NY wrote

I forgot to say that the previous car, the Golf, I used daily for more
than 45 years and only stopped using it when I had stupidly not
bothered to fix the known leaking windscreen and it eventually
rusted the floor and I couldnt be arsed to cut that out and replace
it.

That is a fantastic life for a car that is used every day.

And it required very little in the way of repairs in that time, just
an alternator regulator, distributor thing and an indicator relay.

And a petrol hose.

Only failure on the Getz was the original battery, real
failure, not the usual just wearing out, in now 12 years.

The distributor arm was almost certainly due to me choosing to
remove it to prevent theft of the car when I was away from home
without taking the car. And the car never spent any time in the
garage or carport either, because I never got around to building one.

My cars have generally had the normal wear and tyre things (brake
pads/discs, tyres, cambelt (and water pump*) at recommended mileage) that
you would expect. My previous Peugeot had to have a new "fanbelt" and that
replacement one lasted only a few thousand miles before it failed. On
closer inspection, it was found that one of the pulleys had warped,
*causing* the second (and probably the first) belt to fail. Sadly garage
(the local one in my village) denied liablility, so I had to pay for both
belts and (more importantly) the labour to fit them.

My present Pug had a failed clutch actuator mechanism (**) - failed
in-gear as I was setting off at the head of a queue of traffic at lights,
so without the ability to disengage the clutch, the car was stuck in gear
and I was stuck blocking the junction. Embarrassing. And this car has had
various problems with its anti-pollution system - extra complexity leads
to extra failure points. A new diesel particulate filter and a new cat (at
the same time) are not nice bills to have to pay for :-(

Still, it's going strong now and is worth a lot more to me as a car than
its resale value.

Yeah, I've always ignored resale value and have bought the last 3 new.

That's a standard symptom of clutch wear.

Sure, I meant I havent seen that level of wear in any car of mine.

I suppose it you don't do much stop-start driving or having to hill-start
on steep hills, the clutch wear will be less than mine.

The difference appears to be how we drive, I dont ride the clutch, ever.

There is a notorious 1:3 hill near where I used to live and twice I've had
to stop and restart when the car in front of me has got into
difficulties. Setting off is "interesting" on a 1:3 hill: you need good
handbrake/clutch/accelerator coordination. I tried not to think about the
wear that it would be putting on the clutch.

That doesnt happen often enough to wear the clutch.

Ah. I remember my first two fuel-injected cars in the 1990s had a big
rotary variable resistor under the bonnet, roughly where a carburettor
used to be, operated by a Bowden cable. I've just checked my present car
and I can't see any sign of something like that so they've stopped doing
it that way now.

Yeah, very crude approach to morphing the design IMO. What brands ?

VW Gold Mark III (1992), Peugeot 306 with the non-HDi engine (1995).

(*) Since the water pump is driven from the cambelt, the garage advises
that while they have dismantled everything to replace the cambelt, they
should replace the water pump even if it seems to be OK, since the cost of
the pump is much less than the labour to replace it later on - kill two
birds with one stone.

(**) Functionally equivalent to the clutch cable snapping. I think the
pedal connects by cable to an intermediate hydraulic actuator which in
turn moves the clutch plate, rather than the cable being directly
connected.

Tim Streater wrote:

The problem we have on this ng is too many unimaginative dimwits

Yeah, better that we have some whose imagination is so powerful, they
can dream up ways to say that a device that plainly does work, cannot
possibly work ...

"Rod Speed" wrote in message
...
I suppose it you don't do much stop-start driving or having to hill-start
on steep hills, the clutch wear will be less than mine.

The difference appears to be how we drive, I dont ride the clutch, ever.

Depends what exactly "ride the clutch" means - I've never known precisely. I
presume it means letting the clutch slip any more than it has to in order to
do its job. Every time you set off from rest, the clutch will slip - that's
the whole purpose of a clutch, to cushion setting off at a minimum but
non-zero engine speed which, in the lowest gear, equates to a few mph, which
you don't want to present, in an instant, to the driving wheels. The amount
of slippage depends on the effective weight of the vehicle (ie mass times
sin(gradient angle)) and the engine speed. You try to minimise this by a)
keeping the engine revs as low as you can without stalling, b) letting the
clutch up as fast as possible without jerking the car so it spends a minimum
time slipping, and c) not applying much power until the clutch is fully
engaged.

Other gearchanges *theoretically* cause no wear if you manage to match the
engine speed to the road speed in the new gear. I'm probably not *too* bad
at getting it close, but I'm not perfect - my "good" to "cocked-up"
gearchange ratio is high but not 100% ;-) I certainly don't do what one
driver did who gave me a lift. She took her foot right off the accelerator
at each and every gear change, changed to the new gear and then either let
the clutch up on the idling engine (which caused a sudden retardation) or
else revved the engine to far too high a speed before letting the clutch up
(which caused a sudden jolt forwards). I dread to think what effect it was
having on her clutch. When she apologised and said "help!" after a
*particularly* bad jolt, I very tactfully suggested that it might be useful
if she tried at least to maintain the same engine revs, or else perhaps let
the engine note drop a little bit if she was changing up or let it rise
slightly if she was changing down. Admittedly it's not as easy as in a
modern car with a rev counter, but by no means impossible even if you've
only got the engine note to go by. Had she been a newly-qualified learner, I
could have understood it, though I'd have hoped her instructor might have
helped her perfect the black art of gearchanges, but she was older than me
and had been driving longer than I had. I earned a good few kudos points
when she said "show me" and I drove a little way, in a "strange car" without
any of the lurches that she thought were due to her car being clapped out.
It didn't help that she was fairly short and had small feet, so she had to
lift her heel off the floor every time she let the clutch pedal up, which
makes fine control a *lot* more difficult if you can't pivot on your heel.

Whenever I go to the supermarket and park in the car park, I hear the
tell-tale sound of a driver (usually elderly) who revs up to about 2000 rpm
and then lets the clutch just kiss the flywheel as he reverses out. The
slippage and the wear and heat don't bear thinking about. I'm spoiled in a
diesel car that the engine will pull when it's barely idling, so I can set
off with my foot off the throttle, just giving the car a little nudge and
then disengaging (fully!) as I let the car roll in or out of the parking
space, without any need for a racing engine. It only requires you to let the
clutch in slightly further than you intended when you're in first gear at
2000 rpm, and the car will lurch into the car or brick wall ahead.

NY wrote
Rod Speed wrote

I suppose it you don't do much stop-start driving or having to
hill-start on steep hills, the clutch wear will be less than mine.

The difference appears to be how we drive, I dont ride the clutch, ever.

Depends what exactly "ride the clutch" means - I've never known precisely.

Have your foot on the clutch with the clutch itself slipping so you dont
either have the clutch fully engaged, not slipping, or fully disengaged.

I presume it means letting the clutch slip any more than it has to in
order to do its job.

Yes.

Every time you set off from rest, the clutch will slip - that's the whole
purpose of a clutch, to cushion setting off at a minimum but non-zero
engine speed which, in the lowest gear, equates to a few mph, which you
don't want to present, in an instant, to the driving wheels.

Yes, but doing that clearly didnt see my Golf need a new one in
more than 45 years of daily driving, or even see the grab point
change as far as the pedal position changing is concerned either.

The amount of slippage depends on the effective weight of the vehicle (ie
mass times sin(gradient angle)) and the engine speed. You try to minimise
this by a) keeping the engine revs as low as you can without stalling,

I dont.

b) letting the clutch up as fast as possible without jerking the car so it
spends a minimum time slipping, and c) not applying much power until the
clutch is fully engaged.

I dont do that either.

Other gearchanges *theoretically* cause no wear if you manage to match the
engine speed to the road speed in the new gear. I'm probably not *too* bad
at getting it close, but I'm not perfect - my "good" to "cocked-up"
gearchange ratio is high but not 100% ;-)

Cant remember the last time I ever stuffed that up.
And I do change gears around most corners.

