Does anyone out there have any experience of wireless tyre pressure 
monitoring devices - the sort which have special valves containing a sensor, 
and a central display with LEDs and a bleeper and report status?

Yesterday, I wrote off an otherwise perfectly good 225/45x17 tyre because I 
had apparently been driving it flat for a while without noticing.

In days of yore I could always tell by the seat of my pants if a tyre was a 
bit flat. But many modern cars are grossly over-tyred, with very wide low 
profile tyres which *look* flat when they're not, and don't really *feel* 
any different when they are.

At £100 a throw, you don't have to write off too many tyres before a 
monitoring system would be cheaper.

Any comments or recommendations?

TIA.
-- 
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly 
monitored..
Messages sent to it may not be read for several weeks. PLEASE REPLY TO 
NEWSGROUP!

Roger Mills wrote:
> Does anyone out there have any experience of wireless tyre pressure
> monitoring devices - the sort which have special valves containing a
> sensor, and a central display with LEDs and a bleeper and report
> status?
> Yesterday, I wrote off an otherwise perfectly good 225/45x17 tyre
> because I had apparently been driving it flat for a while without
> noticing.
> In days of yore I could always tell by the seat of my pants if a tyre
> was a bit flat. But many modern cars are grossly over-tyred, with
> very wide low profile tyres which *look* flat when they're not, and
> don't really *feel* any different when they are.
>
> At £100 a throw, you don't have to write off too many tyres before a
> monitoring system would be cheaper.
>
> Any comments or recommendations?
>
How about manuall checking your tyre pressures weekly, at the same time as 
you make all your other routine checks?

You do make routine checks don't you?

On Thu, 11 Sep 2008 10:31:08 +0100, "Brimstone"
 wrote:

>Roger Mills wrote:
>> Does anyone out there have any experience of wireless tyre pressure
>> monitoring devices - the sort which have special valves containing a
>> sensor, and a central display with LEDs and a bleeper and report
>> status?
>> Yesterday, I wrote off an otherwise perfectly good 225/45x17 tyre
>> because I had apparently been driving it flat for a while without
>> noticing.
>> In days of yore I could always tell by the seat of my pants if a tyre
>> was a bit flat. But many modern cars are grossly over-tyred, with
>> very wide low profile tyres which *look* flat when they're not, and
>> don't really *feel* any different when they are.
>>
>> At £100 a throw, you don't have to write off too many tyres before a
>> monitoring system would be cheaper.
>>
>> Any comments or recommendations?
>>
>How about manuall checking your tyre pressures weekly, at the same time as 
>you make all your other routine checks?
>
>You do make routine checks don't you? 
>

Must be "very" low profile if you can't tell the difference when it's
flat .

In article , Brimstone says...

> > Any comments or recommendations?
> >
> How about manuall checking your tyre pressures weekly, at the same time as 
> you make all your other routine checks?
> 
> You do make routine checks don't you? 
> 
Don't be daft.


-- 
Conor

I only please one person per day. Today is not your day. Tomorrow isn't 
looking good either. - Scott Adams

Roger Mills wrote:
> Does anyone out there have any experience of wireless tyre pressure
> monitoring devices - the sort which have special valves containing a
> sensor, and a central display with LEDs and a bleeper and report
> status?
> Yesterday, I wrote off an otherwise perfectly good 225/45x17 tyre
> because I had apparently been driving it flat for a while without
> noticing.
> In days of yore I could always tell by the seat of my pants if a tyre
> was a bit flat. But many modern cars are grossly over-tyred, with
> very wide low profile tyres which *look* flat when they're not, and
> don't really *feel* any different when they are.
>
> At £100 a throw, you don't have to write off too many tyres before a
> monitoring system would be cheaper.
>
> Any comments or recommendations?
>
Check the pressures yourself once a week?

Mike P

In uk.d-i-y NOSPAMnet@gmail.com wrote:
> On Thu, 11 Sep 2008 10:31:08 +0100, "Brimstone"
>  wrote:
> 
> >Roger Mills wrote:
> >> Does anyone out there have any experience of wireless tyre pressure
> >> monitoring devices - the sort which have special valves containing a
> >> sensor, and a central display with LEDs and a bleeper and report
> >> status?
> >> Yesterday, I wrote off an otherwise perfectly good 225/45x17 tyre
> >> because I had apparently been driving it flat for a while without
> >> noticing.
> >> In days of yore I could always tell by the seat of my pants if a tyre
> >> was a bit flat. But many modern cars are grossly over-tyred, with
> >> very wide low profile tyres which *look* flat when they're not, and
> >> don't really *feel* any different when they are.
> >>
> >> At £100 a throw, you don't have to write off too many tyres before a
> >> monitoring system would be cheaper.
> >>
> >> Any comments or recommendations?
> >>
> >How about manuall checking your tyre pressures weekly, at the same time as 
> >you make all your other routine checks?
> >
> >You do make routine checks don't you? 
> >
> 
> Must be "very" low profile if you can't tell the difference when it's
> flat .

Depends on the car, a flat at the rear of a 'proper' Citroën with LHM
suspension is really quite difficult to detect unless/until you take
some corners fast.

-- 
Chris Green

tinnews@isbd.co.uk wrote:
> In uk.d-i-y NOSPAMnet@gmail.com wrote:
>> On Thu, 11 Sep 2008 10:31:08 +0100, "Brimstone"
>>  wrote:
>>
>>> Roger Mills wrote:
>>>> Does anyone out there have any experience of wireless tyre pressure
>>>> monitoring devices - the sort which have special valves containing
>>>> a sensor, and a central display with LEDs and a bleeper and report
>>>> status?
>>>> Yesterday, I wrote off an otherwise perfectly good 225/45x17 tyre
>>>> because I had apparently been driving it flat for a while without
>>>> noticing.
>>>> In days of yore I could always tell by the seat of my pants if a
>>>> tyre was a bit flat. But many modern cars are grossly over-tyred,
>>>> with very wide low profile tyres which *look* flat when they're
>>>> not, and don't really *feel* any different when they are.
>>>>
>>>> At £100 a throw, you don't have to write off too many tyres before
>>>> a monitoring system would be cheaper.
>>>>
>>>> Any comments or recommendations?
>>>>
>>> How about manuall checking your tyre pressures weekly, at the same
>>> time as you make all your other routine checks?
>>>
>>> You do make routine checks don't you?
>>>
>>
>> Must be "very" low profile if you can't tell the difference when it's
>> flat .
>
> Depends on the car, a flat at the rear of a 'proper' Citroën with LHM
> suspension is really quite difficult to detect unless/until you take
> some corners fast.

