"J.D." <jarnodomenico (AT) yahoo (DOT) com> wrote

I've seen those programmes - he usually changes all 4 tyres at once, but
then he drives away really fast without paying. Scandelous! And you quote
him as an example?!?

On Thu, 15 Oct 2009 21:37:26 +0100, Catman
<catman (AT) rustcuore-sportivo (DOT) co.uk> wrote:

I prefer not to need to do that at all though. Why should I endure
even the tiny/major (delete according to driving skill) inconvenience
of it when all I need to say is "new ones on the back, mate" and I can
avoid it completely. That's my point. Lazy does it..

I think the tyre manufacturers (though my opinion should not be
considered fact) are targeting that gray area between driver and
passenger to try and elongate the driver time (for the average driver
of course) before he converts to a passenger even if he can't avoid
that bit!

...Currently shouting "that says faster..faster ha ha hee hee ho ho"
whenever the word "Slow" is painted on the road!!!! 8-| The real
problem is SWMBO who wasn't best pleased when I got a bit of air time
in today over a sequence of decent mounds. Ooops.... I bent a car
(er..my dad's car!!) in the middle doing that... Back doors wouldn't
open afterwards. I was young and stupid then, now I'm no longer
young.. Dammit.

--
Z
Scotland
Alfa Romeo 156 2.4JTD Veloce Leather (sold)
'Oil' be seeing you..
(Email must have the word 'Alfa' in the
subject line to get through auto-filtering)

Zathras wrote:
You may chose to endure it to get the increased traction in wet weather
on the front tyres. Or you may not. Each to their own.

And also,if they said 'deal with the transition because of benefit x'
you just know someone is going to sue them cos their 17 year old idiot
ploughed the Scooby backwards into a bus queue.
Ooops


--
Catman MIB#14 SKoGA#6 TEAR#4 BOTAFOF#38 Apostle#21 COSOC#3
Tyger, Tyger Burning Bright (Remove rust to reply)
116 Giulietta 3.0l Sprint 1.7 GTV TS 156 V6 2.5 S2
Triumph Sprint ST 1050: It's blue, see.
www.cuore-sportivo.co.uk

On Fri, 16 Oct 2009 06:40:44 +0100, Catman
<catman (AT) rustcuore-sportivo (DOT) co.uk> wrote:

Do you get "increased traction" though? As someone staying in one of
the wettest locations in the UK, I have had more than enough
experience of rain! The Met Office even think it's interesting enough
to have a weather station here.

I've found that tyre wear is a bit like swimming..once you're out of
your depth, it doesn't matter how far out of your depth you are. Tyres
either work in the wet or they don't (simplistic, but hey..that's my
findings). Once they don't have enough tread to work in typical road
water, it doesn't matter where you put them on the car they still
don't disperse that water decently. IME this point is about 3mm.

This experience is from my 156 days (things are different now). I used
an uphill corner on the M8 as a tyre test. On a rainy day (plenty to
choose from) if I could start to lose front wheel traction
accelerating at 70mph - the tyres were shot for reliable wet use. This
usually was the 3mm warning.

Below 3mm, I found that tyres lose their wet capabilities quite
rapidly. A new tyre will have about 8mm of tread. For most typical
on-road puddles and water, you don't *need* all 8mm to disperse all
the water. Something better than 3mm will usually do it. This is how I
work it - have enough tread to displace the water all round so wet
grip isn't noticeably affected by tyre positions. Then I can have the
new tyres on the back without worrying about wet traction on the
fronts.

I suspect that some people (not necessarily those present here)
compare useless near-slicks to brand new tyres (where there will be an
extreme difference in both wet and dry capabilities and handling) then
slot those observations in to counter the manufacturers advice.

The above is just my experience of a 156 2.4JTD for over 8 years on
Continental Sport Contact 2 tyres in my wet location. Any variations
may produce other conclusions.

Oddly enough, I was just thinking..what if the above experience is
utter bollocks so I went Googling and (unknown to me until right now)
ROSPA have kindly graphed my experience - so that's two of us with the
same theory now... Ok they imply 4mm before the performance drop off
but my testing isn't as rigorous! They do say to change tyres at 3mm
though.

http://www.rospa.com/roadsafety/advice/motorvehicles/tread_depth.htm

--
Z
Scotland
Alfa Romeo 156 2.4JTD Veloce Leather (sold)
'Oil' be seeing you..
(Email must have the word 'Alfa' in the
subject line to get through auto-filtering)

Zathras wrote:
<snip all good stuff>

But now we're in a circular argument. Since it makes little difference
how much tread you have between 8mm and 3mm (from your observation) even
in the wet, exactly how much does this 'balance of traction' change when
you put new tyres on?

