On 14/02/2019 08:38, The Natural Philosopher wrote:


A one in ten hill is so steep that most people would slow right down on it.




M25 going downhill 10% near Reigate golf course:-
https://goo.gl/maps/EnCnpc3Vy1z

Andy Bennet formulated on Thursday :
Only trust the satnav speed when on a level road. The speed is calculated by
rate of change of position on a flat surface. If you are going up or down a
hill it will under read.

Yes, it does make a difference, but for all practical purposes can be
ignored. The major difference to be taken into account, is acceleration
and deceleration - they provide accurate readings only at steady
speeds.


The derivation of altitude via GPS is not very accurate anyway and is ignored
in domestic satnav devices.

Correct, mine shows the altitude, but rarely moves from 114 feet ASL
irrespective of where it goes.

Dave Plowman wrote:

a very optimistic speedo. Some makers today do just the same.
When making one which is within 1% accuracy should be child's play since
they are counting pulses.

Mine shows true speed minus 1 mph, compared to GPS speed and to those
annoying signs that flash to thank you for being considerate.

Dave Plowman (News) brought next idea :
So you start out with a speedo dead accurate with new tyres. Then the
maximum error would be 2%. Not 10% as allowed. Things have moved on since
that reg was written.

It was written with in mind a cable drive from the back of gearbox and
an instrument which used a cable driven magnet and a clock-spring.
Rather than the precise electronics we can make so easily these days..

"Steve Walker" wrote in message
...
On 13/02/2019 21:19, wrote:
On Wednesday, 13 February 2019 12:27:03 UTC, wrote:

Overheard someone talking to someone that was going to supply her a
temporary vehicle. She was very concerned that the car should be at
least a 2.0 as she intends to dive on the motorway.

I assume they offered a beemer, because she said

€œI dont know anything about BMWs I drive a Jaguar.
I dont know if they can be driven on the motorway.€�


How the other half lives! I used to take my 1.0 Metros from London to
Preston & back on the motorway on a regular basis (leaving Jaguars and
BMs eating my lead!)

Luxury! I used to do long journeys in a thing with a wooden floor that
topped out at 52mph. Eventually.

One guy I worked with drove from Manchester to deepest Cornwall and back
in one of those small, 4-wheel, rear-steer cranes with a top speed of
12mph !!!

I bet he was popular when he was on single-carriageway roads where
overtaking isn't easy.

Is it my imagination or are drivers of abnormally slow vehicles (eg
tractors) less willing to pull into a layby to let faster traffic past? I
used to see tractors pulling very large, heavy (possibly overloaded)
trailers along the single-carriageway sections of the A64 and it was *very*
rare that they would pull off anywhere between Malton and York - and three
are very few sections of that road that have a long enough straight section
to allow safe overtaking.

I wish the law would be changed to say that tractors are only allowed on the
road for short journeys between one field and another of a farm, and that
for all longer-distance journeys trailers had to be hauled by a lorry that
was capable of reaching the speed limit, rather than a tractor with (at
best) a top speed of 30.

The Natural Philosopher Wrote in message:
On 14/02/2019 08:34, Andy Bennet wrote:
On 13/02/2019 19:19, Harry Bloomfield wrote:
Robin has brought this to us :
I find it hard to see how a simple count of pulses can deliver 1 per
cent accuracy.

My does around 50 pulses per revolution of the wheel, there are
electronic methods to predict the likely next pulse period and predict
when the next pulse will arrive. I have three speed displays available
to me - the dial on the dash, which reads a few percent high, digital
display which does not interpret the wheel pulses at all, it just
displays the value and entirely independently - satnav. The latter two
always agree within 1mph at a steady speed.

Only trust the satnav speed when on a level road. The speed is
calculated by rate of change of position on a flat surface. If you are
going up or down a hill it will under read.

The derivation of altitude via GPS is not very accurate anyway and is
ignored in domestic satnav devices.

A one in ten hill is so steep that most people would slow right down on it.

A one in ten hill would underead by 10%. In essence practically
negligible on any normal slope of 1 in 100 or so.

A 1 in 10 "hill" bwahahahaha :-D

You should get out more
--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

"FMurtz" wrote in message
...
alan_m wrote:
On 13/02/2019 18:12, Robin wrote:

depends on wheel/tyre of course but I was reckoning on tread going from
8mm to 2mm on a tyre of around 180mm circumference.


What about different minor variants of the same basic car? It wouldn't
be unusual for them to be fitted with either,say, 16 or 17 inch wheels.

Same external diameter.

Do the manufactures adjust the calibration for different factory fitted
wheels or do they rely of range they allowed on the speedo readings?

What about the reading within spec with a space-saver wheel on one corner

Still hopefully the same external diameter, otherwise the car would (try to)
go round in circles.

On Wednesday, 13 February 2019 23:14:20 UTC, Steve Walker wrote:
On 13/02/2019 21:19, tabbypurr wrote:
On Wednesday, 13 February 2019 12:27:03 UTC, wrote:

Overheard someone talking to someone that was going to supply her a temporary vehicle. She was very concerned that the car should be at least a 2.0 as she intends to dive on the motorway.

I assume they offered a beemer, because she said

€œI dont know anything about BMWs I drive a Jaguar.
I dont know if they can be driven on the motorway.€�


How the other half lives! I used to take my 1.0 Metros from London to Preston & back on the motorway on a regular basis (leaving Jaguars and BMs eating my lead!)

