Difference between 'wear' and 'degradation'?

[~misfit~]

During the red-flagged portion of the Monaco GP there was an interview with
Paul Hembery in which, after the interviewer mentioned all the teams could
now change tyres. He then asked "What sort of wear are we seeing?", to which
Hembery replied:

"The wear's actually been the limiting factor. Normally this season it's
been degradation but they're all in negative degradation up until the
changes (new tyres under red), it's been wear-limited today."

Anyone care to explain that? Also what is "negative degradation"?
--
/Shaun.

"Humans will have advanced a long, long, way when religious belief has a
cozy little classification in the DSM."
David Melville (in r.a.s.f1)

[AC]

~misfit~ wrote:
> During the red-flagged portion of the Monaco GP there was an interview with
> Paul Hembery in which, after the interviewer mentioned all the teams could
> now change tyres. He then asked "What sort of wear are we seeing?", to which
> Hembery replied:
>
> "The wear's actually been the limiting factor. Normally this season it's
> been degradation but they're all in negative degradation up until the
> changes (new tyres under red), it's been wear-limited today."
>
> Anyone care to explain that? Also what is "negative degradation"?
>

Until some one comes up with actual facts, I'll have a go.....

Wear is where the rubber of the tire leaves the tyre. Grip remains
constant. Like sanding wood. Expected wear rates with in designed
operating ranges.

Degradation is some sort of compound change due to heat. Grip changes.
Tyres melting. Chunks falling off. Out of operating ranges.

Any good?

--
AC

[News]

IOW, "Pirellis"

[Bigbird]

Yup. IOW...
Wear is reduction in thickness of the rubber ("tread").
Degradation is reduction in performance.

Now if Bobster understood the difference he might understand why
Pirelli aren't doing "exactly what they were asked to do". :)

[~misfit~]

Yeah... But Hembery said they were all in "negative degradation"? WTF is
that?

>> Any good?
>
> IOW, "Pirellis"

Designed to FIA specs. Pirelli are between a rock and another rock.

I'd like to get away from the mud-slinging for a bit and try to get my head
around what's actually going on with the tyres and the biggest clue I've
seen is that statement from Hembery - but I don't know how to dechiper it
beyond speculation. Also the specuation I've come up with doesn't feel
'right' w/r/t materials science. <shrug>

I mean, it's obvious from the above that wear and deg are two completely
unrelated things. I find that hard to get my head around - previously I
thought that they were at least related. However for tyres to be 60% worn
but be in neg deg WTF does that mean? Is 'degradation' something above and
beyond normal wear? (Requires a rigid definition of 'normal'.) But then how
can you have a negative value?

My only hope (borne out by the lack of a tyre contract for next year[?]) is
that, with the introduction of the new engine / aero rules the FIA will do
away with frangible tyres for 2014 and beyond. <fingers crossed>

[AC]

Well, to be fair, I hadn't really thought about it in that much detail
until the question came up. In being "forced" to think about it in more
depth, Im open to doing a 180 degree turn on my opinion. I would have
said until now Pirelli were doing as asked.

But I think there is a middle ground here. Im struggling to understand
it, let alone explain it. The falling apart bit is the problem, but
people seem hung up on the number of of pit stops and drivers managing
tyres. But even if the de-lamination bit is solved, I assume there would
still be lots of stops and management in a stint. So, there could be a
point where Pirelli say, we have solved it, but many fans wont see or
understand that.

Then we get the team politics and self interest thrown in which over
shadows the technical explanations in the various media, which,
incidental, seem to have been quite poor.

Anyway, too tired to look it up, but some thing in the construction
changed to or from kevlar to or from steel, right? Im there for assuming
that the rubber that contracts the track is probably pretty much as last
year, but this carcass construction change is what has gone wrong,
causing the degradation and de-lamination. So, presumably the rubber is
exactly what was asked for, but its been ruined by the change in carcass
construction. Which, is the bit the drivers and teams object to having
to drive round.

Like I say, Im struggling with this, so......

--
AC

[Sir Tim]

"Bigbird" <Bigbird.us...@Gmail.com> wrote:

> AC wrote:
>> Degradation is some sort of compound change due to heat. Grip
>> changes. Tyres melting. Chunks falling off. Out of operating ranges.
>>
>> Any good?
>
> Yup. IOW...
> Wear is reduction in thickness of the rubber ("tread").
> Degradation is reduction in performance.
>
> Now if Bobster understood the difference he might understand why
> Pirelli aren't doing "exactly what they were asked to do". :)

Actually Bob's in the clear - it was *me* who said that. Perhaps I should
have said "more or less what they were asked to do".