Yes, when I had a flat on my Xantia, on the motorway at maybe slightly more 
than 70, I didn't notice until I smelt burning rubber :-) I'm old enough to 
remember the Citroen GS ad where they blew a tyre out when it was in between 
two trucks at speed :-)

Mike P

Roger Mills wrote:
> Does anyone out there have any experience of wireless tyre pressure 
> monitoring devices - the sort which have special valves containing a sensor, 
> and a central display with LEDs and a bleeper and report status?
> 
> Yesterday, I wrote off an otherwise perfectly good 225/45x17 tyre because I 
> had apparently been driving it flat for a while without noticing.
> 
> In days of yore I could always tell by the seat of my pants if a tyre was a 
> bit flat. But many modern cars are grossly over-tyred, with very wide low 
> profile tyres which *look* flat when they're not, and don't really *feel* 
> any different when they are.
> 
> At �100 a throw, you don't have to write off too many tyres before a 
> monitoring system would be cheaper.
> 
> Any comments or recommendations?
> 
> TIA.

Some of the 'check it' comments might be applicable to the OP (and to 
me!) - after all, he says he drove for a while in that state. But such 
checking really doesn't address the journey on which the problem starts 
to manifest itself.

There are a great many multi-axle and multi-wheel-per-axle vehicles - I 
don't have the experience, but I can't believe a low tyre would be that 
obvious.

I think that pressure sensors (of whatever sort are implemented) are 
potentially a major contribution to road safety. (Hmmm, now where did I 
here that before?)

-- 
Rod

Hypothyroidism is a seriously debilitating condition with an insidious 
onset.
Although common it frequently goes undiagnosed.
<www.thyromind.info> <www.thyroiduk.org> <www.altsupportthyroid.org>

Rod wrote:
> I think that pressure sensors (of whatever sort are implemented) are 
> potentially a major contribution to road safety. (Hmmm, now where did I 
> here that before?)
> 
Blooming spelling checkers - please correct my typing *then* my spelling 
- of course that should be 'hear'!

-- 
Rod

Following up to Mike P  

> Check the pressures yourself once a week?

tyres dont  always wait a week to go soft and a soft tyre doesnt notice on
a modern car till probably too late to save it. How about treating the
query as other than an opportunity for sarcasm, everyone.
-- 
M..........
google-groups killfiled (known posters whitelisted)
Remove the obvious  to email

M............ wrote:
> Following up to Mike P
>
>> Check the pressures yourself once a week?
>
> tyres dont  always wait a week to go soft and a soft tyre doesnt
> notice on a modern car till probably too late to save it.

Every modern car I've driven, bar the Xantia, I find it easy to tell when a 
tyre is soft. Up until recently, over the last 15 years or so I've always 
had access to, and used company pool cars. They don't get looked after as 
they should do and within a couple of miles I can tell whether the tyres are 
soft or not.  I seemed to be the only one who bothered to ever check the 
tyres and oil between services in them

Mike P

"Mike P"  wrote in message 
news:6isaioF9qt6U1@mid.individual.net...


> Yes, when I had a flat on my Xantia, on the motorway at maybe slightly 
> more than 70, I didn't notice until I smelt burning rubber :-) I'm old 
> enough to remember the Citroen GS ad where they blew a tyre out when it 
> was in between two trucks at speed :-)

That's the easy option, centrifugal force keeps the tyre round even without 
the air when you are driving fast.
It would have been fun to see them do it on a curved bit.

In an earlier contribution to this discussion,
Brimstone   wrote:

> Roger Mills wrote:
>> Does anyone out there have any experience of wireless tyre pressure
>> monitoring devices - the sort which have special valves containing a
>> sensor, and a central display with LEDs and a bleeper and report
>> status?
>>
>> Any comments or recommendations?
>>
> How about manuall checking your tyre pressures weekly, at the same
> time as you make all your other routine checks?
>
> You do make routine checks don't you?

Yes, I do make frequent visual checks - and occasional checks with a 
pressure gauge (plus under-bonnet checks), but - as others have pointed 
out - if you pick up a nail and a tyre starts to deflate while on a journey, 
weekly checks ain't going to help.

Do you have anything *useful* to contribute?
-- 
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

"Brimstone"  wrote in message 
news:HI6dnUWGpMj9eFXVnZ2dnUVZ8hydnZ2d@bt.com...
> Roger Mills wrote:
>> Does anyone out there have any experience of wireless tyre 
>> pressure
>> monitoring devices - the sort which have special valves 
>> containing a
>> sensor, and a central display with LEDs and a bleeper and 
>> report
>> status?
>> Yesterday, I wrote off an otherwise perfectly good 225/45x17 
>> tyre
>> because I had apparently been driving it flat for a while 
>> without
>> noticing.
>> In days of yore I could always tell by the seat of my pants if 
>> a tyre
>> was a bit flat. But many modern cars are grossly over-tyred, 
>> with
>> very wide low profile tyres which *look* flat when they're 
>> not, and
>> don't really *feel* any different when they are.
>>
>> At £100 a throw, you don't have to write off too many tyres 
>> before a
>> monitoring system would be cheaper.
>>
>> Any comments or recommendations?
>>
> How about manuall checking your tyre pressures weekly, at the 
> same time as you make all your other routine checks?
>
> You do make routine checks don't you?

Unfortunately routine checks don't cover all eventualities.
Does anyone visually check all 4 tyres every time they use their 
car?

I can sympathise with the OP as I wrote off a 255x40x17 tyre in a 
similar way. At low speeds, on a straight road, it's very 
difficult to detect a flat low profile rear tyre.

In my case it was the n/s rear tyre. Fine in the morning. Jumped 
in and drove about 300 yds straight up the road on my way home. 
Realised something was not quite right, so stopped and found the 
flat tyre.
Changed it for the spare, but the damage was done. With the 
weight of the car on the fold in the tyre, the carcass had 
started to delaminate.

