Rhyll inquest starts



Dylan Smith wrote:
> On 2007-06-05, marc <[email protected]> wrote:
>> Not necessarily narrow better than wide, but higher pressure/sq mm is
>> better that lower, which has the higher bike or car?

>
> The bike, by a staggering margin. My car exerts a pressure of around 35
> lbs/sq. on its ground contact area with properly inflated tyres. My bike
> on the other hand exerts a pressure on the ground of around 110 lbs
> sq.in on the rear and 90 lbs sq in. on the front tyre.


Does that mean that your bike damages the road surface (as opposed to
the underlying structure) more than your car - like hard stiletto heels
damage vinyl and wooden floors more than flat soft heels do?

--
Matt B
 
In article <[email protected]>, Matt B
"matt.bourke"@nospam.london.com says...
> Dylan Smith wrote:
> > On 2007-06-05, marc <[email protected]> wrote:
> >> Not necessarily narrow better than wide, but higher pressure/sq mm is
> >> better that lower, which has the higher bike or car?

> >
> > The bike, by a staggering margin. My car exerts a pressure of around 35
> > lbs/sq. on its ground contact area with properly inflated tyres. My bike
> > on the other hand exerts a pressure on the ground of around 110 lbs
> > sq.in on the rear and 90 lbs sq in. on the front tyre.

>
> Does that mean that your bike damages the road surface (as opposed to
> the underlying structure) more than your car - like hard stiletto heels
> damage vinyl and wooden floors more than flat soft heels do?
>
>

Surface wear is caused by vehicles accelerating - that's why it's most
evident at junctions, crossings and bends. Bicycles don't have enough
mass to cause much (any?) damage.
 
Rob Morley wrote:
> In article <[email protected]>, Matt B
> "matt.bourke"@nospam.london.com says...
>> Dylan Smith wrote:
>>> On 2007-06-05, marc <[email protected]> wrote:
>>>> Not necessarily narrow better than wide, but higher pressure/sq mm is
>>>> better that lower, which has the higher bike or car?
>>> The bike, by a staggering margin. My car exerts a pressure of around 35
>>> lbs/sq. on its ground contact area with properly inflated tyres. My bike
>>> on the other hand exerts a pressure on the ground of around 110 lbs
>>> sq.in on the rear and 90 lbs sq in. on the front tyre.

>> Does that mean that your bike damages the road surface (as opposed to
>> the underlying structure) more than your car - like hard stiletto heels
>> damage vinyl and wooden floors more than flat soft heels do?
>>

> Surface wear is caused by vehicles accelerating - that's why it's most
> evident at junctions, crossings and bends. Bicycles don't have enough
> mass to cause much (any?) damage.


Would a 35psi car, or a 110psi bike make more of an impression on the
surface of a bowling green, if driven/ridden across one at a constant speed?

--
Matt B
 
In article <[email protected]>, Matt B
"matt.bourke"@nospam.london.com says...
> Rob Morley wrote:
> > In article <[email protected]>, Matt B
> > "matt.bourke"@nospam.london.com says...
> >> Dylan Smith wrote:
> >>> On 2007-06-05, marc <[email protected]> wrote:
> >>>> Not necessarily narrow better than wide, but higher pressure/sq mm is
> >>>> better that lower, which has the higher bike or car?
> >>> The bike, by a staggering margin. My car exerts a pressure of around 35
> >>> lbs/sq. on its ground contact area with properly inflated tyres. My bike
> >>> on the other hand exerts a pressure on the ground of around 110 lbs
> >>> sq.in on the rear and 90 lbs sq in. on the front tyre.
> >> Does that mean that your bike damages the road surface (as opposed to
> >> the underlying structure) more than your car - like hard stiletto heels
> >> damage vinyl and wooden floors more than flat soft heels do?
> >>

> > Surface wear is caused by vehicles accelerating - that's why it's most
> > evident at junctions, crossings and bends. Bicycles don't have enough
> > mass to cause much (any?) damage.

>
> Would a 35psi car, or a 110psi bike make more of an impression on the
> surface of a bowling green, if driven/ridden across one at a constant speed?
>

That's irrelevant. It's also the end of this discussion as far as I'm
concerned.
<goes away to check message filters>
 
On 6 Jun, 07:34, Tony B <[email protected]> wrote:
> marc wrote:
> >> higher pressure/sq mm is better that lower, which has the higher bike or car?