I certainly don't do what one driver did who gave me a lift. She took her
foot right off the accelerator at each and every gear change, changed to
the new gear and then either let the clutch up on the idling engine (which
caused a sudden retardation) or else revved the engine to far too high a
speed before letting the clutch up (which caused a sudden jolt forwards).
I dread to think what effect it was having on her clutch. When she
apologised and said "help!" after a *particularly* bad jolt, I very
tactfully suggested that it might be useful if she tried at least to
maintain the same engine revs, or else perhaps let the engine note drop a
little bit if she was changing up or let it rise slightly if she was
changing down. Admittedly it's not as easy as in a modern car with a rev
counter, but by no means impossible even if you've only got the engine
note to go by

I never use the rev counter when changing gears.

Had she been a newly-qualified learner, I could have understood it, though
I'd have hoped her instructor might have helped her perfect the black art
of gearchanges, but she was older than me and had been driving longer than
I had. I earned a good few kudos points when she said "show me" and I
drove a little way, in a "strange car" without any of the lurches that she
thought were due to her car being clapped out. It didn't help that she was
fairly short and had small feet, so she had to lift her heel off the floor
every time she let the clutch pedal up, which makes fine control a *lot*
more difficult if you can't pivot on your heel.

Whenever I go to the supermarket and park in the car park, I hear the
tell-tale sound of a driver (usually elderly) who revs up to about 2000
rpm and then lets the clutch just kiss the flywheel as he reverses out.
The slippage and the wear and heat don't bear thinking about. I'm spoiled
in a diesel car that the engine will pull when it's barely idling, so I
can set off with my foot off the throttle, just giving the car a little
nudge and then disengaging (fully!) as I let the car roll in or out of the
parking space, without any need for a racing engine. It only requires you
to let the clutch in slightly further than you intended when you're in
first gear at 2000 rpm, and the car will lurch into the car or brick wall
ahead.

Bugger all carparks have the cars parking up to a brick wall.

On Thu, 28 Jun 2018 05:38:24 +1000, cantankerous geezer Rot Speed blabbered,
again:

FLUSH most of the never-ending idiotic drivel

nudge and then disengaging (fully!) as I let the car roll in or out of the
parking space, without any need for a racing engine. It only requires you
to let the clutch in slightly further than you intended when you're in
first gear at 2000 rpm, and the car will lurch into the car or brick wall
ahead.

Bugger all carparks have the cars parking up to a brick wall.

Looks like you found yet another idiot who is too stupid to see through you,
Rot! You should stick by him at all costs! LOL

On Wed, 27 Jun 2018 19:50:37 +0100, Andy Burns
wrote:

Tim Streater wrote:

The problem we have on this ng is too many unimaginative dimwits

Yeah, better that we have some whose imagination is so powerful, they
can dream up ways to say that a device that plainly does work, cannot
possibly work ...

It seems the self confessed 'know it all's' are tripping over
themselves to disprove reality on this one Andy. ;-)

They all seem so very keen to deny the *facts* put forward by the
experts in the field (and those of us who can understand them) but
completely fail to come up with an alternative explanation themselves
(well, not that a 5yr old couldn't see though, like Streaters last
droolings). ;-)

Cheers, T i m

On Wed, 27 Jun 2018 18:46:43 +0100
"NY" wrote:

My present Pug had a failed clutch actuator mechanism (**) - failed
in-gear as I was setting off at the head of a queue of traffic at
lights, so without the ability to disengage the clutch, the car was
stuck in gear and I was stuck blocking the junction.

Why could you not just knock it out of gear?

"Rod Speed" wrote in message
...
Yes, but doing that clearly didnt see my Golf need a new one in
more than 45 years of daily driving, or even see the grab point
change as far as the pedal position changing is concerned either.

I won't say outright that I simply do not believe you when you say that you
drove a Golf for 45 years and in that time the bite point didn't change,
even though auto-adjusting clutch mechanisms were probably less common in a
car of the age of a Mark I Golf from 1973. But I am very surprised.

The amount of slippage depends on the effective weight of the vehicle (ie
mass times sin(gradient angle)) and the engine speed. You try to minimise
this by a) keeping the engine revs as low as you can without stalling,

I dont.

So you don't minimise the engine revs...

b) letting the clutch up as fast as possible without jerking the car so
it spends a minimum time slipping, and c) not applying much power until
the clutch is fully engaged.

I dont do that either.

.... And you don't minimise the time that the clutch is slipping (neither
fully disengaged nor fully engaged).

And yet you've had a clutch last 45 years, even without taking those
precautions?

Other gearchanges *theoretically* cause no wear if you manage to match
the engine speed to the road speed in the new gear. I'm probably not
*too* bad at getting it close, but I'm not perfect - my "good" to
"cocked-up" gearchange ratio is high but not 100% ;-)

Cant remember the last time I ever stuffed that up.

But I bet (unless you are superhuman) you won't be as good at matching
engine to road speed in new gear, accurately and consistently, as a DSG
gearbox will be. I only claim to be good; I don't claim to be perfect.

Bugger all carparks have the cars parking up to a brick wall.

Now that really is a daft statement - so easily disproved. Most small
non-supermarket car parks have a row of cars parking against the wall of a
building and maybe some against a boundary wall between the car park and a
pavement. Most multi-storey car parks have some cars parking against the
outside wall - OK, it's probably concrete rather than brick, but let's not
be picky.

On Wed, 27 Jun 2018 19:36:57 +0100, Tim Streater
wrote:

snip

Imagine this:

This could be interesting ... the fine arts dropout trying to explain
mechanics ...

take some white paint and paint a line from within the
wheel's nuts out to the edge of the wheel,

Here we go ... we had to get back to painting didn't we ...

onto the inflated tire and
out to where the tread starts. Repeat at angles of say 30 deg so you
have 12 segments all the way round the wheel.

Yes ...

Now rotate the wheel once. All the lines will stay intact

No!?

and the car
will move along a distance equal to the circumference.

*Wrong!*. It will move forward the distance of the *effective
circumference*.

Now it's been
said here that the steel belts are not quite circumferential,

They are not *at all* 'circumferential and in fact criss cross at
nearly 90 Degrees to each other.

so if we
now deflate the tire, its circumference will reduce a small amount.

No it won't. The 'effective circumference' will though (as the only
time the two are equal is where there is no load on the tyre at all).

I
am not considering that since arguments here seem to focus on other
reasons for reducing the circumference.

Go on ...

If we now again rotate the wheel once, then assuming no slip along the
rim between the wheel and the tire,

Why would you even have to write that? When was the last time you were
aware of any such slip, outside of a trials bike and they have rim
locks to prevent that very thing?

OOI, how many tyres of any type have you ever dismounted in your life?

after one turn the lines on the
wheel/tire will be intact and the car has moved the same distance.

The same distance as the first time based on the effective
circumference yes.

Now, what *might* happen, is that because the side wall can flex, the
painted lines will spiral a small amount on the tire wall and the first
turn of the wheel doesn't move the car as far as it should.

That would be transitional so irrelevant to any of this.

But the
spiralling will cease to have a further effect once the tire wall has
spiralled as much as it can.

Duh.

After that, the car will move the same
distance for one wheel turn, flat or inflated.

Yes, and 'winding up' of the sidewall is transitory in any case
dimwit.

You can also imagine that if you could get hold of a tire of the same
overall diameter but to go on a much smaller wheel, that the spiralling
effect when flat would be much more pronounced as the tire wall would
be bigger. But, once spiralled up, one turn of the wheel would send the
car the same distance, flat or not.

WTF are you drooling on about now!?

The problem we have on this ng is too many unimaginative dimwits unable
to think clearly about the problem.

Bwhahahaha ... go back to painting lines on yer car wheels you fine
artist! ;-)

Why are you and your kind in so much denial re what are obviously the
facts and why do you continue to put up fascicle and bogus BS in the
way of some alternative explanation?