The only consolation, if you can call it that, is that the tyre 
would have been scrap anyway, as a the puncture which had caused 
it to deflate during the day was an unrepairable one on the 
shoulder.

I checked and decided against the option of tyre monitors. 
Aftermarket ones rely on wireless dust caps, which are too easily 
nicked. I just check the tyres a bit more frequently than I did 
before.
Mike.

"Mike P"  wrote in message 
news:6isdptFa1k9U1@mid.individual.net...
> M............ wrote:
>> Following up to Mike P
>>
>>> Check the pressures yourself once a week?
>>
>> tyres dont  always wait a week to go soft and a soft tyre 
>> doesnt
>> notice on a modern car till probably too late to save it.
>
> Every modern car I've driven, bar the Xantia, I find it easy to 
> tell when a tyre is soft. Up until recently, over the last 15 
> years or so I've always had access to, and used company pool 
> cars. They don't get looked after as they should do and within 
> a couple of miles I can tell whether the tyres are soft or not.

A couple of miles!
A low profile tyre can be ruined in a few hundred yards, as I 
found out for myself just over a year ago.

I seemed to be the only one who bothered to ever check the
> tyres and oil between services in them

Don't kid yourself. I keep a close eye on tyre pressures. 
Checking at least once a week, and on a run would expect to 
detect a loss of as little as 2-3 lbs, simply from how the car 
handles. However it can be difficult to detect a flat low profile 
tyre at low speeds.
Mike.

Mike G wrote:
> "Mike P"  wrote in message
> news:6isdptFa1k9U1@mid.individual.net...
>> M............ wrote:
>>> Following up to Mike P
>>>
>>>> Check the pressures yourself once a week?
>>>
>>> tyres dont  always wait a week to go soft and a soft tyre
>>> doesnt
>>> notice on a modern car till probably too late to save it.
>>
>> Every modern car I've driven, bar the Xantia, I find it easy to
>> tell when a tyre is soft. Up until recently, over the last 15
>> years or so I've always had access to, and used company pool
>> cars. They don't get looked after as they should do and within
>> a couple of miles I can tell whether the tyres are soft or not.
>
> A couple of miles!

Yes, if it's "soft" if it's flat then much quicker.

> A low profile tyre can be ruined in a few hundred yards, as I
> found out for myself just over a year ago.
>
> I seemed to be the only one who bothered to ever check the
>> tyres and oil between services in them
>
> Don't kid yourself.

I wasn't inferring that no one else does, I just meant the other users of 
the pool cars I used to use.

> I keep a close eye on tyre pressures.
> Checking at least once a week, and on a run would expect to
> detect a loss of as little as 2-3 lbs, simply from how the car
> handles. However it can be difficult to detect a flat low profile
> tyre at low speeds.

I don't see how it can be with the amount of uneven surfaces and holes that 
will make it obvious something isn't right ;-)

Mike P

"Mike P"  wrote in message 
news:6ish92Farh5U1@mid.individual.net...
> Mike G wrote:
>> "Mike P"  wrote in message
>> news:6isdptFa1k9U1@mid.individual.net...
>>> M............ wrote:
>>>> Following up to Mike P
>>>>
>>>>> Check the pressures yourself once a week?
>>>>
>>>> tyres dont  always wait a week to go soft and a soft tyre
>>>> doesnt
>>>> notice on a modern car till probably too late to save it.
>>>
>>> Every modern car I've driven, bar the Xantia, I find it easy 
>>> to
>>> tell when a tyre is soft. Up until recently, over the last 15
>>> years or so I've always had access to, and used company pool
>>> cars. They don't get looked after as they should do and 
>>> within
>>> a couple of miles I can tell whether the tyres are soft or 
>>> not.
>>
>> A couple of miles!
>
> Yes, if it's "soft" if it's flat then much quicker.
>
>> A low profile tyre can be ruined in a few hundred yards, as I
>> found out for myself just over a year ago.
>>
>> I seemed to be the only one who bothered to ever check the
>>> tyres and oil between services in them
>>
>> Don't kid yourself.
>
> I wasn't inferring that no one else does, I just meant the 
> other users of the pool cars I used to use.
>
>> I keep a close eye on tyre pressures.
>> Checking at least once a week, and on a run would expect to
>> detect a loss of as little as 2-3 lbs, simply from how the car
>> handles. However it can be difficult to detect a flat low 
>> profile
>> tyre at low speeds.
>
> I don't see how it can be with the amount of uneven surfaces 
> and holes that will make it obvious something isn't right ;-)

I only drove about 300 yds at a fairly low speed.. A flat 
concrete road on the trading estate where I work, which was 
enough to start delaminating a 255x40x17 tyre.

Because it was low profile, the rim of the wheel was running on 
the fold of the tyre.

With a normal size flat tyre the fold is clear of the rim. The 
fold is less severe, and not having the weight of the car on it, 
is more likely to survive for a short period without damage.
Mike.

"Rod"  wrote in message 
news:6isc9iF9o9rU2@mid.individual.net...
> Rod wrote:
>> I think that pressure sensors (of whatever sort are implemented) are 
>> potentially a major contribution to road safety. (Hmmm, now where did I 
>> here that before?)
>>
> Blooming spelling checkers - please correct my typing *then* my spelling - 
> of course that should be 'hear'!
>
> -- 
> Rod

As an aside, have you ever told another driver that one of their tyres looks 
soft. I have and it is normally met with apathy of abuse. Yesterday I told a 
young woman and at least she giggled.

I just cannot image how badly some cars must handle with a soft tyre.

Soft tyres and failed brake lights seem to be ignored by many.

"Mike G"  gurgled happily, sounding much like they
were saying:

> I only drove about 300 yds at a fairly low speed.. A flat concrete road
> on the trading estate where I work, which was enough to start
> delaminating a 255x40x17 tyre.
> 
> Because it was low profile, the rim of the wheel was running on the fold
> of the tyre.
>
> With a normal size flat tyre the fold is clear of the rim. The 
> fold is less severe, and not having the weight of the car on it, 
> is more likely to survive for a short period without damage.

Nothing to do with the profile of the tyre - if the tyre's flat, that's 
how the weight on that corner is always going to be borne. Unless, of 
course, your car has so little suspension travel that the difference in 
sidewall height between a 40 and a 60 profile tyre is significant...

