On Mon, 25 Jun 2018 10:30:33 +0100, Robin wrote:

On 25/06/2018 10:12, T i m wrote:
snip

So, a right brainer would take these sorts of things and then try to
look for a scientific / mathematic solution as to why this is.

A left brainer would jump to a conclusion based on their lack of
understanding and then look for information to support their denial
(from other left brainers typically). ;-)


I don't think it helps to introduce another myth[1] - let alone a mirror
image of the usual one

[1] http://www.oecd.org/education/ceri/neuromyth6.htm

sigh Back to my 'real world' right brainer approach ...

Do you think we fully understand the inner workings of the human brain
Robin?

Do you concede that the brain *is* made up of two physically separate
hemispheres that are only joined together at one point?

Do you concede that is someone has a stroke, they typically lose
different functions, depending on what side it occurs in?

Do you concede that most people are 'handed' and will have a dominant
hand / leg / eye [1]?

Do you concede that there are many studies that have proven that
certain things *are* either typically permanently centred or even
focused in one hemisphere or the other.

Do you understand the concept of 'brain lateralisation / dominance'
and what that actually means ITRW?

So, rather than reading (and believing) the opinions of someone who
may well be a (closed mind) left brainer in denial g, how about
reading some *real* medical science on the matter?

"The notion of different hemispheric thinking styles is based on an
erroneous premise: each brain hemisphere is specialised and therefore
each must function independently with a different thinking style."

Bwhahahahaha! Whoosh! ;-)

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3767540/

Cheers, T i m

[1] If you don't know which brain driven dominant eye is, try this
experiment.

With both eyes open and arm outstretched, point with one finger and a
small object in the distance.

Holding your arm still, close each eye in turn and note which one
leaves the object in alignment with your finger and (therefore) which
one doesn't. The one that stays aligned is your 'lead / dominant' eye.

Now, assuming a reasonably balanced quality of vision in both eyes, do
you think it's the actual eye that is taking control over the other or
that maybe that hemisphere of the brain that is being 'dominant'?

Quiz for you then.

Are our sight functions lateralised?

Are our smell functions lateralised?

Are our hearing functions lateralised?

Are our taste functions lateralised?

And if not, why not?

"Tim Lamb" wrote in message
...
In message , Jeff
writes


"Chris Hogg" wrote in message
. ..
On Mon, 25 Jun 2018 15:50:06 +1000, "Jeff" wrote:



Yes, but it is the distance between the axle and the road
that determines the rotation rate.

If the length of the perimeter of the tyre is say 1.5 metres, and the
vehicle is travelling at 150 km/hr, that means the tyre rotates 100000
times per hour, or 1666.6 rpm, assuming no slippage between tyre and
road or tyre and rim. There's no getting around that, and there's no
mention of state of inflation, shape of the tyre or axle to road
distance.

Yes, but it is the distance between the axle and the road
that determines the rotation rate.

Why?

Because that's how the physics works. And that should be obvious from
what happens with wheels with no tyre, with different diameter wheels.

Long time since 'O' level maths but I suspect the relationship between the
radius and the perimeter only works for a perfect circle.

Irrelevant to what determines the rotation rate of the wheel.

And it is very easy to actually measure if the rotation rate of the wheel
does in fact vary with the distance between the axle and the road. when
you vary the pressure in the tyre. Not clear if any OBD2 system does in
fact report the rotation rate of each wheel using the ABS sensor on each
wheel, but if they do, that would be very easy to do the experiment with.

On Mon, 25 Jun 2018 10:35:49 +0100, "Dave Plowman (News)"
wrote:

snip

Seems lots on here can't understand the concept of one wheel running at
different RPM from the others. Perhaps they only ever drive in a straight
line.

Have you noticed any links between the inability to understand this
concept and their known stance on Brexit?

I'd say that from my quick poll (and you know how reliable they are
g) so far it's 100%. ;-)

I wonder if the reason they don't like the EU is because it's much
closer to the edge of the world (we in Great Britain are in the middle
of the flat world obviously)?

Maybe there is something to this whole l/r brain dominance thing after
all. ;-)

Cheers, T i m

In article ,
Andy Burns wrote:
Dave Plowman wrote:

Huge wrote:

The - Bits - Of - The - Tyre - Not - In - Contact - With - The - Road -
Are - Irrelevant. The - Only - Thing - That - Matters - Is - The -
Diameter - Of - The - Circle - Whose - Radius - Is - The - Distance -
From - The - Axle - To. The - Road.

You should have used caps, Huge. For those whose physics are still at
kindergarten level.

Except there isn't a single distance from the centre of the axle to all
parts of the tyre in contact with the road ... the average distance
perhaps?

Quite. Not the average radius of the tyre, but the average of the part in
contact with the road. Which will, of course squirm around a bit. One
reason why an under inflated tyre wears out more quickly.

--
*No hand signals. Driver on Viagra*

Dave Plowman London SW
To e-mail, change noise into sound.

"Jeff" wrote in message
...
Yes, but it is the distance between the axle and the road
that determines the rotation rate.

Why?

Because that's how the physics works. And that should be obvious from
what happens with wheels with no tyre, with different diameter wheels.

Long time since 'O' level maths but I suspect the relationship between
the radius and the perimeter only works for a perfect circle.

Irrelevant to what determines the rotation rate of the wheel.