It's exactly the same thing re Brexit where you seem to have this
special insight but it fails every RW test anyone throws at it. ;-(


Cheers, T i m

NY wrote
Rod Speed wrote

The amount of slippage depends on the effective weight of the vehicle
(ie mass times sin(gradient angle)) and the engine speed. You try to
minimise this by a) keeping the engine revs as low as you can without
stalling,

I dont.

So you don't minimise the engine revs...

b) letting the clutch up as fast as possible without jerking the car so
it spends a minimum time slipping, and c) not applying much power until
the clutch is fully engaged.

I dont do that either.

... And you don't minimise the time that the clutch is slipping (neither
fully disengaged nor fully engaged).

I do in the sense that I dont ever ride the clutch
even in slow moving traffic or that other situation
where you said you do that. Presumably that is
the situation, riding the clutch, where you get
a lot more wear on the clutch, because that
goes on for a lot longer at a time than when
changing gears or starting off from stationary and
so the clutch gets a lot hotter and wears more.

And yet you've had a clutch last 45 years, even without taking those
precautions?

Yep.

Other gearchanges *theoretically* cause no wear if you manage to match
the engine speed to the road speed in the new gear. I'm probably not
*too* bad at getting it close, but I'm not perfect - my "good" to
"cocked-up" gearchange ratio is high but not 100% ;-)

Cant remember the last time I ever stuffed that up.

But I bet (unless you are superhuman) you won't be as good at matching
engine to road speed in new gear, accurately and consistently, as a DSG
gearbox will be.

Irrelevant to what needs to be done with a manual gearbox
to still get the clutch last fine for 45 years of daily driving.

Bugger all carparks have the cars parking up to a brick wall.

Now that really is a daft statement - so easily disproved.

We'll see...

Most small non-supermarket car parks have a row of cars parking against
the wall of a building

And plenty have a footpath between the cars and the building.

and maybe some against a boundary wall between the car park and a
pavement.

Bugger all do that and plenty like my Aldi have concrete thing
on the ground before the path to stop cars overhanging the path.

Most multi-storey car parks have some cars parking against the outside
wall -

And those often have a concrete thing on the ground
that stops the cars damaging the wall if they even have
a wall at all on the outside of that carpark.

"Rob Morley" wrote in message
news:20180627224721.070920bf@Mars...
On Wed, 27 Jun 2018 18:46:43 +0100
"NY" wrote:

My present Pug had a failed clutch actuator mechanism (**) - failed
in-gear as I was setting off at the head of a queue of traffic at
lights, so without the ability to disengage the clutch, the car was
stuck in gear and I was stuck blocking the junction.

Why could you not just knock it out of gear?

With all the cars I've ever owned, if you happen to stall the engine in gear
with the clutch up, the gear lever jams and is only released if you press
the clutch.

On 27/06/2018 22:11, T i m wrote:
On Wed, 27 Jun 2018 19:50:37 +0100, Andy Burns
wrote:

Tim Streater wrote:

The problem we have on this ng is too many unimaginative dimwits

Yeah, better that we have some whose imagination is so powerful, they
can dream up ways to say that a device that plainly does work, cannot
possibly work ...

It seems the self confessed 'know it all's' are tripping over
themselves to disprove reality on this one Andy. ;-)

They all seem so very keen to deny the *facts* put forward by the
experts in the field (and those of us who can understand them) but
completely fail to come up with an alternative explanation themselves
(well, not that a 5yr old couldn't see though, like Streaters last
droolings). ;-)

Cheers, T i m


I can't see why people can't see that a tyre has knobbly bits on them.
these move so the actual circumference changes when these bits, also
known as the tread, moves. Then there are the flexible side walls.

On 27/06/18 19:50, Andy Burns wrote:
Tim Streater wrote:

The problem we have on this ng is too many unimaginative dimwits

Yeah, better that we have some whose imagination is so powerful, they
can dream up ways to say that a device that plainly does work, cannot
possibly work ...

That was never claimed.

Only the means by which it worked.

Dont be such a 'flat tyre denier'


--
"Socialist governments traditionally do make a financial mess. They
always run out of other people's money. It's quite a characteristic of them"

Margaret Thatcher

On 27/06/18 19:36, Tim Streater wrote:
You can also imagine that if you could get hold of a tire of the same
overall diameter but to go on a much smaller wheel, that the spiralling
effect when flat would be much more pronounced as the tire wall would
be bigger. But, once spiralled up, one turn

I've been thinking about this a lot trying to make it simple enough for
even a remoaner to understand.

The fallacy is in Huge's basic premise that because the axle is a given
height above te ground, that represents the 'effective/rolling radius*'
of the tyre.

It does not.

The 'effective/rolling radius' is /always/ the circumference divided by
2 PI.

How can this be? Quite simply because the tyre is attached to the wheel
all round, and the tyre is dragged along by the sidewall such that the
tread is moving faster (angular velocity) than the rim at the point of
'flatness'.

So Huge's assumption that the tyre tread speed is actually it's distance
from the axis of rotation, times the speed of rotation of the wheel, is
simply a mistake. It is in fact *greater*, at that point, and its the
sidewall flexure that takes up the strain, and the attachment of the
tyre at other points of the rim that creates that strain.

Should the wheel deflate completely, then the strain in the sidewall and
the friction between the tread and the rim as the two models
compete...leads to rapid separation of tread and wheel.

You then end up then with a wheel rim and tyre tread rotating at
completely different angular velocity. The triumph of 'Huge's model' is
to rip the tyre sidewall apart to allow that to happen.


If you follow F1 you can see this regularly - you end up with the
sidewall disintegrating and a more or less intact tread separating from
the car wheel entirely.


This leads to the conclusions that what affects wheel RPM - in a non
slip case - apart from car speed, is change in *circumference* alone,
and that will be a function of tyre tread elasticity, tyre pressure and
tyre RPM only, due to 'centrifugal force'.

Loading won't affect it at all.

And whoever dreamt up 'effective' or 'rolling' radius deserves to be
strapped to a centrifuge.

A little knowledge is a dangerous thing.

So is relying on 'experts' who are equally ignorant.

A lot of engineering is highly counter intuitive.


*and this is an utterly misleading term to start with and the cause of
most of the confusion.



--
The lifetime of any political organisation is about three years before
its been subverted by the people it tried to warn you about.

Anon.

On Thu, 28 Jun 2018 08:42:37 +0100, "dennis@home"
wrote:

snip

I can't see why people can't see that a tyre has knobbly bits on them.

I think even the thickest of them may know that but may not be able to
go from that to the concept the a tyre is a very dynamic thing.

these move so the actual circumference changes when these bits, also
known as the tread, moves.

I think it all takes too much of a leap of the imagination for people
who are very likely to be left brainers.

They will find it very difficult to accept something they don't or
can't understand, no matter how many people try to explain it to them
or the facts that it's working all around them.

Then there are the flexible side walls.

It's all down to the construction of the structure within the tyre and
how it does what it does.

Many people have seen a pantograph, even if they haven't consciously
considered what it does when it's working but if you were to imagine
the mechanism of a pop rivet gun, wrapped round on the flat into a
circle, then that's what a steel belted tyre construction is.

Where the flat of the tyre (cord) is on the road, the tread would be
flattened out and spread wider and when these things get bigger in one
dimension they *have* to get smaller in the other?

Hence, where the tyre sits flat on the road the carcase of the tyre
will have shrunk longitudinally and hence reducing the 'effective
circumference'.

Most of the rest of the tyre would still be 'normal' because unlike
the rivet gun, the steel belts are reasonably flexible (or we would
see the flat bit at the bottom spread round the entire tyre).

Cheers, T i m

On Thu, 28 Jun 2018 09:57:04 +1000, cantankerous geezer Rot Speed blabbered,
again:


Bugger all carparks have the cars parking up to a brick wall.