No tyre will stand up to that. They're just not designed to, even run-
flats will be damaged beyond repair.

You may have a point with the "fold is less severe" - but the weight WILL 
still be being borne by the rim on the folded sidewall.

John wrote:
> "Rod"  wrote in message 
> news:6isc9iF9o9rU2@mid.individual.net...
>> Rod wrote:
>>> I think that pressure sensors (of whatever sort are implemented) are 
>>> potentially a major contribution to road safety. (Hmmm, now where did I 
>>> here that before?)
>>>
>> Blooming spelling checkers - please correct my typing *then* my spelling - 
>> of course that should be 'hear'!
>>
>> -- 
>> Rod
> 
> As an aside, have you ever told another driver that one of their tyres looks 
> soft. I have and it is normally met with apathy of abuse. Yesterday I told a 
> young woman and at least she giggled.
> 
> I just cannot image how badly some cars must handle with a soft tyre.
> 
> Soft tyres and failed brake lights seem to be ignored by many. 
> 
> 
Yes. It is. They do. They are. :-)

Sometimes the difference in shape would be obvious to someone walking 
past the vehicle.

Soemwhat frightening when you see them that bad at 90+ on a busy motorway.

-- 
Rod

Hypothyroidism is a seriously debilitating condition with an insidious 
onset.
Although common it frequently goes undiagnosed.
<www.thyromind.info> <www.thyroiduk.org> <www.altsupportthyroid.org>

"Adrian"  wrote in message 
news:6isk0pFbc5oU2@mid.individual.net...
> "Mike G"  gurgled happily, sounding much 
> like they
> were saying:
>
>> I only drove about 300 yds at a fairly low speed.. A flat 
>> concrete road
>> on the trading estate where I work, which was enough to start
>> delaminating a 255x40x17 tyre.
>>
>> Because it was low profile, the rim of the wheel was running 
>> on the fold
>> of the tyre.
>>
>> With a normal size flat tyre the fold is clear of the rim. The
>> fold is less severe, and not having the weight of the car on 
>> it,
>> is more likely to survive for a short period without damage.
>
> Nothing to do with the profile of the tyre - if the tyre's 
> flat, that's
> how the weight on that corner is always going to be borne.

You're wrong. The hight of the tyre from the rim makes a 
significant difference. Regardless of profile, when the tyre is 
flat, the rim drops straight down, and the sidewalls flex away. 
In the case of a 60 plus profile, the rim will in effect run on 
the part of the tyre nearest the rim, and the tread of the tyre, 
with much of the sidewall outside the actual contact points 
Because there is less depth of sidewall on a low profile tyre, 
the rim can actually run on the folded sidewall itself, which 
leads to rapid delamination. The sidewall just can't take such 
severe creasing without damage.

Unless, of
> course, your car has so little suspension travel that the 
> difference in
> sidewall height between a 40 and a 60 profile tyre is 
> significant...

Suspension travel has nothing to do with it.
Mike.

"Mike G"  gurgled happily, sounding much like they
were saying:

>>> Because it was low profile, the rim of the wheel was running on the
>>> fold of the tyre.
>>>
>>> With a normal size flat tyre the fold is clear of the rim. The fold is
>>> less severe, and not having the weight of the car on it,
>>> is more likely to survive for a short period without damage.

>> Nothing to do with the profile of the tyre - if the tyre's flat, that's
>> how the weight on that corner is always going to be borne.

> You're wrong. The hight of the tyre from the rim makes a significant
> difference. Regardless of profile, when the tyre is flat, the rim drops
> straight down, and the sidewalls flex away. In the case of a 60 plus
> profile, the rim will in effect run on the part of the tyre nearest the
> rim, and the tread of the tyre, with much of the sidewall outside the
> actual contact points Because there is less depth of sidewall on a low
> profile tyre, the rim can actually run on the folded sidewall itself

I think you're confusing any difference between tread width and rim width 
with the height of the sidewall.

The ONLY difference between a flat 60 and a flat 40 profile tyre, of the 
same tread width on the same width rim, is going to be the amount of 
sidewall hanging out the side. Unless you're thinking the bead somehow 
miraculously comes unseated?

"John"  wrote:
>
>As an aside, have you ever told another driver that one of their tyres looks 
>soft. I have and it is normally met with apathy or abuse. 


My experience too.  

I have stopped telling people for fear of their reaction.

Adrian wrote:
> "Mike G"  gurgled happily, sounding much like they
> were saying:
> 
>>>> Because it was low profile, the rim of the wheel was running on the
>>>> fold of the tyre.
>>>>
>>>> With a normal size flat tyre the fold is clear of the rim. The fold is
>>>> less severe, and not having the weight of the car on it,
>>>> is more likely to survive for a short period without damage.
> 
>>> Nothing to do with the profile of the tyre - if the tyre's flat, that's
>>> how the weight on that corner is always going to be borne.
> 
>> You're wrong. The hight of the tyre from the rim makes a significant
>> difference. Regardless of profile, when the tyre is flat, the rim drops
>> straight down, and the sidewalls flex away. In the case of a 60 plus
>> profile, the rim will in effect run on the part of the tyre nearest the
>> rim, and the tread of the tyre, with much of the sidewall outside the
>> actual contact points Because there is less depth of sidewall on a low
>> profile tyre, the rim can actually run on the folded sidewall itself
> 
> I think you're confusing any difference between tread width and rim width 
> with the height of the sidewall.
> 
> The ONLY difference between a flat 60 and a flat 40 profile tyre, of the 
> same tread width on the same width rim, is going to be the amount of 
> sidewall hanging out the side. Unless you're thinking the bead somehow 
> miraculously comes unseated?
I think Mike is thinking that with more sidewall the bend radius is less 
severe, so less stressful, which I'd say is correct. However, I reckon 
running on the sidewall regardless of the bend severity will quickly 
knacker the tyre.

>>>
>>> Any comments or recommendations?
>>>
>>How about manuall checking your tyre pressures weekly, at the same time as
>>you make all your other routine checks?
>>
>>You do make routine checks don't you?
>>
>
> Must be "very" low profile if you can't tell the difference when it's
> flat .