Luxury! I used to do long journeys in a thing with a wooden floor that topped out at 52mph. Eventually.

One guy I worked with drove from Manchester to deepest Cornwall and back
in one of those small, 4-wheel, rear-steer cranes with a top speed of
12mph !!!

SteveW

sheesh, I hope it was worth his time.


NT

On Thursday, 14 February 2019 08:52:43 UTC, Andy Bennet wrote:
On 14/02/2019 08:38, The Natural Philosopher wrote:

A one in ten hill is so steep that most people would slow right down on it.

M25 going downhill 10% near Reigate golf course:-
https://goo.gl/maps/EnCnpc3Vy1z

no way. Maybe that sign applies to the ramp or a turn-off.


NT

On Thursday, 14 February 2019 09:25:49 UTC, NY wrote:

One guy I worked with drove from Manchester to deepest Cornwall and back
in one of those small, 4-wheel, rear-steer cranes with a top speed of
12mph !!!

I bet he was popular when he was on single-carriageway roads where
overtaking isn't easy.

Is it my imagination or are drivers of abnormally slow vehicles (eg
tractors) less willing to pull into a layby to let faster traffic past? I
used to see tractors pulling very large, heavy (possibly overloaded)
trailers along the single-carriageway sections of the A64 and it was *very*
rare that they would pull off anywhere between Malton and York - and three
are very few sections of that road that have a long enough straight section
to allow safe overtaking.

I wish the law would be changed to say that tractors are only allowed on the
road for short journeys between one field and another of a farm, and that
for all longer-distance journeys trailers had to be hauled by a lorry that
was capable of reaching the speed limit, rather than a tractor with (at
best) a top speed of 30.

There's already a law to deal with it. Adding another is not the solution.

On Thu, 14 Feb 2019 01:56:30 -0800, tabbypurr wrote:

On Thursday, 14 February 2019 08:52:43 UTC, Andy Bennet wrote:
On 14/02/2019 08:38, The Natural Philosopher wrote:

A one in ten hill is so steep that most people would slow right down
on it.

M25 going downhill 10% near Reigate golf course:-
https://goo.gl/maps/EnCnpc3Vy1z

no way. Maybe that sign applies to the ramp or a turn-off.

Actually, it is. People complain about the slow traffic in the opposite
direction (although it isn't quite as bad, as the carriageways diverge a
bit).



--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

On Thursday, 14 February 2019 10:04:57 UTC, Bob Eager wrote:
On Thu, 14 Feb 2019 01:56:30 -0800, tabbypurr wrote:
On Thursday, 14 February 2019 08:52:43 UTC, Andy Bennet wrote:
On 14/02/2019 08:38, The Natural Philosopher wrote:

A one in ten hill is so steep that most people would slow right down
on it.

M25 going downhill 10% near Reigate golf course:-
https://goo.gl/maps/EnCnpc3Vy1z

no way. Maybe that sign applies to the ramp or a turn-off.

Actually, it is. People complain about the slow traffic in the opposite
direction (although it isn't quite as bad, as the carriageways diverge a
bit).

https://www.ice.org.uk/what-is-civil...o/uk-motorways
"The steepest part of the network is between the Shore Road and Sandyknowes section of the M2 in Northern Ireland. The gradient reaches 1 in 19.5% (5.13%) in places."

Star Hill is about 10%, that may be what it refers to.
No sane person would drive at 70 down a 10% incline.


NT

On 14/02/2019 10:32, wrote:
On Thursday, 14 February 2019 10:04:57 UTC, Bob Eager wrote:
On Thu, 14 Feb 2019 01:56:30 -0800, tabbypurr wrote:
On Thursday, 14 February 2019 08:52:43 UTC, Andy Bennet wrote:
On 14/02/2019 08:38, The Natural Philosopher wrote:

A one in ten hill is so steep that most people would slow right down
on it.

M25 going downhill 10% near Reigate golf course:-
https://goo.gl/maps/EnCnpc3Vy1z

no way. Maybe that sign applies to the ramp or a turn-off.

Actually, it is. People complain about the slow traffic in the opposite
direction (although it isn't quite as bad, as the carriageways diverge a
bit).

https://www.ice.org.uk/what-is-civil...o/uk-motorways
"The steepest part of the network is between the Shore Road and Sandyknowes section of the M2 in Northern Ireland. The gradient reaches 1 in 19.5% (5.13%) in places."

Star Hill is about 10%, that may be what it refers to.
No sane person would drive at 70 down a 10% incline.



Call me insane but I have been both up and down it at well over 71mph.

wrote in message
...
On Thursday, 14 February 2019 09:25:49 UTC, NY wrote:

I wish the law would be changed to say that tractors are only allowed on
the
road for short journeys between one field and another of a farm, and that
for all longer-distance journeys trailers had to be hauled by a lorry
that
was capable of reaching the speed limit, rather than a tractor with (at
best) a top speed of 30.

There's already a law to deal with it. Adding another is not the solution.

What exactly *is* the law about using tractors for long-distance haulage (eg
from field to processing plant or remote barn) instead of using a road-going
lorry and road-going trailer?

Am I right, incidentally, that all trailers used on the road must have
proper rear lights (tail/indicator) and number plate? Or is an exception
made for tractors to allow for a fleet of tractors being used with the same
trailer and to avoid having to connect/disconnect cables each time the
tractor/trailer are uncoupled?