Now that really is a daft statement - so easily disproved.

We'll see...

No, we won't, you driveling senile moron!

Most small non-supermarket car parks have a row of cars parking against
the wall of a building

And plenty have a footpath between the cars and the building.

This senile Ozzie cretin is simply unbelievable ...but kinda entertaining!
LOL

--
Sqwertz to Rot Speed:
"This is just a hunch, but I'm betting you're kinda an argumentative
asshole.
MID:

"The Natural Philosopher" wrote in message
news
On 27/06/18 19:36, Tim Streater wrote:
You can also imagine that if you could get hold of a tire of the same
overall diameter but to go on a much smaller wheel, that the spiralling
effect when flat would be much more pronounced as the tire wall would
be bigger. But, once spiralled up, one turn

I've been thinking about this a lot trying to make it simple enough for
even a remoaner to understand.

The fallacy is in Huge's basic premise that because the axle is a given
height above te ground, that represents the 'effective/rolling radius*' of
the tyre.

It does not.

It does when considering the distance that determines the rotation rate of
the wheel.

The 'effective/rolling radius' is /always/ the circumference divided by 2
PI.

Not when it is the distance between the axle and the road that
determines the rotation rate of the wheel.

How can this be? Quite simply because the tyre is attached to the wheel
all round, and the tyre is dragged along by the sidewall such that the
tread is moving faster (angular velocity) than the rim at the point of
'flatness'.

So Huge's assumption that the tyre tread speed is actually it's distance
from the axis of rotation, times the speed of rotation of the wheel, is
simply a mistake. It is in fact *greater*, at that point, and its the
sidewall flexure that takes up the strain, and the attachment of the tyre
at other points of the rim that creates that strain.

Should the wheel deflate completely, then the strain in the sidewall and
the friction between the tread and the rim as the two models
compete...leads to rapid separation of tread and wheel.

You then end up then with a wheel rim and tyre tread rotating at
completely different angular velocity. The triumph of 'Huge's model' is to
rip the tyre sidewall apart to allow that to happen.


If you follow F1 you can see this regularly - you end up with the sidewall
disintegrating and a more or less intact tread separating from the car
wheel entirely.


This leads to the conclusions that what affects wheel RPM - in a non slip
case - apart from car speed, is change in *circumference* alone, and that
will be a function of tyre tread elasticity, tyre pressure and tyre RPM
only, due to 'centrifugal force'.

Loading won't affect it at all.

And whoever dreamt up 'effective' or 'rolling' radius deserves to be
strapped to a centrifuge.

A little knowledge is a dangerous thing.

So is relying on 'experts' who are equally ignorant.

But it is very easy to measure both a fully inflated tyre
and one that is say 20% under inflated and see if the
rotation rate of the wheel is in fact determined by the
distance between the axle and the road or the very
minimal change in the circumference of the tyre and
that must have been done when designing the ABS
system for detecting under inflated tyres.

A lot of engineering is highly counter intuitive.

Doesnt matter when it is so easy measure.

*and this is an utterly misleading term to start with and the cause of
most of the confusion.

On Thu, 28 Jun 2018 09:46:40 +0100, The Natural Philosopher
wrote:

On 27/06/18 19:36, Tim Streater wrote:
You can also imagine that if you could get hold of a tire of the same
overall diameter but to go on a much smaller wheel, that the spiralling
effect when flat would be much more pronounced as the tire wall would
be bigger. But, once spiralled up, one turn

I've been thinking about this a lot trying to make it simple enough for
even a remoaner to understand.

The only way you will be able to do that (Brexsh1tter) is by first
understanding it yourself.

The fallacy is in Huge's basic premise that because the axle is a given
height above te ground, that represents the 'effective/rolling radius*'
of the tyre.

There is such a thing but I'm not saying that it is any mechanically
measurable.

It does not.

The 'effective/rolling radius' is /always/ the circumference divided by
2 PI.

Nope. The effective rolling radius is the effective rolling
circumference divided by 2 Pi.

How can this be?

It can't so it isn't.

Quite simply

No such thing. The whole process of a tyre moving is far from 'quite
simple' (if it was, even you would understand it).

because the tyre is attached to the wheel
all round, and the tyre is dragged along by the sidewall such that the
tread is moving faster (angular velocity) than the rim at the point of
'flatness'.

So where is your 'the circumference is always the circumference' now?

So Huge's assumption that the tyre tread speed is actually it's distance
from the axis of rotation, times the speed of rotation of the wheel, is
simply a mistake.

It's nearer the truth than any waffle you have come up with so far.

It is in fact *greater*, at that point, and its the
sidewall flexure that takes up the strain, and the attachment of the
tyre at other points of the rim that creates that strain.

All distraction waffle. Where is your constant circumference in all
this now?

Should the wheel deflate completely, then the strain in the sidewall and
the friction between the tread and the rim as the two models
compete...leads to rapid separation of tread and wheel.

You got that be right at least but has nothing whatsoever to do with
this topic. The front of the car will also deform when you hit a wall.
shrug

You then end up then with a wheel rim and tyre tread rotating at
completely different angular velocity.

Nope, Unless the bead has separated from the rim, everything will
still be rotating at the same speed (as we have now jumped from low
pressure to no pressure and most of the previous rules go out the
window as the tyre isn't moving 'as designed'.

The triumph of 'Huge's model' is
to rip the tyre sidewall apart to allow that to happen.

Nope. Still very wrong.


If you follow F1 you can see this regularly - you end up with the
sidewall disintegrating and a more or less intact tread separating from
the car wheel entirely.

I love the way you announce such things so authoritively where it's
patently obvious to most (right brainers) that you are way out of your
depth.

The *reason* most F1 tyres disintegrate that way is because the
sidewalls have been weakened / damaged in some way, either because
they have been pushed too hard for too long or (and most commonly),
because they have made contact with another car, the barriers or
debris.


This leads to the conclusions that what affects wheel RPM - in a non
slip case - apart from car speed, is change in *circumference* alone,

What else can it be? What else is related to rpm and distance
traveled?

and that will be a function of tyre tread elasticity,

Correct (for this topic).

tyre pressure

See above.

and
tyre RPM only, due to 'centrifugal force'.

So, an iTPMS wouldn't trigger at high speed because centripetal force
was making the tyre expand and so rotate *slower* for the same mph?

Loading won't affect it at all.

Of course it will.

And whoever dreamt up 'effective' or 'rolling' radius deserves to be
strapped to a centrifuge.

Typical left brainer response to something they don't understand.
Everone else who does actually know are just 'talking heads' to be
ignored.

A little knowledge is a dangerous thing.

As you perfectly demonstrate here.

So is relying on 'experts' who are equally ignorant.

Bwhahahaha.

A lot of engineering is highly counter intuitive.

Obviously.


*and this is an utterly misleading term to start with and the cause of
most of the confusion.

To you, not those who actually understand what's going on.

So, once again you have attempted to disprove both what is going on
with millions of cars ITRW whilst not offering a counter argument to
actually explain what's going on.

I think the stress of being a fanatical Brexiteer (along with Streater
et al) has burnt what is left of your brain out ... that and / or
desperately trying to defend the indefensible. ;-(

Cheers, T i m

On Thu, 28 Jun 2018 19:24:48 +1000, "Jeff" wrote:

snip

So is relying on 'experts' who are equally ignorant.

But it is very easy to measure both a fully inflated tyre
and one that is say 20% under inflated and see if the
rotation rate of the wheel is in fact determined by the
distance between the axle and the road or the very
minimal change in the circumference of the tyre and
that must have been done when designing the ABS
system for detecting under inflated tyres.

