrated pretty accurately.

> >
> > And how do you know this?

>
> I check mine about once a month against my GPS.


Is your name "Tony Raven"?
 
Tony Raven <[email protected]> wrote:

> Steve Firth wrote:
> >> I have one and it is calibrated pretty accurately.

> >
> > And how do you know this?

>
> Because I calibrated it using time honoured methods of calibration in
> which I am well versed.


A simple "it's not calibrated" would have been sufficient.
 
Mark T wrote:
>> I don't
>> see what the problem is, unless cycling is such a "fashion statement"
>> that you don't want to be shown up, or show up.

>
> Do you really think that a cyclist, who is already higher than most cars;
> with front, rear and pedal reflectors plus lights does not show up?


What "front, rear and pedal reflectors plus lights"? You're living in a
dream world, or you probably live in a town with brightly lit roads with
the alternative of plenty of pavements to cycle on.

>
> Do you wear reflectives when walking around town? What is the problem? Do
> you not want to show up?


Not if I'm not walking in the middle of the road, no.
>



--
Moving things in still pictures!
 

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