The problem has got worse now that farmers have fields in various places
which are many miles from the storage barn, rather than the barn being
adjacent to the fields where crops were grown, as happened in the past.

The farmer that grew barley/wheat in the fields behind our old house had a
fleet of tractors and grain trailers taking the outflow from the combine
harvester to his "base" which was probably about 10 miles away along fairly
narrow roads.

Is there any legal requirement for drivers of slow-moving vehicles (for some
definition of "slow") to pull over whenever possible to let traffic past? Or
is it just a strongly-worded recommendation in the Highway Code, without any
legal "teeth" behind it and which is at the discretion and bloody-mindedness
of the driver? My wife used to work on a farm in the 1990s and it was
drummed into them that they *must* be courteous to other drivers and pull in
whenever they could.

Around York there used to be horrendous problems at sugar-beet times when
farmers would use their own tractors to take their trailers of sugar beet to
the central processing plant (now closed down) on the outskirts of York,
causing big traffic holdups. I wonder if the same problem happens/happened
at the one in Newark that we sometimes drive past.

Obviously tractors are not allowed on motorways, but you still get them on
motorway-standard dual carriageways - and huge queues as everyone has to get
over into the other lane to get past a tractor trundling along at 20 on a
road where most traffic is doing 70 (or maybe a bit more if the police
aren't checking).

On Thursday, February 14, 2019 at 9:25:49 AM UTC, NY wrote:
"Steve Walker" wrote in message
...
On 13/02/2019 21:19, wrote:
On Wednesday, 13 February 2019 12:27:03 UTC, wrote:

Overheard someone talking to someone that was going to supply her a
temporary vehicle. She was very concerned that the car should be at
least a 2.0 as she intends to dive on the motorway.

I assume they offered a beemer, because she said

€œI dont know anything about BMWs I drive a Jaguar.
I dont know if they can be driven on the motorway.€�


How the other half lives! I used to take my 1.0 Metros from London to
Preston & back on the motorway on a regular basis (leaving Jaguars and
BMs eating my lead!)

Luxury! I used to do long journeys in a thing with a wooden floor that
topped out at 52mph. Eventually.

One guy I worked with drove from Manchester to deepest Cornwall and back
in one of those small, 4-wheel, rear-steer cranes with a top speed of
12mph !!!

I bet he was popular when he was on single-carriageway roads where
overtaking isn't easy.

Is it my imagination or are drivers of abnormally slow vehicles (eg
tractors) less willing to pull into a layby to let faster traffic past? I
used to see tractors pulling very large, heavy (possibly overloaded)
trailers along the single-carriageway sections of the A64 and it was *very*
rare that they would pull off anywhere between Malton and York - and three
are very few sections of that road that have a long enough straight section
to allow safe overtaking.

I wish the law would be changed to say that tractors are only allowed on the
road for short journeys between one field and another of a farm, and that
for all longer-distance journeys trailers had to be hauled by a lorry that
was capable of reaching the speed limit, rather than a tractor with (at
best) a top speed of 30.

No its the selfish cyclists in their peloton who wouldn't dream of single filing to let traffic through. And they wonder why motorists hate them.

Actually I think there should be a law that pelotons have to go single file whne in 30mph zones.

On Thursday, 14 February 2019 10:38:11 UTC, Andy Bennet wrote:
On 14/02/2019 10:32, tabbypurr wrote:
On Thursday, 14 February 2019 10:04:57 UTC, Bob Eager wrote:
On Thu, 14 Feb 2019 01:56:30 -0800, tabbypurr wrote:
On Thursday, 14 February 2019 08:52:43 UTC, Andy Bennet wrote:
On 14/02/2019 08:38, The Natural Philosopher wrote:

A one in ten hill is so steep that most people would slow right down
on it.

M25 going downhill 10% near Reigate golf course:-
https://goo.gl/maps/EnCnpc3Vy1z

no way. Maybe that sign applies to the ramp or a turn-off.

Actually, it is. People complain about the slow traffic in the opposite
direction (although it isn't quite as bad, as the carriageways diverge a
bit).

https://www.ice.org.uk/what-is-civil...o/uk-motorways
"The steepest part of the network is between the Shore Road and Sandyknowes section of the M2 in Northern Ireland. The gradient reaches 1 in 19.5% (5.13%) in places."

Star Hill is about 10%, that may be what it refers to.
No sane person would drive at 70 down a 10% incline.



Call me insane but I have been both up and down it at well over 71mph.

The M25 I don't doubt it. A 10% incline I hope not - at least not on the public road.


NT

On Thursday, 14 February 2019 10:38:51 UTC, NY wrote:
tabbypurr wrote in message
...
On Thursday, 14 February 2019 09:25:49 UTC, NY wrote:

I wish the law would be changed to say that tractors are only allowed on
the
road for short journeys between one field and another of a farm, and that
for all longer-distance journeys trailers had to be hauled by a lorry
that
was capable of reaching the speed limit, rather than a tractor with (at
best) a top speed of 30.

There's already a law to deal with it. Adding another is not the solution.

What exactly *is* the law about using tractors for long-distance haulage (eg
from field to processing plant or remote barn) instead of using a road-going
lorry and road-going trailer?

Am I right, incidentally, that all trailers used on the road must have
proper rear lights (tail/indicator) and number plate? Or is an exception
made for tractors to allow for a fleet of tractors being used with the same
trailer and to avoid having to connect/disconnect cables each time the
tractor/trailer are uncoupled?