The thing is one is a function of the other (cause and effect).

eg, If you have a solid wheel then the arbitrary circumference is the
same as the rolling circumference (so wouldn't work with an iTPMS
system). ;-)

Once a tyre can deflect under load and especially when it does so as
per of it's design, you no longer have a linear circumference (or even
a circumference in the true sense) but you do have something that
relates to the original circumference by some factor. The *exact* same
applies to the real radius (solid wheel) and an effective / loaded /
rolling radius when you don't have a real circumference.

Now, I haven't stated the RW relationship between the distance between
the axle and the ground on a loaded pneumatic tyre / wheel and the
'effective circumference' other than there is likely to be a link
between the two.

The key factor here is *how* does the speed of a deflating tyre change
for an iTPMS system to work (and they do work obviously). Now, we
don't need to define the situation by saying 'assuming no slip between
the tyre and the rim' as anyone who has tried to remove a tyre will
attest, nor do you have to state 'with no slip between the tyre and
the road' because if there was it would nearly be impossible to
predict anything. We certainly wouldn't need to mention anything about
the sidewall winding up because that will simply unwind again as the
torque (acceleration / braking) is removed.

So, we are down to *something* happening to effectively shorten the
effective circumference and about the only think logical (to any right
brainer that is) that at the point of the cord where the tyre flattens
out and the sidewall bulges where the tyre sits on the road, there is
a shortening of the tread length across this cord and hence a produce
a shorter 'effective rolling circumference'.

So, the left brainers deny this being even likely but without offering
any better solution themselves (and Turnip never will now of course,
not now he's backed himself into a very dark corner. Or he might, but
it will be that he has now come up with the answer all by himself).
;-)

Cheers, T i m

On 28/06/18 10:24, Jeff wrote:


"The Natural Philosopher" wrote in message
news
On 27/06/18 19:36, Tim Streater wrote:
You can also imagine that if you could get hold of a tire of the same
overall diameter but to go on a much smaller wheel, that the spiralling
effect when flat would be much more pronounced as the tire wall would
be bigger. But, once spiralled up, one turn

I've been thinking about this a lot trying to make it simple enough
for even a remoaner to understand.

The fallacy is in Huge's basic premise that because the axle is a
given height above te ground, that represents the 'effective/rolling
radius*' of the tyre.

It does not.

It does when considering the distance that determines the rotation rate
of the wheel.

The 'effective/rolling radius' is /always/ the circumference divided
by 2 PI.

Not when it is the distance between the axle and the road that
determines the rotation rate of the wheel.

How can this be? Quite simply because the tyre is attached to the
wheel all round, and the tyre is dragged along by the sidewall such
that the tread is moving faster (angular velocity) than the rim at the
point of 'flatness'.

So Huge's assumption that the tyre tread speed is actually it's
distance from the axis of rotation, times the speed of rotation of the
wheel, is simply a mistake. It is in fact *greater*, at that point,
and its the sidewall flexure that takes up the strain, and the
attachment of the tyre at other points of the rim that creates that
strain.

Should the wheel deflate completely, then the strain in the sidewall
and the friction between the tread and the rim as the two models
compete...leads to rapid separation of tread and wheel.

You then end up then with a wheel rim and tyre tread rotating at
completely different angular velocity. The triumph of 'Huge's model'
is to rip the tyre sidewall apart to allow that to happen.


If you follow F1 you can see this regularly - you end up with the
sidewall disintegrating and a more or less intact tread separating
from the car wheel entirely.


This leads to the conclusions that what affects wheel RPM -Â* in a non
slip case -Â* apart from car speed, is change in *circumference* alone,
and that will be a function of tyre tread elasticity, tyre pressure
and tyre RPM only, due to 'centrifugal force'.

Loading won't affect it at all.

And whoever dreamt up 'effective' or 'rolling' radius deserves to be
strapped to a centrifuge.

A little knowledge is a dangerous thing.

So is relying on 'experts' who are equally ignorant.

But it is very easy to measure both a fully inflated tyre
and one that is say 20% under inflated and see if the
rotation rate of the wheel is in fact determined by the
distance between the axle and the road or the very
minimal change in the circumference of the tyre and
that must have been done when designing the ABS
system for detecting under inflated tyres.

Indeed. I see that my efforts are watsed and you havent understood a
word I said, nor even looked at the video I posted way back where
someone did precusely this and showed that within the limits of te
technique, flattening te tyre made no measureable difference - ceraiunly
not as much as the 'loss of radius' would account for. Nor yet te p[aper
I likned to that showed taht te differemnce with 30% deflation was of
the order of a percent or so. WAY less than would be accounted for by
the 'loss of radius'



A lot of engineering is highly counter intuitive.

Doesnt matter when it is so easy measure.

Why don't you measure it then?

I see that other people have, and that confirms my thesis.

What I wouuld ask you is how a tyre, rotating at a differentent rate
from a wheel, so that its circumference does in fact get covered on the
ground by that rotaion, stays on the wheel without ripping the tread off?





--
No Apple devices were knowingly used in the preparation of this post.

"T i m" wrote in message
...
On Thu, 28 Jun 2018 19:24:48 +1000, "Jeff" wrote:

snip

So is relying on 'experts' who are equally ignorant.

But it is very easy to measure both a fully inflated tyre
and one that is say 20% under inflated and see if the
rotation rate of the wheel is in fact determined by the
distance between the axle and the road or the very
minimal change in the circumference of the tyre and
that must have been done when designing the ABS
system for detecting under inflated tyres.

The thing is one is a function of the other (cause and effect).

Yes, but the change in the circumference is much smaller
than the change in the distance between the axle and
the road with an under inflated tyre and it would be obvious
which is controlling the measured rotation rate of the wheel.

eg, If you have a solid wheel then the arbitrary circumference is the
same as the rolling circumference (so wouldn't work with an iTPMS
system). ;-)

Once a tyre can deflect under load and especially when it does so as
per of it's design, you no longer have a linear circumference (or even
a circumference in the true sense) but you do have something that
relates to the original circumference by some factor. The *exact* same
applies to the real radius (solid wheel) and an effective / loaded /
rolling radius when you don't have a real circumference.

Now, I haven't stated the RW relationship between the distance between
the axle and the ground on a loaded pneumatic tyre / wheel and the
'effective circumference' other than there is likely to be a link
between the two.

The key factor here is *how* does the speed of a deflating tyre change
for an iTPMS system to work (and they do work obviously). Now, we
don't need to define the situation by saying 'assuming no slip between
the tyre and the rim' as anyone who has tried to remove a tyre will
attest, nor do you have to state 'with no slip between the tyre and
the road' because if there was it would nearly be impossible to
predict anything. We certainly wouldn't need to mention anything about
the sidewall winding up because that will simply unwind again as the
torque (acceleration / braking) is removed.

So, we are down to *something* happening to effectively shorten the
effective circumference and about the only think logical (to any right
brainer that is) that at the point of the cord where the tyre flattens
out and the sidewall bulges where the tyre sits on the road, there is
a shortening of the tread length across this cord and hence a produce
a shorter 'effective rolling circumference'.

So, the left brainers deny this being even likely but without offering
any better solution themselves (and Turnip never will now of course,
not now he's backed himself into a very dark corner. Or he might, but
it will be that he has now come up with the answer all by himself).
;-)

On Thu, 28 Jun 2018 20:34:06 +1000, "Jeff" wrote:

snip

The thing is one is a function of the other (cause and effect).

Yes, but the change in the circumference is much smaller
than the change in the distance between the axle and
the road with an under inflated tyre

True?

and it would be obvious
which is controlling the measured rotation rate of the wheel.

Except it can only be the circumference that impacts the distance
traveled per revolution can't it? Anything else is consequential?

Cheers, T i m

"The Natural Philosopher" wrote in message
news
On 28/06/18 10:24, Jeff wrote:


"The Natural Philosopher" wrote in message
news
On 27/06/18 19:36, Tim Streater wrote:
You can also imagine that if you could get hold of a tire of the same
overall diameter but to go on a much smaller wheel, that the spiralling
effect when flat would be much more pronounced as the tire wall would
be bigger. But, once spiralled up, one turn

I've been thinking about this a lot trying to make it simple enough for
even a remoaner to understand.