True, but the easiest way to visualise the rotation rate for a unit distance
travelled is to divide the distance travelled by the circumference to give
the number of wheel revolutions.

However... it all hinges on what the *effective* circumference is: it is the
circumference of an imaginary circle with the same radius as the distance
between centre of the axle and road surface, which will be less than the
no-load radius because the tyre is slightly flattened where it comes in
contact with the road.

I presume this means that if you took a piece of string and passed it round
the circumference of a tyre this value would be smaller than the no-load
circumference because the part that is in contact with the road will be a
flat rather than a curved profile. This assumes that the radius of the rest
of the tyre doesn't increase significantly when a load is applied to the
tyre - presumably this is constrained by the steel reinforcing belts in the
tyre.


I wonder how much smaller the in-contact radius is than the no-load radius:
what sort of proportion is the reduction, typically? I'll have to measure
the actual distance from the centre of the hubcap to the ground, and then
jack the wheel up until it first touches the road and measure again. Note
that you can't measure to a part of the car body because of compression of
springs :-)

Huge wrote:

Andy Burns wrote:

there isn't a single distance from the centre of the axle to all
parts of the tyre in contact with the road ... the average distance perhaps?

This is really, really simple. Why are you all making it so
complicated? (It's the *shortest* distance, obviously. Just draw a bloody
diagram.)

The diagram I linked to yesterday seems suitable

http://the-contact-patch.com/book/road/c2020-the-contact-patch#figure-ERr

The radius of the orange arc showing effective rolling radius is
inbetween the length of OQ and OP, what makes it "obvious" to you that
the shortest distance applies?

In article , Andy Burns
writes
The Natural Philosopher wrote:

Andy Burns wrote:

The Natural Philosopher wrote:

Why would there be monitors on steering angle?

For the stability control system.

All to modern for me.

It's because there are so many inputs available to the electronics,
wheel speeds, steering angle, yaw rate, accelerometer(s), that figuring
out a flat tyre has just become another part of TCB to the ABS unit.

Never seen steering angle sensed yet on any car I've driven.

I thought you have/had a Disco?
Surprising if such a relatively high centre of mass vehicle didn't have
stability control (or whatever LR call it)
Discos have been around for a long time.
--
bert

On Mon, 25 Jun 2018 10:52:30 +0100, "NY" wrote:

"T i m" wrote in message
news
This means that it must be accurately measurable so when a 32 psi tyre
drops it's pressure to 24 psi (23?), it should raise the alarm.

I've found that it triggers the alarm at a much smaller reduction than 25%.
Our Honda developed a very slow puncture and when I checked the tyres, one
was about 0.2 bar (3 psi) lower than it should have been.

I was just suggesting what I understood to be the maximum pressure
drop threshold before such a system *must* indicate. It's good to see
RW systems are much better than that. ;-)

The instructions for calibrating cycle speedos require you to measure
the *loaded* rolling circumference of the wheel bearing the speed
sensor (when it would be easier just to put a tape round the wheel).

How much does the radius of a bike tyre (at the point of contact) decrease
when you sit on the bike.

I think that depends on the type of bike / tyre to some degree
(balloon / racing skin etc).

It's difficult to tell when I'm the one sitting on
the bike so I don't get a side-on view.

Video from your phone?

I think my speedo actually
recommends measuring the (unloaded) circumference by marking a point on the
tyre that is in contact with the ground and rolling the wheel along the
ground until the point is next in contact.

Agreed.

But I agree that *if possible*
you should try to measure the radius under load and *assume* that the whole
tyre is that radius.

You can do it yourself under load. Put the valve at the bottom and pus
something on the ground to align with the valve (screwdriver, tape and
pen mark etc). Then sit on the bike and walk it in a straight line
whilst keeping as much weight off your feet as possible. Stop when you
see the valve near the bottom, get off, adjust the wheel more
accurately if required (by moving the bike forward or backward
slightly) and make the second mark. Measure between said marks.

I've heard is suggested that there is *significant* error between a brand
new tyre and one with a worn tread, though I'd have thought that it was
negligible.

An extreme of that was replacing non-full profile 12" wheels on our
Escort based kitcar with full (80) profile tyres on 14" wheels. I
believe the rolling circumference increased by 30%.

https://www.halfordsautocentres.com/...pth-and-safety

says that a new tyre has about 8 mm tread. If you use it until the tread is
2 mm, and assuming the same pressure in both cases, then the radius has
reduced by 6 mm in a total radius of 635 (for my car's 215/65/15 tyres) so
about 1%. I wonder how much the effective radius varies for an
under-inflated tyre, assuming the trigger level for a sensor is 25% loss of
pressure.

(25% *maximum* pre triggering) ... On these iTPMS's I thought I heard
mention of 'calibrating' the system to what would be considered
'normal' (tyre pressure, tyre size, wear status) and so the alarm
would be a function of that? I know the prescribed pressures in the
rears (particularly) of our vehicles can vary quite a bit because of
load / speed etc.

Any sensor has to be able to distinguish between expected change in radius
due to tyre wear and unexpected due to loss of pressure.

Sure, but if it only triggers at say a 10% variation and tyre wear
would only ever cause a 1% variation you should be good to go. ;-)

Cheers, T i m

bert wrote:

Andy Burns wrote:

I thought you have/had a Disco?
Surprising if such a relatively high centre of mass vehicle didn't
have stability control (or whatever LR call it)

Discos have been around for a long time.