The problem has got worse now that farmers have fields in various places
which are many miles from the storage barn, rather than the barn being
adjacent to the fields where crops were grown, as happened in the past.

The farmer that grew barley/wheat in the fields behind our old house had a
fleet of tractors and grain trailers taking the outflow from the combine
harvester to his "base" which was probably about 10 miles away along fairly
narrow roads.

Is there any legal requirement for drivers of slow-moving vehicles (for some
definition of "slow") to pull over whenever possible to let traffic past? Or
is it just a strongly-worded recommendation in the Highway Code, without any
legal "teeth" behind it and which is at the discretion and bloody-mindedness
of the driver? My wife used to work on a farm in the 1990s and it was
drummed into them that they *must* be courteous to other drivers and pull in
whenever they could.

Around York there used to be horrendous problems at sugar-beet times when
farmers would use their own tractors to take their trailers of sugar beet to
the central processing plant (now closed down) on the outskirts of York,
causing big traffic holdups. I wonder if the same problem happens/happened
at the one in Newark that we sometimes drive past.

Obviously tractors are not allowed on motorways, but you still get them on
motorway-standard dual carriageways - and huge queues as everyone has to get
over into the other lane to get past a tractor trundling along at 20 on a
road where most traffic is doing 70 (or maybe a bit more if the police
aren't checking).

Any vehicle that's holding traffic up must let them pass.


NT

In article ,
FMurtz wrote:
So you start out with a speedo dead accurate with new tyres. Then the
maximum error would be 2%. Not 10% as allowed. Things have moved on
since that reg was written.

They start out never true speed reading,they always read less, except
for police speedos in police vehicles.

In years gone by a speedometer was a precision mechanical device. Making
it accurate expensive. Not so with electronics. Even more so when many
makes have a very consistent error.

--
*A backward poet writes inverse.*

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

In article ,
Andy Burns wrote:
Mine shows true speed minus 1 mph, compared to GPS speed and to those
annoying signs that flash to thank you for being considerate.

There's one round here that flashes saying you're exceeding the limit even
at 20 mph - in a 30 MPH zone. One of the older types which all seemed to
do that.

The newer ones which show your actual speed and a smiley etc, do seem
rather better.

--
*Income tax service - We‘ve got what it takes to take what you've got.

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

In article ,
Harry Bloomfield wrote:
Dave Plowman (News) brought next idea :
So you start out with a speedo dead accurate with new tyres. Then the
maximum error would be 2%. Not 10% as allowed. Things have moved on since
that reg was written.

It was written with in mind a cable drive from the back of gearbox and
an instrument which used a cable driven magnet and a clock-spring.
Rather than the precise electronics we can make so easily these days..

Quite. Although even eddy current speedos could be far more accurate than
that spec.

Then there were chronometric ones. You'd laugh at a clock which couldn't
better 10% accuracy even in the 19th century.

--
*Can fat people go skinny-dipping?

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

"NY" Wrote in message:
"FMurtz" wrote in message
...
alan_m wrote:
On 13/02/2019 18:12, Robin wrote:

depends on wheel/tyre of course but I was reckoning on tread going from
8mm to 2mm on a tyre of around 180mm circumference.


What about different minor variants of the same basic car? It wouldn't
be unusual for them to be fitted with either,say, 16 or 17 inch wheels.

Same external diameter.

Do the manufactures adjust the calibration for different factory fitted
wheels or do they rely of range they allowed on the speedo readings?

What about the reading within spec with a space-saver wheel on one corner

Still hopefully the same external diameter, otherwise the car would (try to)
go round in circles.



We call them differentials...
--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

Wrote in message:
On Thursday, 14 February 2019 10:38:51 UTC, NY wrote:
tabbypurr wrote in message
...
On Thursday, 14 February 2019 09:25:49 UTC, NY wrote:

I wish the law would be changed to say that tractors are only allowed on
the
road for short journeys between one field and another of a farm, and that
for all longer-distance journeys trailers had to be hauled by a lorry
that
was capable of reaching the speed limit, rather than a tractor with (at
best) a top speed of 30.

There's already a law to deal with it. Adding another is not the solution.

What exactly *is* the law about using tractors for long-distance haulage (eg
from field to processing plant or remote barn) instead of using a road-going
lorry and road-going trailer?

Am I right, incidentally, that all trailers used on the road must have
proper rear lights (tail/indicator) and number plate? Or is an exception
made for tractors to allow for a fleet of tractors being used with the same
trailer and to avoid having to connect/disconnect cables each time the
tractor/trailer are uncoupled?

The problem has got worse now that farmers have fields in various places
which are many miles from the storage barn, rather than the barn being
adjacent to the fields where crops were grown, as happened in the past.

The farmer that grew barley/wheat in the fields behind our old house had a
fleet of tractors and grain trailers taking the outflow from the combine
harvester to his "base" which was probably about 10 miles away along fairly
narrow roads.

Is there any legal requirement for drivers of slow-moving vehicles (for some
definition of "slow") to pull over whenever possible to let traffic past? Or
is it just a strongly-worded recommendation in the Highway Code, without any
legal "teeth" behind it and which is at the discretion and bloody-mindedness
of the driver? My wife used to work on a farm in the 1990s and it was
drummed into them that they *must* be courteous to other drivers and pull in
whenever they could.