The fallacy is in Huge's basic premise that because the axle is a given
height above te ground, that represents the 'effective/rolling radius*'
of the tyre.

It does not.

It does when considering the distance that determines the rotation rate
of the wheel.

The 'effective/rolling radius' is /always/ the circumference divided by
2 PI.

Not when it is the distance between the axle and the road that
determines the rotation rate of the wheel.

How can this be? Quite simply because the tyre is attached to the wheel
all round, and the tyre is dragged along by the sidewall such that the
tread is moving faster (angular velocity) than the rim at the point of
'flatness'.

So Huge's assumption that the tyre tread speed is actually it's distance
from the axis of rotation, times the speed of rotation of the wheel, is
simply a mistake. It is in fact *greater*, at that point, and its the
sidewall flexure that takes up the strain, and the attachment of the
tyre at other points of the rim that creates that strain.

Should the wheel deflate completely, then the strain in the sidewall and
the friction between the tread and the rim as the two models
compete...leads to rapid separation of tread and wheel.

You then end up then with a wheel rim and tyre tread rotating at
completely different angular velocity. The triumph of 'Huge's model' is
to rip the tyre sidewall apart to allow that to happen.


If you follow F1 you can see this regularly - you end up with the
sidewall disintegrating and a more or less intact tread separating from
the car wheel entirely.


This leads to the conclusions that what affects wheel RPM - in a non
slip case - apart from car speed, is change in *circumference* alone,
and that will be a function of tyre tread elasticity, tyre pressure and
tyre RPM only, due to 'centrifugal force'.

Loading won't affect it at all.

And whoever dreamt up 'effective' or 'rolling' radius deserves to be
strapped to a centrifuge.

A little knowledge is a dangerous thing.

So is relying on 'experts' who are equally ignorant.

But it is very easy to measure both a fully inflated tyre
and one that is say 20% under inflated and see if the
rotation rate of the wheel is in fact determined by the
distance between the axle and the road or the very
minimal change in the circumference of the tyre and
that must have been done when designing the ABS
system for detecting under inflated tyres.

Indeed. I see that my efforts are watsed and you havent understood a word
I said, nor even looked at the video I posted way back where someone did
precusely this and showed that within the limits of te technique,
flattening te tyre made no measureable difference

And yet we know that the TMPS system that uses the ABS sensors does
work to detect under inflated tyres very reliably.

- ceraiunly
not as much as the 'loss of radius' would account for. Nor yet te p[aper I
likned to that showed taht te differemnce with 30% deflation was of the
order of a percent or so. WAY less than would be accounted for by the
'loss of radius'



A lot of engineering is highly counter intuitive.

Doesnt matter when it is so easy measure.

Why don't you measure it then?

My car does have ABS, but doesnt show the instantaneous
rotation rate of each wheel on the OBD2 data.

I see that other people have, and that confirms my thesis.

What I wouuld ask you is how a tyre, rotating at a differentent rate from
a wheel, so that its circumference does in fact get covered on the ground
by that rotaion, stays on the wheel without ripping the tread off?

On 28/06/18 11:44, Jeff wrote:


"The Natural Philosopher" wrote in message
news
On 28/06/18 10:24, Jeff wrote:


"The Natural Philosopher" wrote in message
news On 27/06/18 19:36, Tim Streater wrote:
You can also imagine that if you could get hold of a tire of the same
overall diameter but to go on a much smaller wheel, that the
spiralling
effect when flat would be much more pronounced as the tire wall would
be bigger. But, once spiralled up, one turn

I've been thinking about this a lot trying to make it simple enough
for even a remoaner to understand.

The fallacy is in Huge's basic premise that because the axle is a
given height above te ground, that represents the 'effective/rolling
radius*' of the tyre.

It does not.

It does when considering the distance that determines the rotation
rate of the wheel.

The 'effective/rolling radius' is /always/ the circumference divided
by 2 PI.

Not when it is the distance between the axle and the road that
determines the rotation rate of the wheel.

How can this be? Quite simply because the tyre is attached to the
wheel all round, and the tyre is dragged along by the sidewall such
that the tread is moving faster (angular velocity) than the rim at
the point of 'flatness'.

So Huge's assumption that the tyre tread speed is actually it's
distance from the axis of rotation, times the speed of rotation of
the wheel, is simply a mistake. It is in fact *greater*, at that
point, and its the sidewall flexure that takes up the strain, and
the attachment of the tyre at other points of the rim that creates
that strain.

Should the wheel deflate completely, then the strain in the sidewall
and the friction between the tread and the rim as the two models
compete...leads to rapid separation of tread and wheel.

You then end up then with a wheel rim and tyre tread rotating at
completely different angular velocity. The triumph of 'Huge's model'
is to rip the tyre sidewall apart to allow that to happen.


If you follow F1 you can see this regularly - you end up with the
sidewall disintegrating and a more or less intact tread separating
from the car wheel entirely.


This leads to the conclusions that what affects wheel RPM -Â* in a
non slip case -Â* apart from car speed, is change in *circumference*
alone, and that will be a function of tyre tread elasticity, tyre
pressure and tyre RPM only, due to 'centrifugal force'.

Loading won't affect it at all.

And whoever dreamt up 'effective' or 'rolling' radius deserves to be
strapped to a centrifuge.

A little knowledge is a dangerous thing.

So is relying on 'experts' who are equally ignorant.

But it is very easy to measure both a fully inflated tyre
and one that is say 20% under inflated and see if the
rotation rate of the wheel is in fact determined by the
distance between the axle and the road or the very
minimal change in the circumference of the tyre and
that must have been done when designing the ABS
system for detecting under inflated tyres.

Indeed. I see that my efforts are watsed and you havent understood a
word I said, nor even looked at the video I posted way back where
someone did precusely this and showed that within the limits of te
technique, flattening te tyre made no measureable difference

And yet we know that the TMPS system that uses the ABS sensors does
work to detect under inflated tyres very reliably.

IF youy watch te video ytou will see that 'no measurable difference in
that video is less than 5% or so.

If you read the article I linked to it showed that 30% defltion was less
than 1% difference. This is detecatable by good software.

- ceraiunly
not as much as the 'loss of radius' would account for. Nor yet te
p[aper I likned to that showed taht te differemnce with 30% deflation
was of the order of a percent or so. WAY less than would be accounted
for by the 'loss of radius'



A lot of engineering is highly counter intuitive.

Doesnt matter when it is so easy measure.

Why don't you measure it then?

My car does have ABS, but doesnt show the instantaneous
rotation rate of each wheel on the OBD2 data.

You just have to put a chalk mark on the tyre and put another chaklkmark
on te ground, roll it forward a few revolutions, then flatten it by 30%
and roll it back to where it started. If you are correct the chalk
marks will be out by 10% or more. If I am right they will be damned near
lined up perfectly.


This threaad is not about the abilituy of software to detect a 1%
change, its about the claim by Huge and others that the tyre rotation
rate will cahnge by 10% or more depending in pressuer AND LOADING



I see that other people have, and that confirms my thesis.

What I wouuld ask you is how a tyre, rotating at a differentent rate
from a wheel, so that its circumference does in fact get covered on
the ground by that rotaion, stays on the wheel without ripping the
tread off?




--
There is nothing a fleet of dispatchable nuclear power plants cannot do
that cannot be done worse and more expensively and with higher carbon
emissions and more adverse environmental impact by adding intermittent
renewable energy.