The shower of sparks from the rims should be a good clue !!
Brad

Roger Mills coughed up some electrons that declared:

> Does anyone out there have any experience of wireless tyre pressure
> monitoring devices - the sort which have special valves containing a
> sensor, and a central display with LEDs and a bleeper and report status?
> 
> Yesterday, I wrote off an otherwise perfectly good 225/45x17 tyre because
> I had apparently been driving it flat for a while without noticing.
> 
> In days of yore I could always tell by the seat of my pants if a tyre was
> a bit flat. But many modern cars are grossly over-tyred, with very wide
> low profile tyres which *look* flat when they're not, and don't really
> *feel* any different when they are.
> 
> At £100 a throw, you don't have to write off too many tyres before a
> monitoring system would be cheaper.
> 
> Any comments or recommendations?
> 
> TIA.

The difficulty comes with mounting something with a bit of electronics and a
battery as an aftermarket valve-stalk attachment (eg think of the wheel
balance and the forces on the stalk doing 70 down the M1 with your R14
wheels or whatever). It can be done for large trucks, but everything's a
bit bigger and slower than for a car, so the relative problems are
lessened.

Lots of solutions exist as a manufacturing option where they get to mount
stuff inside the wheel.

My advice is to get the easiest to use tyre gauge, keep it in the glove box
and use it once per week or fortnight when you check your washer water or
whatever.

Halfords are selling a digital one branded Michelin which I've got
(previously having use the old fashioned but ever reliable mechanical
ones). Seems quite good and just a little bit quicker, little bit easier
which is what you want for a boring routine job.

Cheers

Tim

In message , Mike G 
 writes
>I checked and decided against the option of tyre monitors. Aftermarket 
>ones rely on wireless dust caps, which are too easily nicked.
You can get sensors integrated into the valve stem that sit inside the 
tyre and you can buy sensors that mount around the centre of the rim 
with a steel band (bit like a big hose clip) but they cost a bit more.

Remember to tell the tyre fitters that you have the system as the 
sensors have a nasty habit of ending up in the bin or smashed.

These look similar to the systems fitted by some car manufacturers;

http://www.ambromley.co.uk/tyre-pressure-monitor.html

No connection to the company just the first Google hit that matched what 
I was looking for.
>I just check the tyres a bit more frequently than I did before.
>Mike.

-- 
Clint Sharp

BRAD wrote:
>>>> Any comments or recommendations?
>>>>
>>> How about manuall checking your tyre pressures weekly, at the same time as
>>> you make all your other routine checks?
>>>
>>> You do make routine checks don't you?
>>>
>> Must be "very" low profile if you can't tell the difference when it's
>> flat .
> 
> 
> 
> The shower of sparks from the rims should be a good clue !!
> Brad 
> 
I did manage to drive a Astra est for 5 miles or so round country roads 
and I could not make out what was causing a increase in road noise,the 
car handled fine that was my first ever puncture and it continued to run 
on the rubber rather than the wheel rim, when it was repaired the 
puncture was caused by a horse shoe that went right through the tyre 
much to the amusement of the kwikfit fitter

-- 
Kevin R
Reply address works

Roger Mills wrote:
> In an earlier contribution to this discussion,
> Brimstone   wrote:
> 
>> Roger Mills wrote:
>>> Does anyone out there have any experience of wireless tyre pressure
>>> monitoring devices - the sort which have special valves containing a
>>> sensor, and a central display with LEDs and a bleeper and report
>>> status?
>>>
>>> Any comments or recommendations?
>>>
>> How about manuall checking your tyre pressures weekly, at the same
>> time as you make all your other routine checks?
>>
>> You do make routine checks don't you?
> 
> Yes, I do make frequent visual checks - and occasional checks with a 
> pressure gauge (plus under-bonnet checks), but - as others have pointed 
> out - if you pick up a nail and a tyre starts to deflate while on a journey, 
> weekly checks ain't going to help.
> 

Renault fit them to several cars, kwikfit sometimes forget and rip the 
heads off them, as these are £30 ish each it pleases the manager no end 
as it come out of his profits, but you do have to tell the computer 
which sensor is on which wheel somehow
-- 
Kevin R
Reply address works

In message , BRAD 
 writes
>The shower of sparks from the rims should be a good clue !!
>Brad
You don't get a shower of sparks from and alloy wheel. You might from a 
shredded steel reinforced tyre.
>
>

-- 
Clint Sharp

"Kevin"  wrote in message 
news:pLcyk.3135$t_1.633@newsfe30.ams2...
> BRAD wrote:
>>>>> Any comments or recommendations?
>>>>>
>>>> How about manuall checking your tyre pressures weekly, at the same time 
>>>> as
>>>> you make all your other routine checks?
>>>>
>>>> You do make routine checks don't you?
>>>>
>>> Must be "very" low profile if you can't tell the difference when it's
>>> flat .
>>
>>
>>
>> The shower of sparks from the rims should be a good clue !!
>> Brad
> I did manage to drive a Astra est for 5 miles or so round country roads 
> and I could not make out what was causing a increase in road noise,the car 
> handled fine that was my first ever puncture and it continued to run on 
> the rubber rather than the wheel rim, when it was repaired the puncture 
> was caused by a horse shoe that went right through the tyre much to the 
> amusement of the kwikfit fitter
>
> -- 

Was the horse hurt?

"Chris Bartram"  wrote in message 
news:1221146142.8439.0@proxy01.news.clara.net...
> Adrian wrote:
>> "Mike G"  gurgled happily, sounding much 
>> like they
>> were saying:
>>
>>>>> Because it was low profile, the rim of the wheel was 
>>>>> running on the
>>>>> fold of the tyre.
>>>>>
>>>>> With a normal size flat tyre the fold is clear of the rim. 
>>>>> The fold is
>>>>> less severe, and not having the weight of the car on it,
>>>>> is more likely to survive for a short period without 
>>>>> damage.
>>
>>>> Nothing to do with the profile of the tyre - if the tyre's 
>>>> flat, that's
>>>> how the weight on that corner is always going to be borne.
>>
>>> You're wrong. The hight of the tyre from the rim makes a 
>>> significant
>>> difference. Regardless of profile, when the tyre is flat, the 
>>> rim drops
>>> straight down, and the sidewalls flex away. In the case of a 
>>> 60 plus
>>> profile, the rim will in effect run on the part of the tyre 
>>> nearest the
>>> rim, and the tread of the tyre, with much of the sidewall 
>>> outside the
>>> actual contact points Because there is less depth of sidewall 
>>> on a low
>>> profile tyre, the rim can actually run on the folded sidewall 
>>> itself
>>
>> I think you're confusing any difference between tread width 
>> and rim width with the height of the sidewall.
>>
>> The ONLY difference between a flat 60 and a flat 40 profile 
>> tyre, of the same tread width on the same width rim, is going 
>> to be the amount of sidewall hanging out the side. Unless 
>> you're thinking the bead somehow miraculously comes unseated?
> I think Mike is thinking that with more sidewall the bend 
> radius is less severe, so less stressful, which I'd say is 
> correct. However, I reckon running on the sidewall regardless 
> of the bend severity will quickly knacker the tyre.

