Tire rot

[Just A User]

Can someone point me in the direction of a photo of the damage that
might occur from storing a bike with its tires on a cold concrete floor.

[Mark]

Just A User wrote:
> Can someone point me in the direction of a photo of the damage that
> might occur from storing a bike with its tires on a cold concrete floor.

Don't think it exists - no such damage. If, though, you add a nearby
deep freeze compressor (or other ozone source), I'm sure there are lots
of examples. Heat is bad for tires as well, at least in the looong term.

Mark J.

[A Muzi]

Just A User wrote:
> Can someone point me in the direction of a photo of the damage that
> might occur from storing a bike with its tires on a cold concrete floor.

No damage if you top them up periodically.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

[becca]

Just A User wrote:
> Can someone point me in the direction of a photo of the damage that
> might occur from storing a bike with its tires on a cold concrete floor.

depends on where you live. i live in colorado, and if you leave tubes or
tires out for long periods (like over a year) without using them, they
dry out and crack. other than that, i don't know that i'd worry about it.

becca

[Tom Keats]

In article <H9qdne-8R-GlyTbbnZ2dnUVZ_quhnZ2d@giganews.com>,
Just A User <ken@up-yours-spammer.net> writes:
> Can someone point me in the direction of a photo of the damage that
> might occur from storing a bike with its tires on a cold concrete floor.

In residential basements, it's not the cold concrete
floor that accelerates tire deterioration, it's the
ozone created by nearby electric motors such as those
in central heating furnaces.

N.B: Rubber doesn't "rot" as in the biological sense
of the word. Rather, it gradually but inexorably
outgasses its more volatile chemical components, causing
the rubber structure to shrink, crack, and eventually
crumble. Ozone and ultraviolet light are reputed to
hasten the process. I think the latter factor (UV light)
is the greater concern.

I /have/ to store my main bike right beside the furnace.
But I wear my tires out just from daily use before the
furnace-motor ozone can kill 'em. But if I just permanently
left my bike out in a sunny spot in the back yard for a
year or two, (perish the thought) the tires would die long
before their time. If the bike wasn't stolen first.

As an aside thought, I also don't believe storing a bike
within a pyramid would prolong the the life of the tires ;-)
Now that I've said that, chances are Carl Fogel will try it.
You can put him up to almost anything that's tastefully and
non-destructively investigative/analytical/experimental <G>
(I say that with the utmost respect.)

cheers,
Tom

--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

[Andrew Price]

On Tue, 11 Mar 2008 01:15:22 -0800, tkeats2005@hotmail.com (Tom Keats)
wrote:

[---]

>Now that I've said that, chances are Carl Fogel will try it.
>You can put him up to almost anything that's tastefully and
>non-destructively investigative/analytical/experimental <G>

Agreed !

>(I say that with the utmost respect.)

So do I - I rather keep hoping he'll do an in-depth investigation into
the benefits and disadvantages of cotton vs synthetics in clothing!

[dlzc]

Dear Tom Keats:

On Mar 11, 2:15*am, tkeats2...@hotmail.com (Tom Keats) wrote:
...
> N.B: *Rubber doesn't "rot" as in the biological sense
> of the word. *Rather, it gradually but inexorably
> outgasses its more volatile chemical components,
> causing the rubber structure to shrink, crack, and
> eventually crumble. *Ozone and ultraviolet light are
> reputed to hasten the process. *I think the latter
> factor (UV light) is the greater concern.

There are chambers that age rubber at an accelerated rate. They do
not bathe the rubber sample in UV, but they do bathe them in ozone.
If you irradiate rubber with UV, in an atmosphere without oxygen, you
do not get anything close to the degradation you describe above.

Just keep in mind that visible light (purple to UV), NOx (from
automobile emissions), and VOCs (even methane) make ozone. So it is
"natural" to attribute the damage to "the light". It just is not
strictly correct.