I had a quick search and at least from Disco3 onwards they have a
steering angle sensor, I couldn't see anything either way about earlier
models.

"Huge" wrote in message
...
The diagram I linked to yesterday seems suitable

http://the-contact-patch.com/book/road/c2020-the-contact-patch#figure-ERr

Because it's wrong. In this context, the relevant dimension is O - Q. How
could it be otherwise? I'm afraid this seems so obvious to me that I
cannot
find ways to explain it.

Yes, in Figure 6, I don't understand why the effective radius is not the
distance OQ. Or OP-z, if you prefer. I presume they are allowing for the
fact that the radius varies between maximum OP (at the edge of the contact
patch) and a minimum OQ (at the centre of the contact patch), and that the
effective radius is somewhere between the two and not the minimum OQ.

On Mon, 25 Jun 2018 12:00:05 +0100, Tim Streater
wrote:

In article , Huge
wrote:

snip

One revolution of the wheel has to equal one passage of the tire's
circumference along the road (since the tire does not slip around the
rim and assuming no slip on the road).

It does not though, obviously (or iTPMS systems wouldn't work).

How could it be otherwise?

Science.

Talk of "effective radius" is not relevant.

To you unfortunately it seems. To people who understand these things
it's key.

Cheers, T i m

Tim Streater wrote:

One revolution of the wheel has to equal one passage of the tire's
circumference along the road (since the tire does not slip around the
rim and assuming no slip on the road). How could it be otherwise?

Talk of "effective radius" is not relevant.

So are saying the circumference remains constant, hence the rpm remains
constant, hence iTPMS cannot work?

On Mon, 25 Jun 2018 12:05:03 +0100, Chris Hogg wrote:

snip

and there's no
mention of state of inflation,

But there should be as that's a key variable that affects the
effective 'perimeter length. ;-)

But as others have pointed out in this thread, it's less than 1%. Or
are you saying that 1% is what the argument is about?

I'm not stating anything so specific Chris but yes, that could
possibly be the sort of numbers we are talking about.

How does that relate ITRW. Well, a tyre that is running at a lower
pressure will rotate more time that will relate to a whole mile in
every 100. The point being that 1% doesn't sound like much but a mile
is quite a way (especially if you are walking with a flat spare to a
garage). ;-). ;-)

shape of the tyre or axle to road
distance.

No, but there should be as the shape of the tyre is instrumental in
the calculation.

If the perimeter of the tyre makes one revolution, the vehicle moves
forward by 1.5 metres in my example, regardless of the shape of the
tyre. It could be oval, or even square with each side 0.375 metres,
but only in Michael Bentine's world :-), but the vehicle still only
moves forward 1.5 metres per revolution of the tyre, and with a square
tyre the axle to ground distance would be changing all the time
(giving a very uncomfortable ride!)

Ok, try this (and try to go with the concept rather than the details
for now). Imagine because how a tyre is constructed, steel wires laid
using a parallelogram pattern that 'pantographs' (think pantograph on
an electric train that gets wider as it gets lower) where it touches
the ground and that causes it to widen (width) but because the
material it is widening by has to come from somewhere, it also shrinks
(length = circumference). So, there is a traveling 'shortening' of the
'effective circumference' that is partially dependant on the *amount*
the flexing happens and that is down to the pressure.

On a solid tyre it wouldn't be because you have removed that variable.

Do you also deny the change in tyre diameter on a dragster (and
therefore rpm / mph)?

https://www.youtube.com/watch?v=YViiNxnQTr8

So dragsters use big tyres;

Yes but you are missing how the size (change) is relevant here.

so do earth moving scrapes and dumpers,
even bigger than those on the dragster. https://tinyurl.com/y9krjyv8

See above.

Big tyres rotate more slowly that small tyres, for the same road
speed, except for that dragster where there was rather a lot of
slippage!

There shouldn't be (and the point of having a 'burn out')

(I bet it stank!

Yes. ;-)

Must cost a fortune;

Yes. ;-(

why do they do it?)

To get the rubber hot to give more traction and a better launch.

I
don't see your point.

I know. As others have said, I'm sorry I don't seem able to transfer
the understanding. ;-(


What about this. Imagine some lunar rover module where the 'tyre' is
made up of many completely independent segments.

With the vehicle up on jacks you might measure the effective
circumference of the wheel as the measurement made with a tape drawn
around it.

But put it under load and with it standing on one (sprung) segment.
the RW radius of that segment at that time under that load will be
less. Imagine that reduction in radius being passed round the wheel
segment by segment and you could then see (hopefully) that the
effective circumference would be calculable from the loaded radius and
it *would* be very different from the unloaded one.

Join those segments together on the outside by something plastic, like
say thin balloon rubber and nothing really changes.

Join them with something heavier but with the similar ability to
'give' and you have a pneumatic car tyre. ;-)

But the 'give' in a car tyre, as has been said here by others, is less
than 1% between hard and soft, over and under inflated.

Yes ... ?

Is that the
difference you're considering?

No, I don't think it is, or the iTPMS might not be able to deal with
tyre wear (even though they could from a programming POV etc)..

If so, then OK I agree with you, a
change in tyre pressure will result in a small 1% change in perimeter
length, and will result in a small 1% change in RPM for a given road
speed.

See above (I think it's bigger).