>
> Are you sure that's right?

Very, have a look at any specialist snow tyre for a rally car tall and
narrow with very stiff sidewalls

When riding on mud lower tyre pressures
> increase traction. Ever seen trials riders?


Often but then you have a surface to grip, the idea of highpressure,
narrow footprint it to cut through the snow to get more grip, and if
you have a high pressure pootprint you melt the very thin layer of ice
and get mechanical grip from the road surface


> Also, narrow tyred cars (eg
> my old 106) drive better on snow than wide tyres (eg my rather larger
> 307). Cycle tyres are very narrow and do well on snow, notwithstanding
> the single-track vehicle aspect. I am informed the old Model T was great
> on icy roads with it's pram wheels...


You trying to make my case for me?
The Model T had narrow tyres and low weight , compare that tyre width
and weight to a modern car.
>
> T
 
On Wed, 6 Jun 2007 12:13:07 +0100, Rob Morley <[email protected]>
wrote:

>In article <[email protected]>, Matt B
>"matt.bourke"@nospam.london.com says...
>> Rob Morley wrote:
>> > In article <[email protected]>, Matt B
>> > "matt.bourke"@nospam.london.com says...
>> >> Dylan Smith wrote:
>> >>> On 2007-06-05, marc <[email protected]> wrote:
>> >>>> Not necessarily narrow better than wide, but higher pressure/sq mm is
>> >>>> better that lower, which has the higher bike or car?
>> >>> The bike, by a staggering margin. My car exerts a pressure of around 35
>> >>> lbs/sq. on its ground contact area with properly inflated tyres. My bike
>> >>> on the other hand exerts a pressure on the ground of around 110 lbs
>> >>> sq.in on the rear and 90 lbs sq in. on the front tyre.
>> >> Does that mean that your bike damages the road surface (as opposed to
>> >> the underlying structure) more than your car - like hard stiletto heels
>> >> damage vinyl and wooden floors more than flat soft heels do?
>> >>
>> > Surface wear is caused by vehicles accelerating - that's why it's most
>> > evident at junctions, crossings and bends. Bicycles don't have enough
>> > mass to cause much (any?) damage.

>>
>> Would a 35psi car, or a 110psi bike make more of an impression on the
>> surface of a bowling green, if driven/ridden across one at a constant speed?


I've seen the damage cars, tractors, bicycles, snowmobiles, horses, and
baby buggies do to soft ground. It's all a muddy mess. What's your
point?
 
Marc Brett wrote:
> On Wed, 6 Jun 2007 12:13:07 +0100, Rob Morley <[email protected]>
> wrote:
>
>> In article <[email protected]>, Matt B
>> "matt.bourke"@nospam.london.com says...
>>> Rob Morley wrote:
>>>> In article <[email protected]>, Matt B
>>>> "matt.bourke"@nospam.london.com says...
>>>>> Dylan Smith wrote:
>>>>>> On 2007-06-05, marc <[email protected]> wrote:
>>>>>>> Not necessarily narrow better than wide, but higher pressure/sq mm is
>>>>>>> better that lower, which has the higher bike or car?
>>>>>> The bike, by a staggering margin. My car exerts a pressure of around 35
>>>>>> lbs/sq. on its ground contact area with properly inflated tyres. My bike
>>>>>> on the other hand exerts a pressure on the ground of around 110 lbs
>>>>>> sq.in on the rear and 90 lbs sq in. on the front tyre.
>>>>> Does that mean that your bike damages the road surface (as opposed to
>>>>> the underlying structure) more than your car - like hard stiletto heels
>>>>> damage vinyl and wooden floors more than flat soft heels do?
>>>>>
>>>> Surface wear is caused by vehicles accelerating - that's why it's most
>>>> evident at junctions, crossings and bends. Bicycles don't have enough
>>>> mass to cause much (any?) damage.
>>> Would a 35psi car, or a 110psi bike make more of an impression on the
>>> surface of a bowling green, if driven/ridden across one at a constant speed?

>
> I've seen the damage cars, tractors, bicycles, snowmobiles, horses, and
> baby buggies do to soft ground. It's all a muddy mess. What's your
> point?


I wasn't trying to make a point. I was asking a question, the answer to
which would have been a valuable contribution to the discussion that was
going on about tyre pressure, its effect on grip, ice penetration, etc.
Do you know the answer?