"The Natural Philosopher" wrote in message
news
On 28/06/18 11:44, Jeff wrote:


"The Natural Philosopher" wrote in message
news
On 28/06/18 10:24, Jeff wrote:


"The Natural Philosopher" wrote in message
news On 27/06/18 19:36, Tim Streater wrote:
You can also imagine that if you could get hold of a tire of the same
overall diameter but to go on a much smaller wheel, that the
spiralling
effect when flat would be much more pronounced as the tire wall would
be bigger. But, once spiralled up, one turn

I've been thinking about this a lot trying to make it simple enough
for even a remoaner to understand.

The fallacy is in Huge's basic premise that because the axle is a
given height above te ground, that represents the 'effective/rolling
radius*' of the tyre.

It does not.

It does when considering the distance that determines the rotation rate
of the wheel.

The 'effective/rolling radius' is /always/ the circumference divided
by 2 PI.

Not when it is the distance between the axle and the road that
determines the rotation rate of the wheel.

How can this be? Quite simply because the tyre is attached to the
wheel all round, and the tyre is dragged along by the sidewall such
that the tread is moving faster (angular velocity) than the rim at the
point of 'flatness'.

So Huge's assumption that the tyre tread speed is actually it's
distance from the axis of rotation, times the speed of rotation of the
wheel, is simply a mistake. It is in fact *greater*, at that point,
and its the sidewall flexure that takes up the strain, and the
attachment of the tyre at other points of the rim that creates that
strain.

Should the wheel deflate completely, then the strain in the sidewall
and the friction between the tread and the rim as the two models
compete...leads to rapid separation of tread and wheel.

You then end up then with a wheel rim and tyre tread rotating at
completely different angular velocity. The triumph of 'Huge's model'
is to rip the tyre sidewall apart to allow that to happen.


If you follow F1 you can see this regularly - you end up with the
sidewall disintegrating and a more or less intact tread separating
from the car wheel entirely.


This leads to the conclusions that what affects wheel RPM - in a non
slip case - apart from car speed, is change in *circumference* alone,
and that will be a function of tyre tread elasticity, tyre pressure
and tyre RPM only, due to 'centrifugal force'.

Loading won't affect it at all.

And whoever dreamt up 'effective' or 'rolling' radius deserves to be
strapped to a centrifuge.

A little knowledge is a dangerous thing.

So is relying on 'experts' who are equally ignorant.

But it is very easy to measure both a fully inflated tyre
and one that is say 20% under inflated and see if the
rotation rate of the wheel is in fact determined by the
distance between the axle and the road or the very
minimal change in the circumference of the tyre and
that must have been done when designing the ABS
system for detecting under inflated tyres.

Indeed. I see that my efforts are watsed and you havent understood a
word I said, nor even looked at the video I posted way back where
someone did precusely this and showed that within the limits of te
technique, flattening te tyre made no measureable difference

And yet we know that the TMPS system that uses the ABS sensors does
work to detect under inflated tyres very reliably.

IF youy watch te video ytou will see that 'no measurable difference in
that video is less than 5% or so.

If you read the article I linked to it showed that 30% defltion was less
than 1% difference. This is detecatable by good software.

- ceraiunly
not as much as the 'loss of radius' would account for. Nor yet te p[aper
I likned to that showed taht te differemnce with 30% deflation was of
the order of a percent or so. WAY less than would be accounted for by
the 'loss of radius'



A lot of engineering is highly counter intuitive.

Doesnt matter when it is so easy measure.

Why don't you measure it then?

My car does have ABS, but doesnt show the instantaneous
rotation rate of each wheel on the OBD2 data.

You just have to put a chalk mark on the tyre and put another chaklkmark
on te ground, roll it forward a few revolutions, then flatten it by 30%
and roll it back to where it started. If you are correct the chalk marks
will be out by 10% or more. If I am right they will be damned near lined
up perfectly.

What matters is the rotation rate of the wheel, because that
is what the ABS sensors are measuring.

This threaad is not about the abilituy of software to detect a 1% change,
its about the claim by Huge and others that the tyre rotation rate will
cahnge by 10% or more depending in pressuer AND LOADING



I see that other people have, and that confirms my thesis.

What I wouuld ask you is how a tyre, rotating at a differentent rate
from a wheel, so that its circumference does in fact get covered on the
ground by that rotaion, stays on the wheel without ripping the tread
off?

In article 20180627224721.070920bf@Mars,
Rob Morley wrote:
On Wed, 27 Jun 2018 18:46:43 +0100
"NY" wrote:

My present Pug had a failed clutch actuator mechanism (**) - failed
in-gear as I was setting off at the head of a queue of traffic at
lights, so without the ability to disengage the clutch, the car was
stuck in gear and I was stuck blocking the junction.

Why could you not just knock it out of gear?

Or motor it out of the way using the starter.

--
*He who laughs last has just realised the joke.

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

In article ,
NY wrote:
"Rob Morley" wrote in message
news:20180627224721.070920bf@Mars...
On Wed, 27 Jun 2018 18:46:43 +0100
"NY" wrote:

My present Pug had a failed clutch actuator mechanism (**) - failed
in-gear as I was setting off at the head of a queue of traffic at
lights, so without the ability to disengage the clutch, the car was
stuck in gear and I was stuck blocking the junction.

Why could you not just knock it out of gear?

With all the cars I've ever owned, if you happen to stall the engine in
gear with the clutch up, the gear lever jams and is only released if
you press the clutch.

Just rock the car back and forth slightly while moving the gear lever. But
might be tricky on a hill.

--
*A cartoonist was found dead in his home. Details are sketchy.*

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

In article ,
T i m wrote:
and it would be obvious
which is controlling the measured rotation rate of the wheel.

Except it can only be the circumference that impacts the distance
traveled per revolution can't it? Anything else is consequential?

ABS sensors have multiple teeth. If all you needed to do is measure the
speed of the wheel per revolution, one tooth would do just fine.

--
*How many roads must a man travel down before he admits he is lost? *

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

"Dave Plowman (News)" wrote in message
...
My present Pug had a failed clutch actuator mechanism (**) - failed
in-gear as I was setting off at the head of a queue of traffic at
lights, so without the ability to disengage the clutch, the car was
stuck in gear and I was stuck blocking the junction.

Why could you not just knock it out of gear?

With all the cars I've ever owned, if you happen to stall the engine in
gear with the clutch up, the gear lever jams and is only released if
you press the clutch.

Just rock the car back and forth slightly while moving the gear lever. But
might be tricky on a hill.

This was on just enough of a hill to make it impossible. The weight of the
car was pressing the car downhill, so I'd have had to move it uphill to
relieve the pressure on the dog clutches, and then hurry back to the car to
knock it out of gear before rolled back again and re-created the problem

I was lucky. After a lot of working of the clutch pedal against a very weak
spring (probably in the pedal itself) I *eventually* felt a much stronger
pressure of the springs in the clutch, so I reasoned that I'd managed to
disengage the clutch and would be able to take the car out of gear - which I
could. The next time I tried the pedal, it wasn't working again, so I'd been
lucky in hitting the one time that the mechanism worked. I then had to let
the car roll backwards to the side of the road, to await the RAC and a tow
to the garage. I managed to catch someone still at the garage who booked the
car in, and the RAC man then gave me a lift home which was about 20 miles
away (so above and beyond the call of duty). That bridge and set of traffic
lights where it happened (approaching the railway station in Scarborough) is
now know as "Pug's Bridge" and my wife and I joke "Pug, no breaking down
here just so you can have another holiday by the sea" -)

"Dave Plowman (News)" wrote in message
...
In article ,
T i m wrote:
and it would be obvious
which is controlling the measured rotation rate of the wheel.

Except it can only be the circumference that impacts the distance
traveled per revolution can't it? Anything else is consequential?

ABS sensors have multiple teeth. If all you needed to do is measure the
speed of the wheel per revolution, one tooth would do just fine.

Except that multiple teeth allow a quicker reading of any change, without
having to wait (potentially) a full wheel revolution before noticing that
something had changed. For ABS, there are big advantages in reducing the
time between the change occurring (ie one wheel spinning faster than all the
others) and being able to detect this so you can do something about it.