But I got the impression a much bigger difference was being
assumed/discussed.

As long as you are happy with the fact that it does and why, is all
that matters Chris. ;-)

Cheers, T i m

On Mon, 25 Jun 2018 12:04:58 +0100, Andy Burns
wrote:

Tim Streater wrote:

One revolution of the wheel has to equal one passage of the tire's
circumference along the road (since the tire does not slip around the
rim and assuming no slip on the road). How could it be otherwise?

Talk of "effective radius" is not relevant.

So are saying the circumference remains constant, hence the rpm remains
constant, hence iTPMS cannot work?

Yup, he is (obviously), but he's a fanatic Brexiteer so since when has
logic / fact / reason influenced his thinking. ;-)

Cheers, T i m

On 25/06/2018 11:04, T i m wrote:
On Mon, 25 Jun 2018 10:30:33 +0100, Robin wrote:

On 25/06/2018 10:12, T i m wrote:
snip

So, a right brainer would take these sorts of things and then try to
look for a scientific / mathematic solution as to why this is.

A left brainer would jump to a conclusion based on their lack of
understanding and then look for information to support their denial
(from other left brainers typically). ;-)


I don't think it helps to introduce another myth[1] - let alone a mirror
image of the usual one

[1] http://www.oecd.org/education/ceri/neuromyth6.htm

sigh Back to my 'real world' right brainer approach ...


skip long list of leading questions [1]


https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3767540/

I did not say there are no asymmetries between the hemispheres. I do
say that IMLE your generalisation is not shared by the practising
neurosurgeons, neurologists and neuropsychologists I've heard comment
on the matter. You may of course be better qualified than them or have
access to better advice. But there are many others who agree with the
OECD. I am told functional MRI is particularly persuasive in this
regard[2].

But I don't really expect to persuade you. The left-brain/right-brain
myth has become a metaphor for different ways of thinking which may
never die. And it is of course also a wonderful way to peddle
pseudo-psychology - or cast aspersions.


[1] though I must say I thought calling the corpus callosum a "point" a
bit like saying there's only a few dozen lines for calls across the Atlantic

[2] : eg

http://journals.plos.org/plosone/art...l.pone.0071275

"we demonstrate that ...do not result in a subject-specific global brain
lateralization difference that favors one network over the other (i.e.
left-brained or right-brained).


https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3743825/

"Yet our analyses suggest that an individual brain is not €œleft-brained€�
or €œright-brained€� as a global property, but that asymmetric
lateralization is a property of individual nodes or local subnetworks,
and that different aspects of the left-dominant network and
right-dominant network may show relatively greater or lesser
lateralization within an individual. "

--
Robin
reply-to address is (intended to be) valid

On 25/06/2018 12:00, Tim Streater wrote:
In article , Huge
wrote:

On 2018-06-25, Andy Burns wrote:
Huge wrote:

Andy Burns wrote:

there isn't a single distance from the centre of the axle to all
parts of the tyre in contact with the road ... the average distance
perhaps?

This is really, really simple. Why are you all making it so
complicated? (It's the *shortest* distance, obviously. Just draw a
bloody
diagram.)

The diagram I linked to yesterday seems suitable

http://the-contact-patch.com/book/road/c2020-the-contact-patch#figure-ERr


Because it's wrong. In this context, the relevant dimension is O - Q.
How
could it be otherwise?

One revolution of the wheel has to equal one passage of the tire's
circumference along the road (since the tire does not slip around the
rim and assuming no slip on the road). How could it be otherwise?

Talk of "effective radius" is not relevant.


If by "effective radius" you mean the rolling radius it is the only
relevant measure to combine with the angular velocity in order to arrive
at the speed of the vehicle[1]. If you dispute that please post your
equation.

Or of course you could admit that by circumference you mean the rolling
circumference - defined as 2 x Pi x the rolling radius - which changes
with pressure.



--
Robin
reply-to address is (intended to be) valid

In article ,
Andy Burns wrote:
Tim Streater wrote:

One revolution of the wheel has to equal one passage of the tire's
circumference along the road (since the tire does not slip around the
rim and assuming no slip on the road). How could it be otherwise?

Talk of "effective radius" is not relevant.

So are saying the circumference remains constant, hence the rpm remains
constant, hence iTPMS cannot work?

If you were to measure the speed of rotation of the wheel at any single
point on it, that would vary depending on where it was to the road contact
point. Virtually no drive mechanism transmits a perfectly uniform speed
from input to output. There is invariably a degree of 'chatter'.

--
*ONE NICE THING ABOUT EGOTISTS: THEY DON'T TALK ABOUT OTHER PEOPLE.

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman wrote:

If you were to measure the speed of rotation of the wheel at any
single point on it that would vary depending on where it was to the
road contact point.

The ABS sensor will measure the speed multiple times (e.g. 48) per
revolution of the drive shaft, not just a single point.

Virtually no drive mechanism transmits a perfectly uniform speed
from input to output. There is invariably a degree of 'chatter'.

The TPMS operates over a longer period of time, probably minutes rather
than seconds, so over many revolutions of the wheel, likely the numbers
will get averaged out before it decides one wheel is turning faster than
the others enough to flag it up.

"Andy Burns" wrote in message
...
The TPMS operates over a longer period of time, probably minutes rather
than seconds, so over many revolutions of the wheel, likely the numbers
will get averaged out before it decides one wheel is turning faster than
the others enough to flag it up.