--
Matt B
 
On 2007-06-06, Matt B <"matt.bourke"@nospam.london.com> wrote:
> Does that mean that your bike damages the road surface (as opposed to
> the underlying structure) more than your car - like hard stiletto heels
> damage vinyl and wooden floors more than flat soft heels do?


No. On a hard surfaced road, road wear goes up at roughly between the
third and fourth power of axle weight for any sane tyre pressure.
If a 2 axle car does one unit of wear, a large articulated lorry,
depending on loading, will cause between 8,000 and 150,000 times
more wear to the road. It's about the same order of magnitude difference
between a bicycle and a car.

With the very light weight of a bicycle, even at 200 psi, the road wear
caused by the bike will be immeasurably small compared to a typical
family car.

--
Yes, the Reply-To email address is valid.
Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de
 
Matt B wrote:
> I wasn't trying to make a point. I was asking a question, the answer to
> which would have been a valuable contribution to the discussion that was
> going on about tyre pressure, its effect on grip, ice penetration, etc.


Why, did the incident take place on a bowling green? I don't think I
saw that in the news reports.

> Do you know the answer?


I cycle so rarely on bowling greens, I regret that I can't help here.


-dan
 
Dylan Smith wrote:
> On 2007-06-06, Matt B <"matt.bourke"@nospam.london.com> wrote:
>> Does that mean that your bike damages the road surface (as opposed to
>> the underlying structure) more than your car - like hard stiletto heels
>> damage vinyl and wooden floors more than flat soft heels do?

>
> No. On a hard surfaced road, road wear goes up at roughly between the
> third and fourth power of axle weight for any sane tyre pressure.


IIRC, that is the formula for sub-structure damage. I was talking about
surface deformation really, not even surface "wear". To understand how
black-ice might react.

> If a 2 axle car does one unit of wear, a large articulated lorry,
> depending on loading, will cause between 8,000 and 150,000 times
> more wear to the road. It's about the same order of magnitude difference
> between a bicycle and a car.


Interesting, yes. And using that formula, a typical bus passenger
inflicts at least 300 times as much damage as a typical car passenger.

--
Matt B
 
On Jun 6, 1:18 pm, Matt B <"matt.bourke"@nospam.london.com> wrote:
>
> IIRC, that is the formula for sub-structure damage. I was talking about
> surface deformation really, not even surface "wear". To understand how
> black-ice might react.
>

On a road there won't be any significant difference in surface
deformation between a bike and a car. (To all intents and purposes
both is zero)

At rest on a very soft surface the bike (with rider) will cause a
bigger dent. Without rider it's probably not heavy enough to deform a
surface that is capable of supporting a car at all.

One they are both attempting to travel at constant speed I've no idea
which will cause the bigger damage. Both will be being pushed by the
driven wheels. On a waterlogged bowling green the driven wheels are
likely to slip on both bike and car and this will cause most of the
damage.

I've no idea what happens on ice.

Tim.
 
On Jun 5, 9:56 pm, marc <[email protected]> wrote:
> Helen Deborah Vecht wrote:
> > marc <[email protected]>typed

>
> >> Helen Deborah Vecht wrote:
> >>> marc <[email protected]>typed

>
> >>>> tyres were
> >>>>>> bald or brand new. It's a question of ice on the road."

>
> >>>>>> It's looking very shoddy so far, day one of a four-person inquest and
> >>>>>> he's already directing the jury toward accidental death with
> >>>>>> contributory negligence to the victims for having the temerity to
> >>>>>> go out.

>
> >>>>>> *******.

>
> >>>>>> Tony B
> >>>>> Agreed, blatant leading. A defective car travelling too fast kills
> >>>>> four people and the authorities imply blame on the victims
> >>>>> for....being there.

>
> >>>> Too fast for what?
> >>> Too fast to hold the road on a frosty morning, with fatal results.

>
> >>> It is hardly surprising thay ice forms when temperatures drop below
> >>> freezing point. Travelling at 50mph on a bendy road in ice, then blame
> >>> the victims or the council. This attitude STINKS!

>
> >> So eveyone agrees that the road was icy, dangerous, it wasn't
> >> suprising that there was ice on the road? Would it be fair then to ask
> >> , why was a club using a dangerous road, covered in ice?
> >> The inquest is to find out what happened, not to crucify drivers or
> >> salve concsiences.

>
> >> What does stink is people forming lynch mobs before the legal processes
> >> are finished.