IME a 60 plus profile tyre can survive running a short distance 
when it's flat. The 255x40x17 tyre on a 9.5" rim on my car was 
knackered after less than a quarter of a mile at low speed. 
20-25mph.
Mike.

"Mike G"  gurgled happily, sounding much like they
were saying:

> IME a 60 plus profile tyre can survive running a short distance when
> it's flat.

I once killed an 80-profile in a few hundred yards, after coming back to 
the car in the office car park - with no spare... K-F were just around 
the corner, but... nope. Deader than a dead thing.

The key is _totally_ flat, rather than just soft.

Hawk aye the noo wrote:
> "Kevin"  wrote in message 
> news:pLcyk.3135$t_1.633@newsfe30.ams2...
>> BRAD wrote:
>>>>>> Any comments or recommendations?
>>>>>>
>>>>> How about manuall checking your tyre pressures weekly, at the same time 
>>>>> as
>>>>> you make all your other routine checks?
>>>>>
>>>>> You do make routine checks don't you?
>>>>>
>>>> Must be "very" low profile if you can't tell the difference when it's
>>>> flat .
>>>
>>>
>>> The shower of sparks from the rims should be a good clue !!
>>> Brad
>> I did manage to drive a Astra est for 5 miles or so round country roads 
>> and I could not make out what was causing a increase in road noise,the car 
>> handled fine that was my first ever puncture and it continued to run on 
>> the rubber rather than the wheel rim, when it was repaired the puncture 
>> was caused by a horse shoe that went right through the tyre much to the 
>> amusement of the kwikfit fitter
>>
>> -- 
> 
> Was the horse hurt? 
> 
> 
not that I noticed :-) he might have had a limp though

-- 
Kevin R
Reply address works

On 11 Sep, 10:45, NOSPAM...@gmail.com wrote:
> On Thu, 11 Sep 2008 10:31:08 퍝, "Brimstone"
>
>
>
>  wrote:
> >Roger Mills wrote:
> >> Does anyone out there have any experience of wireless tyre pressure
> >> monitoring devices - the sort which have special valves containing a
> >> sensor, and a central display with LEDs and a bleeper and report
> >> status?
> >> Yesterday, I wrote off an otherwise perfectly good 225/45x17 tyre
> >> because I had apparently been driving it flat for a while without
> >> noticing.
> >> In days of yore I could always tell by the seat of my pants if a tyre
> >> was a bit flat. But many modern cars are grossly over-tyred, with
> >> very wide low profile tyres which *look* flat when they're not, and
> >> don't really *feel* any different when they are.
>
> >> At £100 a throw, you don't have to write off too many tyres before a
> >> monitoring system would be cheaper.
>
> >> Any comments or recommendations?
>
> >How about manuall checking your tyre pressures weekly, at the same time as
> >you make all your other routine checks?
>
> >You do make routine checks don't you?
>
> Must be "very" low profile if you can't tell the difference when it's
> flat .

The rear Bridgestone tyre on my Honda (also 45 profile) didn't look
flat but had no pressure at all. The sidewalls on some tyres are so
thick it can be hard to tell.

Roger Mills wrote:

> Does anyone out there have any experience of wireless tyre pressure 
> monitoring devices

Have you tried using eyes?  They're wireless and great for detecting low
pressure in tyres, using a system of pattern matching against stored
reference patterns.  You have to use them fairly regularly.  I use mine
before every drive.

Chris

In an earlier contribution to this discussion,
Chris Lawrence   wrote:

> Roger Mills wrote:
>
>> Does anyone out there have any experience of wireless tyre pressure
>> monitoring devices
>
> Have you tried using eyes?  They're wireless and great for detecting
> low pressure in tyres, using a system of pattern matching against
> stored reference patterns.  You have to use them fairly regularly.  I
> use mine before every drive.
>
> Chris

And presumably you also have a system of elaborate mirrors so that you can 
watch the tyres while in motion?

As others have testified, if these very low profile tyres lose pressure, 
they're knackered in very short order!
-- 
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

Roger Mills wrote:

> And presumably you also have a system of elaborate mirrors so that you can 
> watch the tyres while in motion?

S'okay, I was taking the piss.  You just set it up so good!

> As others have testified, if these very low profile tyres lose pressure, 
> they're knackered in very short order!

I can't imagine it does the wheels any favours either :(

Chris

"Chris Lawrence"  wrote in message 
news:48c98cbb$0$521$bed64819@news.gradwell.net...
> Roger Mills wrote:
>
>> And presumably you also have a system of elaborate mirrors so that you 
>> can
>> watch the tyres while in motion?
>
> S'okay, I was taking the piss.  You just set it up so good!
>
>> As others have testified, if these very low profile tyres lose pressure,
>> they're knackered in very short order!
>
> I can't imagine it does the wheels any favours either :(
>
> Chris

I thought some cars use the antilock braking sensors to compare the speed of 
each wheel - over a significant distance. If one is revolving at a different 
speed consistently then it warns of a puncture

John wrote:
> "Chris Lawrence"  wrote in message 
> news:48c98cbb$0$521$bed64819@news.gradwell.net...
>> Roger Mills wrote:
>>
>>> And presumably you also have a system of elaborate mirrors so that you 
>>> can
>>> watch the tyres while in motion?
>> S'okay, I was taking the piss.  You just set it up so good!
>>
>>> As others have testified, if these very low profile tyres lose pressure,
>>> they're knackered in very short order!
>> I can't imagine it does the wheels any favours either :(
>>
>> Chris
> 
> I thought some cars use the antilock braking sensors to compare the speed of 
> each wheel - over a significant distance. If one is revolving at a different 
> speed consistently then it warns of a puncture 
> 
> 
That quite clever. Does it warn of four punctures while you are going 
round a roundabout? Or one, when one wheel is spinning in the verge? :-)

John coughed up some electrons that declared:

> I thought some cars use the antilock braking sensors to compare the speed
> of each wheel - over a significant distance. If one is revolving at a
> different speed consistently then it warns of a puncture

MINIs do that, or at least the latest revision.