It *has* to integrate over a fairly long time and number of rotations to
avoid it being triggered every time the car turns a corner and the outer
wheel rotates faster than the inner wheel. I would imagine (and I've not
done the calculations) that the difference in rotational speed between inner
and outer wheel on a bend will be significantly more than the difference in
rotational speed between a correctly-inflated and an under-inflated wheel,
so any TPMS has to average out this large difference in order to be able to
detect a much smaller one.

On 25/06/18 11:39, bert wrote:
In article , Andy Burns
writes
The Natural Philosopher wrote:

Andy Burns wrote:

The Natural Philosopher wrote:

Why would there be monitors on steering angle?

For the stability control system.

All to modern for me.

It's because there are so many inputs available to the electronics,
wheel speeds, steering angle, yaw rate, accelerometer(s), that
figuring out a flat tyre has just become another part of TCB to the
ABS unit.

Never seen steering angle sensed yet on any car I've driven.

I thought you have/had a Disco?
Surprising if such a relatively high centre of mass vehicle didn't
have stability control (or whatever LR call it)
Discos have been around for a long time.
defenders and freelanders never a disco


--
€œit should be clear by now to everyone that activist environmentalism
(or environmental activism) is becoming a general ideology about humans,
about their freedom, about the relationship between the individual and
the state, and about the manipulation of people under the guise of a
'noble' idea. It is not an honest pursuit of 'sustainable development,'
a matter of elementary environmental protection, or a search for
rational mechanisms designed to achieve a healthy environment. Yet
things do occur that make you shake your head and remind yourself that
you live neither in Joseph Stalins Communist era, nor in the Orwellian
utopia of 1984.€�

Vaclav Klaus

On 25/06/2018 15:05, NY wrote:

It *has* to integrate over a fairly long time and number of rotations to
avoid it being triggered every time the car turns a corner and the outer
wheel rotates faster than the inner wheel.

Or, given that it knows the steering wheel angle, it might chose to
ignore readings during turns.

I would imagine (and I've not
done the calculations) that the difference in rotational speed between
inner and outer wheel on a bend will be significantly more than the
difference in rotational speed between a correctly-inflated and an
under-inflated wheel

I'd say much greater

so any TPMS has to average out this large
difference in order to be able to detect a much smaller one.

On Mon, 25 Jun 2018 13:58:54 +0100, Robin wrote:

snip

I did not say there are no asymmetries between the hemispheres.

Ok ...

I do
say that IMLE your generalisation is not shared by the practising
neurosurgeons, neurologists and neuropsychologists I've heard comment
on the matter.

Assuming you fully understand whatever you are determine to be 'my
generalisation' etc?

You may of course be better qualified than them or have
access to better advice.

Nope, but the information in the scientific, peer tested link I
provided seemed to?

But there are many others who agree with the
OECD.

I'm sure there are ... like the flat-worlders still out there. ;-)

I am told functional MRI is particularly persuasive in this
regard[2].

But I don't really expect to persuade you.

You don't need to Robin as 1) it doesn't really matter to you what I
'believe' and 2) it doesn't matter to me what you believe (or think I
believe) either.

The left-brain/right-brain
myth

Ok. Do you think we (not me of course), fully understand how the human
brain / mind / memory etc works? Do you think you do maybe?

has become a metaphor for different ways of thinking which may
never die.

It's true that I sometimes like to use it when thinking out loud to
differentiate different types of people, how they think and therefore
why they might say the things they do.

nd it is of course also a wonderful way to peddle
pseudo-psychology

For you to say such authoritatively you would have to be in a position
to counter all the evidence supporting that brain lateralisation does
exist (and it does).

- or cast aspersions.

If the cap fits?


[1] though I must say I thought calling the corpus callosum a "point" a
bit like saying there's only a few dozen lines for calls across the Atlantic

A good example of a 'left brainer' / literal interpretation on my
very simple yet accurate statement. eg. If you look at the comparative
land masses of the UK and the USA and then the size of ALL the cables
between them, they wouldn't even register on that scale.

[2] : eg

http://journals.plos.org/plosone/art...l.pone.0071275

"we demonstrate that ...do not result in a subject-specific global brain
lateralization difference that favors one network over the other (i.e.
left-brained or right-brained).

Yet different people demonstrate different characteristics that seem
to fall into specific groupings? Have you not noticed a link between
those who do and don't understand the topic of this thread and their
position on Brexit for example? Could it be that someone willing to
completely ignore the feelings of between 1/2 and 2/3rds of the
electorate might consider others differently to someone who wouldn't?


https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3743825/

"Yet our analyses suggest that an individual brain is not “left-brained”
or “right-brained” as a global property, but that asymmetric
lateralization is a property of individual nodes or local subnetworks,

Yup?

and that different aspects of the left-dominant network and
right-dominant network may show relatively greater or lesser
lateralization within an individual. "

Bingo.

Sorry, what that supposed to disprove my basic concept Robin? ;-)

OK, try this. Do you feel that women are generally more empathetic
than men (and if they are, why that might be)?

If you do then you have already accepted that people can be different
and based on specific criteria (re EQ in this context) and probably on
a testable (and even measurable, MRI etc) scale.

So, if you have a stroke in the left side of your brain, why are you
statically more likely to have problems with speech than people who
have a stroke in the right hemisphere?