Around York there used to be horrendous problems at sugar-beet times when
farmers would use their own tractors to take their trailers of sugar beet to
the central processing plant (now closed down) on the outskirts of York,
causing big traffic holdups. I wonder if the same problem happens/happened
at the one in Newark that we sometimes drive past.

Obviously tractors are not allowed on motorways, but you still get them on
motorway-standard dual carriageways - and huge queues as everyone has to get
over into the other lane to get past a tractor trundling along at 20 on a
road where most traffic is doing 70 (or maybe a bit more if the police
aren't checking).

Any vehicle that's holding traffic up must let them pass.


NT


No wonder there's a problem...
--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

On Wed, 13 Feb 2019 04:27:00 -0800 (PST), wrote:

Overheard someone talking to someone that was going to supply her a tempora=
ry vehicle. She was very concerned that the car should be at least a 2.0 a=
s she intends to dive on the motorway. =20

I assume they offered a beemer, because she said

=E2=80=9CI don=E2=80=99t know anything about BMW=E2=80=99s I drive a Jaguar=
.=20
I don=E2=80=99t know if they can be driven on the motorway.=E2=80=9D


How the other half lives! I used to take my 1.0 Metros from London to Pres=
ton & back on the motorway on a regular basis (leaving Jaguars and BMs eati=
ng my lead!)

Back in the day it was an 848cc A35 van, then same size Mini. What a
waste in the days when the black diagonal really meant no speed limit.


--
AnthonyL

Bob Eager wrote:

On Thu, 14 Feb 2019 01:56:30 -0800, tabbypurr wrote:

On Thursday, 14 February 2019 08:52:43 UTC, Andy Bennet wrote:
On 14/02/2019 08:38, The Natural Philosopher wrote:

A one in ten hill is so steep that most people would slow right down
on it.

M25 going downhill 10% near Reigate golf course:-
https://goo.gl/maps/EnCnpc3Vy1z

no way. Maybe that sign applies to the ramp or a turn-off.

Actually, it is. People complain about the slow traffic in the opposite
direction (although it isn't quite as bad, as the carriageways diverge a
bit).

I've seen a suggestion elsewhere that this is a result of
somebody badly interpreting the relevant rules saying that
gradients less than 10% do not need signs.

They feel that some warning is required, so have chosen the least
gradient that they believe they can have a sign for.

Chris
--
Chris J Dixon Nottingham UK


Plant amazing Acers.

"fred" wrote in message
...

No its the selfish cyclists in their peloton who wouldn't dream of single
filing to let traffic through. And they wonder why motorists hate them.

Actually I think there should be a law that pelotons have to go single
file when in 30mph zones.

I would go further and say that a peleton should be illegal on the public
road, irrespective of speed limit, and that groups of more than n (n being
about 5) cyclists should break apart with a gap of a couple of car-lengths
between one group and the next, to allow cars to "leapfrog" from one group
to the next, rather than having to overtake them all in one go (or not at
all).

I think I'd make it the opposite of your "law" - that a peleton is only
allowed where they are travelling no slower than the speed limit - so
allowed in a 30 zone where no traffic will want to get past them, but banned
if there is traffic that is allowed to go faster than them that will want to
get past.

If they want to ride as a peleton, in cycle race conditions, they should do
that on private roads/tracks where there is no traffic wanting to get past
them. The whole concept of racing on public roads, and the peleton grouping
that goes with it, should be outlawed on roads. All other forms of (motor)
racing, except on temporarily-closed roads, is banned - why should we make
an exception for bikes?

I've no problems with a few friends riding together in a small group,
two-abreast until a car wants to get past them. But large groups that make
it difficult for cars to get past, are socially unacceptable.

On Wednesday, February 13, 2019 at 4:58:16 PM UTC, Dave Plowman (News) wrote:
In article ,
Brian Gaff wrote:
Actually my neighbour had a Metro and boy could that thing move. The
speedo kind of just hit the end and after that it was guesswork. Only
problem with it was that it tended to be full of rust even when new.

As I said - a very optimistic speedo. Some makers today do just the same.
When making one which is within 1% accuracy should be child's play since
they are counting pulses.

--
*The closest I ever got to a 4.0 in school was my blood alcohol content*

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

Years ago when speedometers were mechanically driven I had a Cortina with an automatic box. I had always thought it was very noisy at 70 or so mph so I had a friend trail me one night. THe speedo was under reading byt about 8 mph. I often wondered ift they had fitted the wromng cable

"Jim K.." wrote in message
o.uk...
Still hopefully the same external diameter, otherwise the car would (try
to)
go round in circles.

We call them differentials...

Would a differential iron-out the tendency for two wheels on the same axle
with different diameters to want to steer in one direction, needing constant
counter-steer to correct it?

Maybe it would. Obviously it allows them to rotate at different speeds when
they are turning on different radii of curvature, but would a car that is
going in a straight line tend to keep that line if the tyres were different
sizes?

I *thought* that a spacesaver spare tyre was always (nominally) the same OD
as the wheel that it is replacing, allowing for different amounts of tread
wear, and that it was only the tyre *width* that was narrower. I agree that
one wheel may be a different size to the other, but that is immaterial as
long as the OD of the tyre is the same.

In article , fred
wrote:
On Wednesday, February 13, 2019 at 4:58:16 PM UTC, Dave Plowman (News)
wrote:
In article , Brian Gaff
wrote:
Actually my neighbour had a Metro and boy could that thing move. The
speedo kind of just hit the end and after that it was guesswork. Only
problem with it was that it tended to be full of rust even when new.