Cheers

Tim

In an earlier contribution to this discussion,
John   wrote:

> "Chris Lawrence"  wrote in message
> news:48c98cbb$0$521$bed64819@news.gradwell.net...
>> Roger Mills wrote:
>>
>>> And presumably you also have a system of elaborate mirrors so that
>>> you can
>>> watch the tyres while in motion?
>>
>> S'okay, I was taking the piss.  You just set it up so good!
>>
>>> As others have testified, if these very low profile tyres lose
>>> pressure, they're knackered in very short order!
>>
>> I can't imagine it does the wheels any favours either :(
>>
>> Chris
>
> I thought some cars use the antilock braking sensors to compare the
> speed of each wheel - over a significant distance. If one is
> revolving at a different speed consistently then it warns of a
> puncture

Dunno. Mine doesn't. Besides which, I don't know whether that would work. 
There is a school of thought which says that the distance covered per wheel 
rev is determined by the amount of tread laid on the road - rather than 2 x 
Pi x standing height. If that is that case, a soft tyre would not rotate at 
a higher speed than an inflated one.
-- 
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

"The Natural Philosopher" <a@b.c> wrote in message 
news:1221220481.31632.1@proxy01.news.clara.net...
> John wrote:
>> "Chris Lawrence"  wrote in message 
>> news:48c98cbb$0$521$bed64819@news.gradwell.net...
>>> Roger Mills wrote:
>>>
>>>> And presumably you also have a system of elaborate mirrors so that you 
>>>> can
>>>> watch the tyres while in motion?
>>> S'okay, I was taking the piss.  You just set it up so good!
>>>
>>>> As others have testified, if these very low profile tyres lose 
>>>> pressure,
>>>> they're knackered in very short order!
>>> I can't imagine it does the wheels any favours either :(
>>>
>>> Chris
>>
>> I thought some cars use the antilock braking sensors to compare the speed 
>> of each wheel - over a significant distance. If one is revolving at a 
>> different speed consistently then it warns of a puncture
> That quite clever. Does it warn of four punctures while you are going 
> round a roundabout? Or one, when one wheel is spinning in the verge? :-)

No, that's why he said "over a significant distance" and "consistently". The 
clue is in the words :o)


-- 
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)>

Bob Mannix wrote:
> "The Natural Philosopher" <a@b.c> wrote in message 
> news:1221220481.31632.1@proxy01.news.clara.net...
>> John wrote:
>>> "Chris Lawrence"  wrote in message 
>>> news:48c98cbb$0$521$bed64819@news.gradwell.net...
>>>> Roger Mills wrote:
>>>>
>>>>> And presumably you also have a system of elaborate mirrors so that you 
>>>>> can
>>>>> watch the tyres while in motion?
>>>> S'okay, I was taking the piss.  You just set it up so good!
>>>>
>>>>> As others have testified, if these very low profile tyres lose 
>>>>> pressure,
>>>>> they're knackered in very short order!
>>>> I can't imagine it does the wheels any favours either :(
>>>>
>>>> Chris
>>> I thought some cars use the antilock braking sensors to compare the speed 
>>> of each wheel - over a significant distance. If one is revolving at a 
>>> different speed consistently then it warns of a puncture
>> That quite clever. Does it warn of four punctures while you are going 
>> round a roundabout? Or one, when one wheel is spinning in the verge? :-)
> 
> No, that's why he said "over a significant distance" and "consistently". The 
> clue is in the words :o)
> 
> 
So no use for rallying then ;-)

IIRC F1 cars use some kind of ride height sensing..any assymmetry in the 
hat when going straight, is a puncture..

http://autospeed.com/cms/A_1267/article.html

>>> Chris
>>
>> I thought some cars use the antilock braking sensors to compare the
>> speed of each wheel - over a significant distance. If one is
>> revolving at a different speed consistently then it warns of a
>> puncture
>
> Dunno. Mine doesn't. Besides which, I don't know whether that would work. 
> There is a school of thought which says that the distance covered per 
> wheel rev is determined by the amount of tread laid on the road - rather 
> than 2 x Pi x standing height. If that is that case, a soft tyre would not 
> rotate at a higher speed than an inflated one.
> -- 
> Cheers,
> Roger
> ______

A lengthy article here:

http://www-nrd.nhtsa.dot.gov/pdf/nrd-01/esv/esv19/05-0082-O.pdf

In an earlier contribution to this discussion,
John   wrote:

>>>> Chris
>>>
>>> I thought some cars use the antilock braking sensors to compare the
>>> speed of each wheel - over a significant distance. If one is
>>> revolving at a different speed consistently then it warns of a
>>> puncture
>>
>> Dunno. Mine doesn't. Besides which, I don't know whether that would
>> work. There is a school of thought which says that the distance
>> covered per wheel rev is determined by the amount of tread laid on
>> the road - rather than 2 x Pi x standing height. If that is that
>> case, a soft tyre would not rotate at a higher speed than an
>> inflated one. --
>> Cheers,
>> Roger
>> ______
>
> A lengthy article here:
>
> http://www-nrd.nhtsa.dot.gov/pdf/nrd-01/esv/esv19/05-0082-O.pdf


Thanks - two very useful articles for explaining the technology.

Using the existing ABS speed sensors is clearly cheaper than having 
pressure/temperature sensors in the wheels - but has to be designed into the 
car rather than being suitable for after-market use.