If both hemispheres (typically) dealt with the exact same things at
the same level why wouldn't it be 50:50?

Cheers, T i m

Tim Streater wrote:

Andy Burns wrote:

So are saying the circumference remains constant, hence the rpm
remains constant, hence iTPMS cannot work?

The steel cords may stretch a little, but that's all. Without that, the
circumference *must* stay constant.

The steel belts aren't parallel to the circumference, they're on a low
angle diagonally, so they can bunch-up or space-out with the distortion
of the tyre as it revolves, so the change in circumference can be more
than just you'd get by stretching them, though it still only needs to be
small to be measurable.

On Mon, 25 Jun 2018 16:16:44 +0100, Tim Streater
wrote:

In article , Andy Burns
wrote:

Tim Streater wrote:

One revolution of the wheel has to equal one passage of the tire's
circumference along the road (since the tire does not slip around the
rim and assuming no slip on the road). How could it be otherwise?

Talk of "effective radius" is not relevant.

So are saying the circumference remains constant, hence the rpm remains
constant, hence iTPMS cannot work?

The steel cords may stretch a little, but that's all.

They don't stretch, they *move*, along with the rubber.

Without that, the
circumference *must* stay constant.

What's that ... is the penny slowly dropping? ;-)

Cheers, T i m

In article ,
Tim Streater wrote:
OK. But that's what what has been being argued about at least in this
portion of the thread. People keep talking about the centre of the
wheel being closer to the road, which it is, and taking the centre-road
distance as a radius and computing a new circumference based on that,
which would be considerably more than 1% different from that for an
inflated tire.

Which is what matters when computing the speed of the wheel with a flat
tyre against one with a fully inflated tyre, or the figures for that.

--
*Age is a very high price to pay for maturity.

Dave Plowman London SW
To e-mail, change noise into sound.

On 24/06/18 08:03, Richard wrote:
On 23/06/18 17:01, The Natural Philosopher wrote:

No.
Since no wheel is circular using radious as a concept is plain wrong.
At best you can calcualate a '*radius it would be if it were round*,'
from the actual circumference.

The use of radius is completely right.
The circumference doesn't change. The centre of the instantaneous circle
moves closer to the radius.
The tyre is a three dimensional structure and this debate is being
conducted in a two dimensional manner.


I hope no one ebver emp;loys you in an engineering capacity.

The use of radius is meaningless. The the tyre is not round.

Go and get a technical education




--
"It is an established fact to 97% confidence limits that left wing
conspirators see right wing conspiracies everywhere"

On 24/06/18 16:16, DerbyBorn wrote:
The hight of the axle is reduced - therefore the effective radius is
reduced and therefore its effective circumference. The part of the tire not
in contact with the ground is irrelevant.

Another benighted idiot.

Really catching em out tonight.


--
"It is an established fact to 97% confidence limits that left wing
conspirators see right wing conspiracies everywhere"

On 24/06/18 21:04, Andy Burns wrote:
wrote:

Everyone seems very fixed in their ideas about this

I think it all comes down to the distortion of the tyre and the reduced
length of the flat chord BA vs the arc BPA that would exist if it wasn't
loaded at all.

http://the-contact-patch.com/book/road/c2020-the-contact-patch#figure-ERr

the more heavily loaded, or the less pressure it's inflated with, the
greater z will be, and the smaller the effective rolling radius, reading
through to the end of that page gives chapter and verse formulae ...

In short the flatter the tyre, the smaller the effective radius and the
faster the wheel needs to rotate to keep up, which is what the sensors
detect.

No. The effective radious first of all is almost ********. But if you
mean te circumferenmce divided by 2 PI then that will only change with
pressure, as the belts strech, Not with loading.

Otherwise p[eole would be travvling 30% slower when their tyres were
flat, for the same speedo reading



--
Outside of a dog, a book is a man's best friend. Inside of a dog it's
too dark to read.

Groucho Marx

On 24/06/18 22:18, Jeff wrote:


And yet if you consider a solid wheel, no tyre, it is the distance
between the axle and the road that determines the rate at which
it rotates at the same speed of the car over the ground.

Yes.

So when
a wheel with tyre sees a reduction in the distance between the
axle and the road due to a lower pressure in the tyre, you get
the same change in the rotation rate of the wheel which is
easy to measure with the ABS sensor on that wheel.

No. Once yopu put a non circular tyre on, you vannot talk about radius.

What counts is the distance round whatever shape the tread is. Al;l of
that has to be in contact with the road during one wheel revolution
unelss the tyre slips on the rim




--
Outside of a dog, a book is a man's best friend. Inside of a dog it's
too dark to read.

Groucho Marx

"The Natural Philosopher" wrote in message
news
No. The effective radious first of all is almost ********. But if you mean
te circumferenmce divided by 2 PI then that will only change with
pressure, as the belts strech, Not with loading.

Otherwise p[eole would be travvling 30% slower when their tyres were flat,
for the same speedo reading

They *will* be travelling slower - you've got that right. But not by
anywhere near as much as 30%.

On 25/06/18 06:50, Jeff wrote:


"Tjoepstil" wrote in message
news
On 24/06/18 22:18, Jeff wrote:
So when
a wheel with tyre sees a reduction in the distance between the
axle and the road due to a lower pressure in the tyre, you get
the same change in the rotation rate of the wheel which is
easy to measure with the ABS sensor on that wheel.