Granted, if you put the full 8mm on the back it *should* be able to
handle deeper / bigger / whatever puddles than the front before it
fails, but in 'normal'[1] conditions, I don't think it's gonna make a
blind bit of difference.

[1] Where you're not constantly running in standing water. This may be
difficult in your location




--
Catman MIB#14 SKoGA#6 TEAR#4 BOTAFOF#38 Apostle#21 COSOC#3
Tyger, Tyger Burning Bright (Remove rust to reply)
116 Giulietta 3.0l Sprint 1.7 GTV TS 156 V6 2.5 S2
Triumph Sprint ST 1050: It's blue, see.
www.cuore-sportivo.co.uk

"Catman" <catman (AT) rustcuore-sportivo (DOT) co.uk> wrote

That's fine mainly if you are driving alone in your yard :-)
On the road are my children, or yours, and there is no reason
for gambling just to show driving skills. That's all about that from me.

J.D. wrote:
Of course there are (children that is), and equally I am not going to
show off any kind of skill.

I am, however, not going to stop applying critical faculties simply
because Michelin et al. wish to simplify things to the level of the
lowest common denominator.




--
Catman MIB#14 SKoGA#6 TEAR#4 BOTAFOF#38 Apostle#21 COSOC#3
Tyger, Tyger Burning Bright (Remove rust to reply)
116 Giulietta 3.0l Sprint 1.7 GTV TS 156 V6 2.5 S2
Triumph Sprint ST 1050: It's blue, see.
www.cuore-sportivo.co.uk

On Fri, 16 Oct 2009 11:47:45 +0100, Catman
<catman (AT) rustcuore-sportivo (DOT) co.uk> wrote:

You mean a multiple argument? There are different issues over dry and
wet handling and whether you've lost grip or not or are just about to,
in varying conditions. People (including me) bounce round all of them
and seeing the wood from the trees can be tricky.

Ah..yes but when things get critical, small differences might become
more significant.

Hmmm..good point. I used "traction balance" because Michelin used it
to describe the different feeling you get after putting new tyres on
the front. Perhaps that's because I used to change my fronts when they
were a bit bald and the difference was extreme. I'm reaching the
limits of my expertise now. You'd probably have to consult a real
expert to get clarity!!

From the ROSPA findings this must be the case. I can only assume the
tyre manufacturers are covering the situation when people have tyres
below 3mm which is quite common in my personal experience! However,
this is my opinion as I am in no position to expand on the tyre
manufacturers advice.

Not the last few weeks but August was total shit. I think the extreme
wetness to be found in these parts helped my Alfa to rust more than I
had expected and hoped for. :-(

--
Z
Scotland
Alfa Romeo 156 2.4JTD Veloce Leather (sold)
'Oil' be seeing you..
(Email must have the word 'Alfa' in the
subject line to get through auto-filtering)

Zathras wrote:
Hence the argument 'it's harder to control a rear wheel skid' is, at
best, simplistic.
They might. I would hazard that at the tipping point of criticality that
the *single* *most* *important* thing is driver skill.
ICBW

Unless car tyres have dual compounds in them (which I have no idea) and
you have worn through the outer, grippy compound, I'm really struggling
to work out why you should feel anything at all. AFAICT you are only
going to lose grip in the wet when you wear out the tread. In the dry,
it should be the same.

Happy to have someone explain why this is wrong, though.

I suspect the perception of change in balance is either due to
1) Psychology i.e. you think you should feel a change, so we do.
2) The sharpness of the tread edges / release compound / not fully
curing of the tyre etc etc. In short, because the tyre is *new*. Brand
new, and this stops happening within n miles.
3) Marketing

It's not like bike tyres which actually change shape and make the bike
harder to tip in as they wear out.

Could well be. Perhaps it should be:

'Since most people think they can feel a difference in traction balance,
have done no training since they passed their test and are probably
using tyres with < 3mm tread on them, we recommend that the new tyres
are put on the rear'



Doesn't have quite the same ring to it.


Downer. I thought the 156s were all galvanized. Was it shunted and repaired?


--
Catman MIB#14 SKoGA#6 TEAR#4 BOTAFOF#38 Apostle#21 COSOC#3
Tyger, Tyger Burning Bright (Remove rust to reply)
116 Giulietta 3.0l Sprint 1.7 GTV TS 156 V6 2.5 S2
Triumph Sprint ST 1050: It's blue, see.
www.cuore-sportivo.co.uk

Catman spoke:
I suspect a mix of 1) and 2)

When I put the cheapos on the 156 I was wary - first opportunity I
deliberately did a wheel spin, and very hard braking. Cornering I was
'cautious' about and the car definitely felt different, but this was with
new tread replacing almost illegal tread.

Within a day or so things calmed down and it now feels sharper handling
than it did with the old rubber on.

--
Rob Pearson
156 1.9jtd sportwagon (now)
164 V6 Lusso (gone)