>
> > The victims did not fail to control their vehicles. The driver did.
> > Please do not blame the victims.

>
> A number of drivers that morning had difficulty controlling their
> vehicles, if the club run had reached the same spot, Im sure that they
> would have done also, the only difference that I can see is that one
> driver lost control at the same time that the space that was needed to
> regain control was occupied.
>
> If the road was dangerous, every road user was as much to "blame" for
> using it, or was not to blame because they coudn't have known, that
> includes the police driver , the club captain, and Robert Harris.
>
> What hasn't been decided is , was the road dangerous?


Let us assume for a moment that it was forseeable that the road was
icy to the extent that a wheeled vehicle could expect to risk losing
traction at some point for soem distance. In that case then other
drivers who travelled at a speed that meant that if they loast
control, then their vehicle would represent a danger to other usets
are equally culpable regardless of the outcome. The degree of
culpability would vary with speed, handling characteristics under low
or no traction, visibility and sightlines at a given point (it would
be more reasonable to proceed with a greater chance of loss of control
if it could be seen that there was no other road user present to be
affected by a loss of control), vehicle mass and probably some other
similar factors. In crude terms, car drivers (unless traveling at
extremely low speed) presented a greater danger to other road users
that cyclists traveling at typical cycling speeds.

If you mean that the club captain could or should have anticipated
that other road users would be negligent or incompetent in their risk
assessments and or driving strategies for the day then that is
possible (given the first assumption) but cannot make him culpable for
the outcome

best wishes
james
 
On Tue, 05 Jun 2007, marc <[email protected]> wrote:

> A number of drivers that morning had difficulty controlling their
> vehicles,


No other vehicle had such difficulty that they ran off the road,
bounced off a wall and then up the opposite bank. This driver did,
and was clearly driving with a much lower standard of care than the
other drivers.

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|
 
On Wed, 06 Jun 2007 11:35:44 +0100, Matt B wrote:
> Dylan Smith wrote:
> > On 2007-06-05, marc <[email protected]> wrote:
> >> Not necessarily narrow better than wide, but higher pressure/sq mm is
> >> better that lower, which has the higher bike or car?

> >
> > The bike, by a staggering margin. My car exerts a pressure of around 35
> > lbs/sq. on its ground contact area with properly inflated tyres. My bike
> > on the other hand exerts a pressure on the ground of around 110 lbs
> > sq.in on the rear and 90 lbs sq in. on the front tyre.

>
> Does that mean that your bike damages the road surface (as opposed to
> the underlying structure) more than your car



No, because as has been pointed out to you ad nauseum in the past,
road damage is not closely related to tyre pressure, but is more
closely correlated with axle load (or wheel group load).

You've been told this before. You ignored it before, no doubt you
will ignore it again, however in this (rare) case, I think the
disbenefit of acknowledging you exist is outweighed by highlighting
that you're talking bollocks again.

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|
 
On Wed, 06 Jun 2007 05:38:12 -0700 someone who may be
"[email protected]" <[email protected]> wrote this:-

>Let us assume for a moment that it was forseeable that the road was
>icy to the extent that a wheeled vehicle could expect to risk losing
>traction at some point for soem distance. In that case then other
>drivers who travelled at a speed that meant that if they loast
>control, then their vehicle would represent a danger to other usets
>are equally culpable regardless of the outcome.


Feel free to indicate the number of other motorists that lost
control of their motor vehicle and bounced it off a wall in the
area. I suspect that you will find that the answer is a round
number.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54
 
In news:p[email protected],
David Hansen <[email protected]> tweaked the Babbage-Engine to
tell us:
> On Wed, 06 Jun 2007 05:38:12 -0700 someone who may be
> "[email protected]" <[email protected]> wrote this:-
>
>> Let us assume for a moment that it was forseeable that the road was
>> icy to the extent that a wheeled vehicle could expect to risk losing
>> traction at some point for soem distance. In that case then other
>> drivers who travelled at a speed that meant that if they loast
>> control, then their vehicle would represent a danger to other usets
>> are equally culpable regardless of the outcome.

>
> Feel free to indicate the number of other motorists that lost
> control of their motor vehicle and bounced it off a wall in the
> area. I suspect that you will find that the answer is a round
> number.



"Mr Hughes [the coroner] also said there had been another accident near the
scene on the same morning, and the police had been in touch with the council
about conditions on the road."