David A. Smith

[carlfogel@comcast.net]

On Tue, 11 Mar 2008 01:15:22 -0800, tkeats2005@hotmail.com (Tom Keats)
wrote:

[snip]

>I /have/ to store my main bike right beside the furnace.
>But I wear my tires out just from daily use before the
>furnace-motor ozone can kill 'em. But if I just permanently
>left my bike out in a sunny spot in the back yard for a
>year or two, (perish the thought) the tires would die long
>before their time. If the bike wasn't stolen first.
>
>As an aside thought, I also don't believe storing a bike
>within a pyramid would prolong the the life of the tires ;-)
>Now that I've said that, chances are Carl Fogel will try it.

Dear Tom,

Well . . .

These highwheeler tires from around 1890 are past their prime:


http://www.hochrad.info/hochradseite/hochradteile/hochrad%20teile%20reifen.htm

But tire manufacturers have improved things considerably since the
1870s when rubber tires first appeared.

You'd have to store modern tires under a pyramid for years before they
reached their expected lifespan in sunlight.

The tires of cars parked on streets survive years of sunlight.

So do the tires of bicycles left outside--think of kids' bikes and
commuter bicycles.

Sunlight and ozone do indeed damage rubber, but not usually at the
rates suggested by our fevered imaginations, which lead people to
store tires in plastic bags in freezers.

Cheers,

Carl Fogel

[John Henderson]

Tom Keats wrote:

> In article <H9qdne-8R-GlyTbbnZ2dnUVZ_quhnZ2d@giganews.com>,
> Just A User <ken@up-yours-spammer.net> writes:
>> Can someone point me in the direction of a photo of the
>> damage that might occur from storing a bike with its tires on
>> a cold concrete floor.
>
> In residential basements, it's not the cold concrete
> floor that accelerates tire deterioration, it's the
> ozone created by nearby electric motors such as those
> in central heating furnaces.
>
> N.B: Rubber doesn't "rot" as in the biological sense
> of the word. Rather, it gradually but inexorably
> outgasses its more volatile chemical components, causing
> the rubber structure to shrink, crack, and eventually
> crumble. Ozone and ultraviolet light are reputed to
> hasten the process. I think the latter factor (UV light)
> is the greater concern.
>
> I /have/ to store my main bike right beside the furnace.
> But I wear my tires out just from daily use before the
> furnace-motor ozone can kill 'em. But if I just permanently
> left my bike out in a sunny spot in the back yard for a
> year or two, (perish the thought) the tires would die long
> before their time. If the bike wasn't stolen first.
>
> As an aside thought, I also don't believe storing a bike
> within a pyramid would prolong the the life of the tires ;-)
> Now that I've said that, chances are Carl Fogel will try it.
> You can put him up to almost anything that's tastefully and
> non-destructively investigative/analytical/experimental <G>
> (I say that with the utmost respect.)

I see that Michelin claims to have addressed this issue:

"PROTEK, a brand-new technology that is particularly effective
against damage caused by UV rays, ozone, temperature variations
and pinched tubes"

http://tinyurl.com/2fnd6s

John

[datakoll]

Hang the bike, lift tires off the floor. Opinion here is Galiliean:
bikes tires flatten if left in one position. Auto tires do it, people
do it, rocks do it, wine and beer do it, glass does it-glass is a
fluid.
Bike tires are unsecured in the carcass compared to auto tires.
Concrete is very basic, maybe this isnot good for rubber.

[Ryan Cousineau]

In article <5fnct39dphs4elqe9mt2qchnmbvflobk4g@4ax.com>,
Andrew Price <ajprice@free.fr> wrote:

> On Tue, 11 Mar 2008 01:15:22 -0800, tkeats2005@hotmail.com (Tom Keats)
> wrote:
>
> [---]
>
> >Now that I've said that, chances are Carl Fogel will try it.
> >You can put him up to almost anything that's tastefully and
> >non-destructively investigative/analytical/experimental <G>
>
> Agreed !
>
> >(I say that with the utmost respect.)
>
> So do I - I rather keep hoping he'll do an in-depth investigation into
> the benefits and disadvantages of cotton vs synthetics in clothing!