--
Henry Birkin, Bt.

[Bobster]

On May 31, 11:24 am, Sir Tim <bent...@brooklands.co.uk> wrote:

> Actually Bob's in the clear - it was *me* who said that. Perhaps I should
> have said "more or less what they were asked to do".

Very sporting of you.

[Bobster]

On May 30, 10:56 am, AC <x...@xxx.xxx> wrote:

> Wear is where the rubber of the tire leaves the tyre. Grip remains
> constant. Like sanding wood. Expected wear rates with in designed
> operating ranges.
>
> Degradation is some sort of compound change due to heat. Grip changes.
> Tyres melting. Chunks falling off. Out of operating ranges.

I'd say that wear is degradation but that degradation need not be
wear.

If I take a piece of cheese out of the fridge and grate it then that's
wear.

If I simply leave the piece of cheese lying on the window sill then it
will degrade but it won't wear.

Of course it's possible that Hembery is just rattling off something
that sounds impressive and a little mysterious to shut up some nosy
media type person.

[AC]

I'm not replying seriously to anything with cheese as an example.

Cheese is evil in every way.

--
AC

[WrongWayWade]

Wrong. Cheese is food of the gods. Protein, fat, salt. What more can you
ask for?

[News]

Bacon

[AC]

Something not rotten and not alive.

--
AC

[Mark Jackson]

http://www.cheesehouse.com/baconcheese.aspx

--
Mark Jackson - http://www.alumni.caltech.edu/~mjackson
Man will become better when you show him what he is like.
- Anton Chekhov

[News]

Mmmmmmmm.......

[Bobster]

On May 31, 3:48 pm, AC <x...@xxx.xxx> wrote:

> I'm not replying seriously to anything with cheese as an example.
>
> Cheese is evil in every way.

Lol.

[Bigbird]

Sir Tim wrote:

> "Bigbird" <Bigbird.us...@Gmail.com> wrote:
> > AC wrote:
> >> Degradation is some sort of compound change due to heat. Grip
> >> changes. Tyres melting. Chunks falling off. Out of operating
> ranges. >>
> >> Any good?
> >
> > Yup. IOW...
> > Wear is reduction in thickness of the rubber ("tread").
> > Degradation is reduction in performance.
> >
> > Now if Bobster understood the difference he might understand why
> > Pirelli aren't doing "exactly what they were asked to do". :)
>

> Actually Bob's in the clear - it was me who said that. Perhaps I

> should have said "more or less what they were asked to do".

It's the bits they do "less" well which are contreversial. I am
uncomfortable with the acceptance that a tyre with limited wear should
degrade in an unpredictable and difficult to manage manner.

In this respect I believe what they were asked for was limited wear;
hhat they have provided is difficult to manage degradation and
unpredictable performance.

[News]

Asked for a nice block of bacon cheddar, got a dated tub of cottage
cheese...

[Mike Fleming]

In article <koas9o$pmm$2...@dont-email.me>, News <Ne...@Group.Post>
writes:

Bacon, brie and redcurrant baguette. Shame my better half only lets me
have that once per blue moon.

--
Mike Fleming

[AC]

Is she a priest?

--
AC

[Brian Lawrence]

On 30/05/2013 09:56, AC wrote:

>> "The wear's actually been the limiting factor. Normally this season it's
>> been degradation but they're all in negative degradation up until the
>> changes (new tyres under red), it's been wear-limited today."
>>
>> Anyone care to explain that? Also what is "negative degradation"?

Haven't looked at this fred for a while. Surely if degradation is
equivalent to loss of performance, IE slower lap times, then neg. deg.
must be better performance, faster lap times. N'est-ce pas?

--

Brian W Lawrence
Wantage
Oxfordshire

[Mike Fleming]

In article <b0uler...@mid.individual.net>, Brian Lawrence

IIRC, tyres a few years ago used to go through a graining phase when
their performance fell off, then they'd go through that and
performance would recover. Could this be the same phenomenon?

--
Mike Fleming

[News]

More likely a failure to fall off at the expected rate, IOW, "making
duration"