On 28/06/2018 09:46, The Natural Philosopher wrote:
On 27/06/18 19:36, Tim Streater wrote:
You can also imagine that if you could get hold of a tire of the same
overall diameter but to go on a much smaller wheel, that the spiralling
effect when flat would be much more pronounced as the tire wall would
be bigger. But, once spiralled up, one turn

I've been thinking about this a lot trying to make it simple enough for
even a remoaner to understand.

The fallacy is in Huge's basic premise that because the axle is a given
height above te ground, that represents the 'effective/rolling radius*'
of the tyre.

It does not.

The 'effective/rolling radius' is /always/ the circumference divided by
2 PI.

Rubbish.

The tread on the tyre and the side walls deform as the tyre rotates
changing the actual circumference.
The change depends on the contact length which changes with pressure,
load, tread pattern, rubber compound, type of belts, etc.

Even a steel tyre like those on trains deforms as it rotates.

On 28/06/2018 10:59, The Natural Philosopher wrote:


What I wouuld ask you is how a tyre, rotating at a differentent rate
from a wheel, so that its circumference does in fact get covered on the
ground by that rotaion, stays on the wheel without ripping the tread off?


This "philosopher" hasn't ever noticed the tyre debris on the roads
where the tread has been ripped off.

Maybe he wants to explain why it happens to lorries with twin wheels
where only one tyre has gone flat but is being kept at about the correct
radius by the other wheel?

On 28/06/18 12:11, Jeff wrote:
What matters is the rotation rate of the wheel, because that
is what the ABS sensors are measuring.
No. In the context iof this thread it is utterly irrelvant.#

But we don't disagree that the rate changes. Only by how much, and why.



--
Gun Control: The law that ensures that only criminals have guns.

On 28/06/18 16:20, Tim Streater wrote:
In article , "dennis@home" wrote:

On 27/06/2018 22:11, T i m wrote:
On Wed, 27 Jun 2018 19:50:37 +0100, Andy Burns
wrote:

Tim Streater wrote:

The problem we have on this ng is too many unimaginative dimwits

Yeah, better that we have some whose imagination is so powerful, they
can dream up ways to say that a device that plainly does work, cannot
possibly work ...

It seems the self confessed 'know it all's' are tripping over
themselves to disprove reality on this one Andy. ;-)

They all seem so very keen to deny the *facts* put forward by the
experts in the field (and those of us who can understand them) but
completely fail to come up with an alternative explanation themselves
(well, not that a 5yr old couldn't see though, like Streaters last
droolings). ;-)

I seeÂ* T r o l lÂ* continues to be unable to actually argue the point.


No dennis is a man of limited intelligence who runs on received wisdom
because he cant think for himself. Such education he has had has been
learning by rote only, and he therefore thinks that being right is a
matter of listening to the right authjority. He will probably listen to
the BBC, read the Guardian and believes that it is a disater to leave
the EU and that mab made global warming is real, not because he has
examined the evidence, but because that is what he has been told, endlessly.


--
Gun Control: The law that ensures that only criminals have guns.

On 28/06/2018 17:44, The Natural Philosopher wrote:
On 28/06/18 16:20, Tim Streater wrote:
In article , "dennis@home" wrote:

On 27/06/2018 22:11, T i m wrote:
On Wed, 27 Jun 2018 19:50:37 +0100, Andy Burns
wrote:

Tim Streater wrote:

The problem we have on this ng is too many unimaginative dimwits

Yeah, better that we have some whose imagination is so powerful, they
can dream up ways to say that a device that plainly does work, cannot
possibly work ...

It seems the self confessed 'know it all's' are tripping over
themselves to disprove reality on this one Andy. ;-)

They all seem so very keen to deny the *facts* put forward by the
experts in the field (and those of us who can understand them) but
completely fail to come up with an alternative explanation themselves
(well, not that a 5yr old couldn't see though, like Streaters last
droolings). ;-)

I seeÂ* T r o l lÂ* continues to be unable to actually argue the point.


No dennis is a man of limited intelligence who runs on received wisdom
because he cant think for himself. Such education he has had has been
learning by rote only, and he therefore thinks that being right is a
matter of listening to the right authjority. He will probably listen to
the BBC, read the Guardian and believes that it is a disater to leave
the EU and that mab made global warming is real, not because he has
examined the evidence, but because that is what he has been told,
endlessly.



The TNP areshole is wrong as usual, and resorting to stupid attacks over
something I haven't said because is is wrong and is trying to divert
everyone away from the fact he is wrong like he always does.

On 28/06/2018 17:41, The Natural Philosopher wrote:
On 28/06/18 12:11, Jeff wrote:
What matters is the rotation rate of the wheel, because that
is what the ABS sensors are measuring.
No. In the context iof this thread it is utterly irrelvant.#

But we don't disagree that the rate changes. Only by how much, and why.




Here TNP goes.. all through the thread he has claimed there is no effect
and now he claims there is an effect and has done so all along.

On 28/06/2018 16:40, Tim Streater wrote:
In article , "dennis@home" wrote:

On 28/06/2018 10:59, The Natural Philosopher wrote:

What I wouuld ask you is how a tyre, rotating at a differentent rate
from a wheel, so that its circumference does in fact get covered on
the ground by that rotaion, stays on the wheel without ripping the
tread off?

This "philosopher" hasn't ever noticed the tyre debris on the roads
where the tread has been ripped off.

Maybe he wants to explain why it happens to lorries with twin wheels
where only one tyre has gone flat but is being kept at about the
correct radius by the other wheel?

Ah, nice attempt at a shimmy there, Den. Our Dave would be proud of you.

What you're in fact admitting is that the wheel and the tire *must*
rotate at the same rate, otherwise the tread would come off.


How dumb can you be to think that is what I said?
I said the exact opposite of what you chose to claim I said.

Are you TNP ?

"The Natural Philosopher" wrote in message
news
On 28/06/18 12:11, Jeff wrote:
What matters is the rotation rate of the wheel, because that
is what the ABS sensors are measuring.
No. In the context iof this thread it is utterly irrelvant.#

But we don't disagree that the rate changes. Only by how much, and why.

And when you measure how much the rate changes, that will
tell you if it is changing due to the change in circumference or
the change in the distance between the axle and the road because
one changes much more than the other with under pressure.

On Thu, 28 Jun 2018 19:19:45 +0100, "dennis@home"
wrote:
snip

The TNP areshole is wrong as usual, and resorting to stupid attacks over
something I haven't said because is is wrong and is trying to divert
everyone away from the fact he is wrong like he always does.

Bingo.

I was walking round the park with our daughter earlier and I gave her
the nutshell iTPMS overview and asked her how she thought it might
work ... how the circumference could become shorter for the iTPMS to
'sense' the increased RPM.

"As the tyre gets flatter it spreads more and that makes the
circumference shorter and so the revs higher?"

A 27yr old girl gave the right answer instantly when the combined
brains of Turnip and his goblin Streater still cannot!

Bwhahahahahaha ... !!!

Cheers, T i m

On Thu, 28 Jun 2018 19:21:57 +0100, "dennis@home"
wrote:

On 28/06/2018 17:41, The Natural Philosopher wrote:
On 28/06/18 12:11, Jeff wrote:
What matters is the rotation rate of the wheel, because that
is what the ABS sensors are measuring.
No. In the context iof this thread it is utterly irrelvant.#

But we don't disagree that the rate changes. Only by how much, and why.




Here TNP goes.. all through the thread he has claimed there is no effect
and now he claims there is an effect and has done so all along.

Yup, but he can't help it. He is a left brainer and so will both back
himself into a corner and argue black is white until the penny
eventually drops and then as you say (and I said a while back) will
gradually skew his BS to make it look like he had the answer from the
beginning (bit still asked the question)?

It would be sad if he wasn't already a laughing stock. ;-)

Cheers, T i m