No, you don't.

Yes you do, as you should be able to see with a rim with no tyre at all.
As the rim diameter changes, the rotation rate will obviously change.

Thats becausd in that case the wehel is in fact round. Ther is a perfect
relatinship between circumgerencve and radious


Once iuy has a non round tyre on, your assumptions are invalid.


a tyre and wheel is not a sun and planet reduction gear,

It is a rack and pinion tho.

the tyre is not
rotating relative to the wheel,

Correct.

ergo every revolution of the wheel one
circumference of tyre must move along the road.

Yes, but it is the distance between the axle and the road
that determines the rotation rate.

No it isn't.

it is NOT a sun and planet gear. It is a squashy tyre on a wheel

https://www.youtube.com/watch?v=XNy4sdDJg2o

Look at the video 8:45 in and see what YOU are describing happening.


If you think thats how a flat tyre behaves god help you.


The ABS sensors do not detectÂ* a massive change in radius, but a small
change in circumference due to the tread shrinking very slightly.

They actually detect the substantial change in the rotation rate
the is due to the substantial change in the distance between the
axle and the road.

There are no substantial changes. Ther is a very small change due to
elsatyicity of the tread belt.

You know this is true otherwise speedos would
be massively variable with tyre pressure and wheel loading
They are not.



--
All political activity makes complete sense once the proposition that
all government is basically a self-legalising protection racket, is
fully understood.

On 25/06/18 09:47, Jeff wrote:


"Chris Hogg" wrote in message
...
On Mon, 25 Jun 2018 15:50:06 +1000, "Jeff" wrote:



Yes, but it is the distance between the axle and the road
that determines the rotation rate.

If the length of the perimeter of the tyre is say 1.5 metres, and the
vehicle is travelling at 150 km/hr, that means the tyre rotates 100000
times per hour, or 1666.6 rpm, assuming no slippage between tyre and
road or tyre and rim. There's no getting around that, and there's no
mention of state of inflation, shape of the tyre or axle to road
distance.

Yes, but it is the distance between the axle and the road
that determines the rotation rate.


No it is not.


--
"And if the blind lead the blind, both shall fall into the ditch".

Gospel of St. Mathew 15:14

On 25/06/18 09:57, Tim Lamb wrote:
In message , Jeff
writes


"Chris Hogg" wrote in message
...
On Mon, 25 Jun 2018 15:50:06 +1000, "Jeff" wrote:



Yes, but it is the distance between the axle and the road
that determines the rotation rate.

If the length of the perimeter of the tyre is say 1.5 metres, and the
vehicle is travelling at 150 km/hr, that means the tyre rotates 100000
times per hour, or 1666.6 rpm, assuming no slippage between tyre and
road or tyre and rim. There's no getting around that, and there's no
mention of state of inflation, shape of the tyre or axle to road
distance.

Yes, but it is the distance between the axle and the road
that determines the rotation rate.

Why?

Long time since 'O' level maths but I suspect the relationship between
the radius and the perimeter only works for a perfect circle.

Go to the top of the class.

What is the radius of an egg?




--
"And if the blind lead the blind, both shall fall into the ditch".

Gospel of St. Mathew 15:14

On 25/06/18 10:02, Huge wrote:
On 2018-06-25, Tim Lamb wrote:
In message , Jeff
writes


"Chris Hogg" wrote in message
...
On Mon, 25 Jun 2018 15:50:06 +1000, "Jeff" wrote:



Yes, but it is the distance between the axle and the road
that determines the rotation rate.

If the length of the perimeter of the tyre is say 1.5 metres, and the
vehicle is travelling at 150 km/hr, that means the tyre rotates 100000
times per hour, or 1666.6 rpm, assuming no slippage between tyre and
road or tyre and rim - There's no getting around that, and there's no
mention of state of inflation, shape of the tyre or axle to road
distance.

Yes, but it is the distance between the axle and the road
that determines the rotation rate.

Why?

Long time since 'O' level maths but I suspect the relationship between
the radius and the perimeter only works for a perfect circle.

I'll type this slowly for the hard of thinking.

The - Bits - Of - The - Tyre - Not - In - Contact - With - The - Road - Are -
Irrelevant. The - Only - Thing - That - Matters - Is - The - Diameter - Of -
The - Circle - Whose - Radius - Is - The - Distance - From - The - Axle - To.
The - Road.

I'll type this slowly for the hard of thinking.

The - Bits - Of - The - Tyre - Not - In - Contact - With - The - Road -
Are - Irrelevant. The - Only - Thing - That - Matters - Is - The -
Circumference-of-The-Non-Round-Tyre


--
"And if the blind lead the blind, both shall fall into the ditch".

Gospel of St. Mathew 15:14

"The Natural Philosopher" wrote in message
news
On 24/06/18 22:18, Jeff wrote:


And yet if you consider a solid wheel, no tyre, it is the distance
between the axle and the road that determines the rate at which
it rotates at the same speed of the car over the ground.

Yes.

So when
a wheel with tyre sees a reduction in the distance between the
axle and the road due to a lower pressure in the tyre, you get
the same change in the rotation rate of the wheel which is
easy to measure with the ABS sensor on that wheel.

No. Once yopu put a non circular tyre on, you vannot talk about radius.