I'd still like to find someone who is using an after-market pressure 
monitoring system in the UK - in order to find out what is available, and 
whether it works ok. Surely there must be *somebody*?!
-- 
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

On Fri, 12 Sep 2008 12:58:02 +0100 Roger Mills wrote :
> There is a school of thought which says that the distance covered per wheel 
> rev is determined by the amount of tread laid on the road - rather than 2 x 
> Pi x standing height. If that is that case, a soft tyre would not rotate at 
> a higher speed than an inflated one.

The article referenced in another post says "The rolling radius of the tire 
becomes smaller in proportion to the rate of deflation and therefore the 
wheel speed of the deflated tire increases."

Surely if the length of the tread is 1.5m (and if it's a steel belt radial or 
similar so won't change with inflation/deflation), travelling this distance 
causes the wheel to rotate once whether fully inflated or running on the rim?

-- 
Tony Bryer SDA UK  'Software to build on'  http://www.sda.co.uk

In an earlier contribution to this discussion,
Tony Bryer   wrote:

> On Fri, 12 Sep 2008 12:58:02 +0100 Roger Mills wrote :
>> There is a school of thought which says that the distance covered
>> per wheel rev is determined by the amount of tread laid on the road
>> - rather than 2 x Pi x standing height. If that is that case, a soft
>> tyre would not rotate at a higher speed than an inflated one.
>
> The article referenced in another post says "The rolling radius of
> the tire becomes smaller in proportion to the rate of deflation and
> therefore the wheel speed of the deflated tire increases."
>
> Surely if the length of the tread is 1.5m (and if it's a steel belt
> radial or similar so won't change with inflation/deflation),
> travelling this distance causes the wheel to rotate once whether
> fully inflated or running on the rim?

That's my feeling too! But them what make pressure monitors based on change 
in radius seem to be claiming otherwise.
-- 
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

Tony Bryer wrote:
> On Fri, 12 Sep 2008 12:58:02 +0100 Roger Mills wrote :
> 
>>There is a school of thought which says that the distance covered per wheel 
>>rev is determined by the amount of tread laid on the road - rather than 2 x 
>>Pi x standing height. If that is that case, a soft tyre would not rotate at 
>>a higher speed than an inflated one.
> 
> 
> The article referenced in another post says "The rolling radius of the tire 
> becomes smaller in proportion to the rate of deflation and therefore the 
> wheel speed of the deflated tire increases."
> 
> Surely if the length of the tread is 1.5m (and if it's a steel belt radial or 
> similar so won't change with inflation/deflation), travelling this distance 
> causes the wheel to rotate once whether fully inflated or running on the rim?

  With lower pressure, the tread gaps will be able to close up a little, 
which will change the 'tread length' more obviously than it will change 
the 'rolling radius'. The article is claiming a 3mm /1% difference, 
which seems plausible, but you would want to cover a long distance 
before deciding the difference in rotation wasn't due to roundabouts.

Tony Bryer wrote:
> On Fri, 12 Sep 2008 12:58:02 +0100 Roger Mills wrote :
>> There is a school of thought which says that the distance covered per wheel 
>> rev is determined by the amount of tread laid on the road - rather than 2 x 
>> Pi x standing height. If that is that case, a soft tyre would not rotate at 
>> a higher speed than an inflated one.
> 
> The article referenced in another post says "The rolling radius of the tire 
> becomes smaller in proportion to the rate of deflation and therefore the 
> wheel speed of the deflated tire increases."
> 
> Surely if the length of the tread is 1.5m (and if it's a steel belt radial or 
> similar so won't change with inflation/deflation), travelling this distance 
> causes the wheel to rotate once whether fully inflated or running on the rim?
> 
Not quite.

The outer layer of tread can be fairly expanded on a fully inflated 
tyre, or rather  compressed on a rather deflated one.

Also you can get slip under traction..

In uk.d-i-y, Nick Finnigan wrote:
>Tony Bryer wrote:
>> On Fri, 12 Sep 2008 12:58:02 +0100 Roger Mills wrote :
>>
>>>There is a school of thought which says that the distance covered per
>>>wheel rev is determined by the amount of tread laid on the road -
>>>rather than 2 x Pi x standing height. If that is that case, a soft
>>>tyre would not rotate at a higher speed than an inflated one.
>>   The article referenced in another post says "The rolling radius of
>>the tire  becomes smaller in proportion to the rate of deflation and
>>therefore the  wheel speed of the deflated tire increases."
>>  Surely if the length of the tread is 1.5m (and if it's a steel belt
>>radial or  similar so won't change with inflation/deflation),
>>travelling this distance  causes the wheel to rotate once whether
>>fully inflated or running on the rim?
>
> With lower pressure, the tread gaps will be able to close up a little,
>which will change the 'tread length' more obviously than it will change
>the 'rolling radius'. The article is claiming a 3mm /1% difference,
>which seems plausible, but you would want to cover a long distance
>before deciding the difference in rotation wasn't due to roundabouts.

Rather than guessing whether you've been driving in a straight line or
not, surely it makes sense to monitor the steering.

-- 
Mike Barnes

Mike Barnes wrote:
> 
> Rather than guessing whether you've been driving in a straight line or
> not, surely it makes sense to monitor the steering.

  Yes, or the lateral acceleration, if there was already a sensor 
monitoring either of them. Otherwise use the existing ABS sensors and 
some less-stupid software in the controller.

On 11 Sep 2008 19:27:43 GMT, Adrian wrote:

> The key is _totally_ flat, rather than just soft.

Agreed no tyre will survive long if internal surafces are being forced 
into contact even just briefly on bumps. That I would call "flat". Soft is 
when there is still pressure in the tyre but it's not enough and the shape 
is visibly different and the handling noticeably altered. This is with 
normal tyres mind not a thick rubber band...

If a tyre picks up a puncture and goes flat when running the chances are 
it will be killed but a slow leak where you loose just a couple of 
psi/week should be picked up by visual observation/change in handling(*) 
or if those don't occur 'cause rubber bands are fitted rather than proper 
tyres you'll have to resort to actual pressure checks.

(*) Trouble is modern cars are very reliable, just feed them fuel and 
drive. Take them to the garage to be serviced occasionally and get the MOT 
if it's old enough to require one. Many drivers simply don't notice via 
the handling or bother to look for a soft tyre. To me a normal profile 
tyre that is 5 to 10psi down is very obvious.

-- 
Cheers
Dave.