As I said - a very optimistic speedo. Some makers today do just the
same. When making one which is within 1% accuracy should be child's
play since they are counting pulses.

-- *The closest I ever got to a 4.0 in school was my blood alcohol
content*

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

Years ago when speedometers were mechanically driven I had a Cortina with
an automatic box. I had always thought it was very noisy at 70 or so mph
so I had a friend trail me one night. THe speedo was under reading byt
about 8 mph. I often wondered ift they had fitted the wromng cable

Ah, so the 100mph I wound my Cortina IV up to on the M4 might have been
even higher.

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

"AnthonyL" wrote in message
...
Back in the day it was an 848cc A35 van, then same size Mini. What a
waste in the days when the black diagonal really meant no speed limit.

It's scary to think that vehicles that were capable of well over 100 mph
could be sharing a lane with vehicles that were physically unable to reach
even 50 or 60, or drivers that were unwilling to drive any faster even if
the vehicle could do so.

At least nowadays just about all vehicles that are allowed to use a motorway
are physically capable of reaching at least 56 mph / 80 km/hr and all cars
capable of doing at least 70, so there's much less spread of speed than
there used to be on unrestricted motorways (or still are on modern German
autobahns *). I suppose on unrestricted roads, drivers are a lot more
disciplined in only entering that lane if they can see that there really
isn't anyone coming up behind them going a lot faster - which is not the
case on your average British motorway where it's common to be doing 70 and
find that someone doing 50 pulls out in front of you without caring.


(*) OK, I know it should be "autobahnen", but my rule is that if we borrow
or steal a foreign word, we have the right to form its plural the English
way ;-)

On 13/02/2019 16:54, Dave Plowman (News) wrote:
In article ,
Brian Gaff wrote:
Actually my neighbour had a Metro and boy could that thing move. The
speedo kind of just hit the end and after that it was guesswork. Only
problem with it was that it tended to be full of rust even when new.

As I said - a very optimistic speedo. Some makers today do just the same.
When making one which is within 1% accuracy should be child's play since
they are counting pulses.


Yes you could do it if the pulses were coming from a laser scanner
pointing at the road so wear and pressure changes in the tyres didn't
have any effect, or you could drag a fifth wheel speedo behind you to
get an accurate speed.

On 13/02/2019 21:39, alan_m wrote:
On 13/02/2019 18:12, Robin wrote:

depends on wheel/tyre of course but I was reckoning on tread going
from 8mm to 2mm on a tyre of around 180mm circumference.


What about different minor variants of the same basic car?Â* It wouldn't
be unusual for them to be fitted with either,say, 16 or 17 inch wheels.
Do the manufactures adjust the calibration for different factory fitted
wheels or do they rely of range they allowed on the speedo readings?

What about the reading within spec with a space-saver wheel on one corner



You aren't supposed to drive with the space saver on the front so that
removes front wheel drive cars from the equation.

They nearly always recommend swapping the wheels so the space saver is
on the rear.

People don't of course because they are too idle.

On 14/02/2019 13:38, NY wrote:
"Jim K.." wrote in message
o.uk...
Still hopefully the same external diameter, otherwise the car would
(try to)
go round in circles.

We call them differentials...

Would a differential iron-out the tendency for two wheels on the same
axle with different diameters to want to steer in one direction, needing
constant counter-steer to correct it?

Maybe it would. Obviously it allows them to rotate at different speeds
when they are turning on different radii of curvature, but would a car
that is going in a straight line tend to keep that line if the tyres
were different sizes?

I *thought* that a spacesaver spare tyre was always (nominally) the same
OD as the wheel that it is replacing, allowing for different amounts of
tread wear, and that it was only the tyre *width* that was narrower. I
agree that one wheel may be a different size to the other, but that is
immaterial as long as the OD of the tyre is the same.

They are frequently smaller all around.
The limit to how small they can make them is the clearance on the brakes.

"dennis@home" wrote in message
...
On 13/02/2019 21:39, alan_m wrote:
On 13/02/2019 18:12, Robin wrote:

depends on wheel/tyre of course but I was reckoning on tread going from
8mm to 2mm on a tyre of around 180mm circumference.


What about different minor variants of the same basic car? It wouldn't
be unusual for them to be fitted with either,say, 16 or 17 inch wheels.
Do the manufactures adjust the calibration for different factory fitted
wheels or do they rely of range they allowed on the speedo readings?

What about the reading within spec with a space-saver wheel on one corner



You aren't supposed to drive with the space saver on the front so that
removes front wheel drive cars from the equation.

They nearly always recommend swapping the wheels so the space saver is on
the rear.

People don't of course because they are too idle.

I've not actually heard of that recommendation, though I can see that it
makes sense. It does take a lot longer, because you have to make two
manoeuvres instead of one:

- spare on back to free up a good tyre
- good tyre on front in place of punctured tyre

Mind you, a lot of the time of changing a wheel is initial stuff like
removing stuff from the boot onto the back seat to lift the boot floor to
get at the spare and the jack.

With modern scissor jacks (which have almost no ground clearance for the
handle to turn without grazing your knuckles, it is a thankless task.

The last time I had to change a wheel was about 6 months ago when I caught
the inside of a tyre (almost brand new) on the edge of the road surface that
stood proud of a rut beside the road, when an oncoming tractor who should
have given way to me bullied his way forward so I had to veer off the road
to avoid a collision. The tyre held up for another half-mile till I got home
and parked, but a few minutes later a neighbour said "do you know you've got
a flat tyre". That was a waste of £40: there was a huge gash in the inside
wall, a *long* way from the tread so no quibble: the tyre was unrepeatable.