What counts is the distance round whatever shape the tread is. Al;l of
that has to be in contact with the road during one wheel revolution unelss
the tyre slips on the rim

But if you were to label part of the tread with a line continuing radially
up the sidewall to the centre, that line would not remain a straight line;
it would curve one way as the labelled part approaches the road surface and
then the other way as it leaves it; this happens because the plies of the
steel belt move towards or away from each other as the tyre rotates. Not by
a noticeable amount; probably by an amount that is hard even to measure. The
tyre is no longer a perfect circle but a circle with a flat on the side
which is contact with the road at this precise instant. The distortion of
the sidewalls, both rotationally and as the bulge "travels" around the tyre
as the tyre rotates, is the reason that tyres get hot. The lower the
pressure, the more distortion and the more heating - to a point that the
tyre softens, melts and bursts.

On 25/06/18 10:48, Huge wrote:
In article ,
Tjoepstil wrote:
The ABS sensors do not detect a massive change in radius, but a small
change in circumference [...]

Ahh, so having a puncture causes the local space-time to become
non-Euclidian?

No, it doesn't.

How does that work?

I think Huge, you are probably too stupid to understand






--
"And if the blind lead the blind, both shall fall into the ditch".

Gospel of St. Mathew 15:14

On Mon, 25 Jun 2018 18:06:17 +0100, The Natural Philosopher
wrote:

snip

But if you
mean te circumferenmce divided by 2 PI then that will only change with
pressure, as the belts strech, Not with loading

Nope, also changes *because* of loading.

Otherwise p[eole would be travvling 30% slower when their tyres were
flat,

That would be advised, or possibly 100% slower!

for the same speedo reading

Well, probably not 30% but slower for sure.

Higher pressures will (also 'of course') change the *profile* of the
tyre (as can be seen by the tyre wear) and so the effective
circumference (and the actual (unloaded) circumference).

Not because of any steel belts *stretching* but because the tyre
changes shape (from wide and small to narrow and tall) ... hey, we
could call it 'pantographing'. ;-)

The outcome is similar to a racing motorbike where when the bike is
upright the driven wheel is maximum diameter but when leant over the
diameter changes (smaller) and to the revs would go up for the same
road speed. Same tyre, different results under different
circumstances.

I wonder if Turnip will ever get it and how he will get out of the
position he is currently in? Should be fun ... ;-)

Cheers, T i m

On 25/06/18 10:49, Huge wrote:
On 2018-06-25, Dave Plowman (News) wrote:
In article ,
Huge wrote:
I'll type this slowly for the hard of thinking.

The - Bits - Of - The - Tyre - Not - In - Contact - With - The - Road -
Are - Irrelevant. The - Only - Thing - That - Matters - Is - The -
Diameter - Of - The - Circle - Whose - Radius - Is - The - Distance -
From - The - Axle - To. The - Road.

You should have used caps, Huge. For those whose physics are still at
kindergarten level.

If they'll let me know where they are, I could go round (!) and try and
pummel it into their heads?


Well Huge, I am afraid you are the one at kindergarten level

I guess it goes with remaoning.

What I am saying is 100% correct and is borne out by tshe papers on the
subject and by the you tube video I linked to.


--
Renewable energy: Expensive solutions that don't work to a problem that
doesn't exist instituted by self legalising protection rackets that
don't protect, masquerading as public servants who don't serve the public.

On 25/06/18 10:50, Andy Burns wrote:
Dave Plowman wrote:

Huge wrote:

The - Bits - Of - The - Tyre - Not - In - Contact - With - The - Road -
Are - Irrelevant. The - Only - Thing - That - Matters - Is - The -
Diameter - Of - The - Circle - Whose - Radius - Is - The - Distance -
From - The - Axle - To. The - Road.

You should have used caps, Huge. For those whose physics are still at
kindergarten level.

Except there isn't a single distance from the centre of the axle to all
parts of the tyre in contact with the road ... the average distance
perhaps?
Even that doesn't work.

Huges simple minded O level fizzix cant cope with the reality of an
elastically coupled non-circular tyre attached in a non slip fashion to
a wheel.

This is the sort of thinking that creates climate Beleivers - people who
THINK they know a little bit of science ....

--
In a Time of Universal Deceit, Telling the Truth Is a Revolutionary Act.

- George Orwell

On 25/06/18 10:58, Huge wrote:
On 2018-06-25, Andy Burns wrote:
Dave Plowman wrote:

Huge wrote:

The - Bits - Of - The - Tyre - Not - In - Contact - With - The - Road -
Are - Irrelevant. The - Only - Thing - That - Matters - Is - The -
Diameter - Of - The - Circle - Whose - Radius - Is - The - Distance -
From - The - Axle - To. The - Road.

You should have used caps, Huge. For those whose physics are still at
kindergarten level.

Except there isn't a single distance from the centre of the axle to all
parts of the tyre in contact with the road ... the average distance perhaps?

Oh, FFS. This is really, really simple. Why are you all making it so
complicated? (It's the *shortest* distance, obviously. Just draw a bloody
diagram.)


Because it is not simple. Only you are simple. It is in fact fiendishly
complicated. And the short cut is to forget radius and think only of
circumgference If you think in terms of radius you will get it all wrong

Because the rim of the wheel is moving slower than you think, because
the tyre is flexing as it goes round.





--
In a Time of Universal Deceit, Telling the Truth Is a Revolutionary Act.

- George Orwell