--
Dave Larrington
<http://www.legslarry.beerdrinkers.co.uk>
And then there was light and He thought it was good, so He threw
the receipt away.
 
On Wed, 06 Jun 2007 12:43:00 +0100, Matt B
<"matt.bourke"@nospam.london.com> wrote:

>>>> Would a 35psi car, or a 110psi bike make more of an impression on the
>>>> surface of a bowling green, if driven/ridden across one at a constant speed?

>>
>> I've seen the damage cars, tractors, bicycles, snowmobiles, horses, and
>> baby buggies do to soft ground. It's all a muddy mess. What's your
>> point?

>
>I wasn't trying to make a point. I was asking a question, the answer to
>which would have been a valuable contribution to the discussion that was
>going on about tyre pressure, its effect on grip, ice penetration, etc.
> Do you know the answer?


No. But I'm still struggling to see how discussing performance of tyres
on soft grass has anything to do with a case involving tarmac and ice.
 
Marc Brett wrote:
> On Wed, 06 Jun 2007 12:43:00 +0100, Matt B
> <"matt.bourke"@nospam.london.com> wrote:
>
>>>>> Would a 35psi car, or a 110psi bike make more of an impression on the
>>>>> surface of a bowling green, if driven/ridden across one at a constant speed?
>>> I've seen the damage cars, tractors, bicycles, snowmobiles, horses, and
>>> baby buggies do to soft ground. It's all a muddy mess. What's your
>>> point?

>> I wasn't trying to make a point. I was asking a question, the answer to
>> which would have been a valuable contribution to the discussion that was
>> going on about tyre pressure, its effect on grip, ice penetration, etc.
>> Do you know the answer?

>
> No. But I'm still struggling to see how discussing performance of tyres
> on soft grass has anything to do with a case involving tarmac and ice.


I thought it would help understand the nature of surfaces, and surface
deformation. It is hard to imagine how ice or tarmac might react under
different pressures because we cannot "see" the minute deformations that
might be taking place. On grass though we have probably all experienced
the different effects of different pressures. Perhaps firm wet sand,
like on the beach when the tide has gone out, would be easier to visualise.

--
Matt B
 
Ian Smith wrote:
> On Wed, 06 Jun 2007 11:35:44 +0100, Matt B wrote:
>> Dylan Smith wrote:
>>> On 2007-06-05, marc <[email protected]> wrote:
>>>> Not necessarily narrow better than wide, but higher pressure/sq mm is
>>>> better that lower, which has the higher bike or car?
>>> The bike, by a staggering margin. My car exerts a pressure of around 35
>>> lbs/sq. on its ground contact area with properly inflated tyres. My bike
>>> on the other hand exerts a pressure on the ground of around 110 lbs
>>> sq.in on the rear and 90 lbs sq in. on the front tyre.

>> Does that mean that your bike damages the road surface (as opposed to
>> the underlying structure) more than your car

>
>
> No, because as has been pointed out to you ad nauseum in the past,
> road damage is not closely related to tyre pressure, but is more
> closely correlated with axle load (or wheel group load).


As we've said already, to the sub-structure of the road maybe, but this
discussion was about surface deformation. I am trying to understand if
black-ice would be more likely to be penetrated by a narrow, high
pressure tyre, than by a wider, lower pressure tyre. And presumably, if
the former has more impact on ice, then it would also have more impact
on the top layer of the actual road surface.

> You've been told this before. You ignored it before, no doubt you
> will ignore it again, however in this (rare) case,


In relation to suface deformation? Are you sure?

> I think the
> disbenefit of acknowledging you exist is outweighed by highlighting
> that you're talking bollocks again.


The question was valid - and other contributors have suggested that soft
surface deformation is likely to be greater with the narrow, higher
pressure tyres.

Why are you being so confrontational over this? Are you worried that
the answer may reveal an uncomfortable truth?

--
Matt B
 
Marc Brett wrote:
>
> And more police manipulation, regarding the bald tyres:
>
> http://www.dailymail.co.uk/pages/li...1&in_page_id=1770&in_page_id=1770&expand=true
>
> "RoadPeace agreed and said Harris could have been charged with driving
> without due care and attention in relation to the bald tyres.
>
> "Such charges, however, must be laid down within six months of an
> accident but the police failed to announce the tyres were defective
> until 26 weeks after the crash, by which time it was too late, Miss
> Aeron-Thomas said. "


Is that obstructing the course of justice?.