"dennis@home" wrote in message
news
I *thought* that a spacesaver spare tyre was always (nominally) the same
OD as the wheel that it is replacing, allowing for different amounts of
tread wear, and that it was only the tyre *width* that was narrower. I
agree that one wheel may be a different size to the other, but that is
immaterial as long as the OD of the tyre is the same.

They are frequently smaller all around.
The limit to how small they can make them is the clearance on the brakes.

And how much the car sags at one corner because one wheel is smaller. When I
can be arsed, I'll go and measure my spare against a full-size wheel. They
look the same OD and the car looks level, without a dip at one corner making
the opposite corner high and hence less downward force on that wheel.

Certainly I've not felt any pulling to one side on the steering, with the
spare on the front or the back - I was amazed at how little it affected the
handling of the car, though I'd be more cautious on cornering and I'd
restrict myself to the 50 mph and 50 miles limit that they always say.

Gone are the days when your spare is fully-interchangeable with the four
running wheels and can be driven as far and as fast as you like without any
limit. I really wish the UK would mandate cars to be designed so they can
accommodate a full-side spare (steel rather than allow wheel, but otherwise
normal tyre) as used to be the case until corner-cutting took over. Cars
always had a recess in the boot floor or else a cage under the boot for the
full size wheel - or on some cars like the Ford Zephyr and some small
Renaults it was under the bonnet. Nowadays the boot doesn't seem any more
capacious but there's allegedly no room for a full size wheel in boot - all
the pain, but with no perceivable gain.

I think even our big Honda CRV has a space-saver spare, and that's got
plenty of space below the boot floor to take a full-height spare.

Car manufacturers say "oh, it's not a problem - put the spare on and drive
to a tyre place". Not at 10 PM on a Sunday when you're about to start on a
long journey. I don't think I've ever in all the years I've been driving had
a puncture that's happened during shop opening hours - it's always late at
night or on a Sunday that I discover it. Until recently it was a minor
nuisance which delays me setting off by 10 mins or so to fit the spare, and
then take the dead tyre in to be repaired at a later date when I'm not in a
rush to be somewhere. Now it's a show-stopper which means waiting till the
following morning to set off after I've been to the garage - hoping that
they actually have the right size in stock and I don't have to wait another
24 hours till they've ordered one in.

On Wed, 13 Feb 2019 21:39:40 +0000, ARW wrote:

The standard of driving on the M1 South of Luton is probably some of the
worst motorway driving I have seen in the UK.

Hum, was down at Milton Keynes and Nottingham last year, thought the
M1 driving was much better than the M6/M61 south of Preston. That's
abit further north I think but the picture of a dragon obscures the
map.

The M1 is mostly "smart motorway" and even without the variable speed
limit in operation everyone one was doing 70 and reasonably well
spaced out. Presumably because some of the VSL gantries also have
ordinary speed cameras bolted on the side...

The M6/M61 is not "smart motorway" and no speed cameras. Any time
near the rush and you'll have cars doing 80+ mph, two car lengths
apart.

The M61 is only 20 miles long, time difference between *average*
speeds of 65 and 75, is a mere 2' 27". Do people really time their
commute so finely? Hitting a couple sets of lights on red instead of
green will add that sort of time...

--
Cheers
Dave.

On 14/02/2019 17:07, NY wrote:
"dennis@home" wrote in message
news
I *thought* that a spacesaver spare tyre was always (nominally) the
same OD as the wheel that it is replacing, allowing for different
amounts of tread wear, and that it was only the tyre *width* that was
narrower. I agree that one wheel may be a different size to the
other, but that is immaterial as long as the OD of the tyre is the same.

They are frequently smaller all around.
The limit to how small they can make them is the clearance on the brakes.

And how much the car sags at one corner because one wheel is smaller.
When I can be arsed, I'll go and measure my spare against a full-size
wheel. They look the same OD and the car looks level, without a dip at
one corner making the opposite corner high and hence less downward force
on that wheel.

Certainly I've not felt any pulling to one side on the steering, with
the spare on the front or the back - I was amazed at how little it
affected the handling of the car, though I'd be more cautious on
cornering and I'd restrict myself to the 50 mph and 50 miles limit that
they always say.

I would check that it doesn't say 50 km/hr.


Gone are the days when your spare is fully-interchangeable with the four
running wheels and can be driven as far and as fast as you like without
any limit. I really wish the UK would mandate cars to be designed so
they can accommodate a full-side spare (steel rather than allow wheel,
but otherwise normal tyre) as used to be the case until corner-cutting
took over. Cars always had a recess in the boot floor or else a cage
under the boot for the full size wheel - or on some cars like the Ford
Zephyr and some small Renaults it was under the bonnet. Nowadays the
boot doesn't seem any more capacious but there's allegedly no room for a
full size wheel in boot - all the pain, but with no perceivable gain.

I think even our big Honda CRV has a space-saver spare, and that's got
plenty of space below the boot floor to take a full-height spare.

Car manufacturers say "oh, it's not a problem - put the spare on and
drive to a tyre place". Not at 10 PM on a Sunday when you're about to
start on a long journey. I don't think I've ever in all the years I've
been driving had a puncture that's happened during shop opening hours -
it's always late at night or on a Sunday that I discover it. Until
recently it was a minor nuisance which delays me setting off by 10 mins
or so to fit the spare, and then take the dead tyre in to be repaired at
a later date when I'm not in a rush to be somewhere. Now it's a
show-stopper which means waiting till the following morning to set off
after I've been to the garage - hoping that they actually have the right
size in stock and I don't have to wait another 24 hours till they've
ordered one in.

Think yourself lucky, they don't do a space saver in my car.
But as its a motability car I might just ignore the flat and drive to a
tyre place if its close or call them out if it isn't.

I suppose I could try the junk in the can first if I can get to the tyre
without getting run down.

The last puncture I had I drove a couple of miles on the M^ roadworks to
avoid stopping on a live lane, its fine as long as you can do at least
50 to keep the tyre up by centripetal forces.
Then I had the RAC come and change it while I watched from behind the
barriers.

In message ,
writes
On Wednesday, 13 February 2019 12:27:03 UTC, wrote:

Overheard someone talking to someone that was going to supply her a
temporary vehicle. She was very concerned that the car should be at
least a 2.0 as she intends to dive on the motorway.

I assume they offered a beemer, because she said

€œI dont know anything about BMWs I drive a Jaguar.
I dont know if they can be driven on the motorway.€�


How the other half lives! I used to take my 1.0 Metros from London
to Preston & back on the motorway on a regular basis (leaving Jaguars
and BMs eating my lead!)

Luxury! I used to do long journeys in a thing with a wooden floor that
topped out at 52mph. Eventually.

Just so! 1956 series 2 Morgan 4/4. Tongue and groove timber floor.
Passenger used to get their calves sprayed if you ventured into a
puddle.

--
Tim Lamb

"dennis@home" wrote in message
...
The last puncture I had I drove a couple of miles on the M^ roadworks to
avoid stopping on a live lane, its fine as long as you can do at least 50
to keep the tyre up by centripetal forces.
Then I had the RAC come and change it while I watched from behind the
barriers.

So far I've been lucky and never had a puncture when I've been on a
motorway. Changing a nearside wheel at least gives you a bit of protection
from passing traffic, but I think I might break with a habit of a lifetime
and call out RAC for one on the offside. The only time I ever needed to call
them out for a puncture was when I couldn't unscrew the wire basket that
held the spare under the boot floor because the thread had seized up. It
took the RAC man about half an hour with applications of WD40, blowlamp
(shielded from tyre) and a lot of cursing to get it free. It would have been
easy if the bolt had had a proper hexagonal wheelnut head, but it was a
circular head with a single U-shaped depression in which you were supposed
to insert the flattened end of the wheelbrace - a really useless cack-handed
design which meant that neither he nor I could get any purchase on the bolt
to turn it.

About the only time I've broken down on a motorway was when the fan belt
failed - and luckily it was only about a mile to the junction where I'd
planned to come off anyway, and only another two miles to a garage where I
know I could wait away from the traffic. I just had to allow for the
steering being a *lot* heavier because the "fan belt" drives the power
steering. Inevitably as with so many thing on a modern car, the RAC man
couldn't fit a new belt (it's a major job even for a garage to do) so he
just had to tow me home and I popped it round to my local garage afterwards.

I wouldn't have liked to wait half an hour in the cold and rain outside my
car on the motorway - I judged that I'd have plenty of battery to drive the
car (including lights) without an alternator without having to stop
immediately.

Sadly the garage didn't notice *why* the fanbelt had failed: one of the
pulleys had a distorted flange. So after shelling out about £400 for part
and labour, the new belt failed a few hundred miles later - and the garage
denied all liability for parts and labour, even when faced with a statement
from the main-dealer garage where I took my car for the second belt. So I
stopped using them after that, and mentioned my experience to as many locals
as possible.

Dave Plowman (News) brought next idea :
Quite. Although even eddy current speedos could be far more accurate than
that spec.

Then there were chronometric ones. You'd laugh at a clock which couldn't
better 10% accuracy even in the 19th century.

Yep, the calibrated speedo in traffic cars.

"Harry Bloomfield" wrote in message
...
Dave Plowman (News) brought next idea :
Quite. Although even eddy current speedos could be far more accurate than
that spec.

Then there were chronometric ones. You'd laugh at a clock which couldn't
better 10% accuracy even in the 19th century.

Yep, the calibrated speedo in traffic cars.

Do traffic cars still use those in preference to GPS? I presume nowadays if
they do measure wheel rotations, everything is electronic, with no moving
parts other than the object that rotates at (a proportion of) wheel speed,
but now sensed by a Hall effect sensor and then rate of pulses (speed)
determined electronically - so there's no spring in the gauge to need to be
recalibrated as it loses its springiness. I wonder if they are recalibrated
periodically as a car's tyres wear down.

I remember in the 1970s we were staying on a caravan site and the guy in the
next caravan was a traffic policeman who described how they trained their
pursuit drivers to drive at speed - on "live" roads with real traffic, with
a "hare" driver (inevitably, in a Jag Mark II or S-type) that that "hound"
had to follow. He said that their "best hare" was a tiny lass whose feet
barely reached the pedals and who looked as if a strong wind would blow her
away, but who was almost impossible for even the best pursuit drivers to
keep up with as she weaved through traffic. Wouldn't be allowed nowadays.
H&S and all that. Reminds me of that cracking episode "Stoppo Driver" of The
Sweeney.