Hm. What kind of information are you looking for? The pros and cons of
cotton and synthetics (and wool) are pretty well understood at this
point. A really spiffy double-blind test might add a few extra decimal
places of precision, but the broad generalization that cotton gets wet
and stays wet, while synthetics and wool tend to wick water away from
the skin are both easily verified and the reason the latter two
materials predominate in sportswear.

Cotton is inexpensive, light, and feels nice against the skin. It's not
much fun when wet, and isn't as warm, weight for weight, as either
synthetics or wool. On the other hand, it isn't as warm (or itchy!) as
wool, so that's why it's popular for casual wear in climat-controlled
environments, or as base layers for people not planning to break a sweat.

I am now waiting for someone to start advocating for linen cycling
apparel,

--
Ryan Cousineau rcousine@gmail.com http://www.wiredcola.com/
"In other newsgroups, they killfile trolls."
"In rec.bicycles.racing, we coach them."

[carlfogel@comcast.net]

On Tue, 11 Mar 2008 06:17:22 -0700 (PDT), datakoll
<datakoll@yahoo.com> wrote:

>bikes tires flatten if left in one position. Auto tires do it, people
>do it, rocks do it, wine and beer do it, glass does it-glass is a
>fluid.

Dear Gene,

Actually, it's a well-refuted myth that glass windows flow and sag
under gravity:


http://groups.google.com/group/rec.bicycles.racing/msg/850d41637743b6c1

Some old glass windows do indeed look as if they have sagged, but they
looked that way the day they were set in the frame.

Cheers,

Carl Fogel

[datakoll]

doowwwwwwwwwwwwnwind
http://www.nws.noaa.gov/aq/sectors/conus.php

say whattabout RADON?

[dlzc]

On Mar 11, 9:01*am, datakoll <datak...@yahoo.com> wrote:
> doowwwwwwwwwwwwnwind
http://www.nws.noaa.gov/aq/sectors/conus.php
>
> say whattabout RADON?

It is a noble gas, so is unlikely to chemically affect tubber. Its
decay products are a different story. Still, without oxygen...

David A. Smith

[Michael Press]

In article <aghdt3les7rt2g13kgd6ibcimvib1mep6l@4ax.com>,
carlfogel@comcast.net wrote:

> The tires of cars parked on streets survive years of sunlight.

The rubber is made with a sacrificial compound.
The sacrificial compound reacts more rapidly with
ozone and forms a powder layer on the tire.
If you want to protect the tire, leave it on there
and do not attack your tires with costly
products that only make it look shiny and
leaves black goo on any part of your person
that touches it.

--
Michael Press

[raamman@gmail.com]

On Mar 11, 1:31*pm, carlfo...@comcast.net wrote:
> On Tue, 11 Mar 2008 06:17:22 -0700 (PDT), datakoll
>
> <datak...@yahoo.com> wrote:
> >bikes tires flatten if left in one position. Auto tires do it, people
> >do it, rocks do it, wine and beer do it, glass does it-glass is a
> >fluid.
>
> Dear Gene,
>
> Actually, it's a well-refuted myth that glass windows flow and sag
> under gravity:
>
> http://groups.google.com/group/rec.bicycles.racing/msg/850d41637743b6c1
>
> Some old glass windows do indeed look as if they have sagged, but they
> looked that way the day they were set in the frame.
>
> Cheers,
>
> Carl Fogel

I remember my old grade 8 teacher telling us that glass is a very very
slow liquid- but then I discovered he was an idiot as almost all the
incredulous nonsense he taught was just that. well mr sharp; turned
out you weren't so sharp at all...sincerely, former student

[datakoll]

On Mar 11, 2:31*pm, carlfo...@comcast.net wrote:
> On Tue, 11 Mar 2008 06:17:22 -0700 (PDT), datakoll
>
> <datak...@yahoo.com> wrote:
> >bikes tires flatten if left in one position. Auto tires do it, people
> >do it, rocks do it, wine and beer do it, glass does it-glass is a
> >fluid.
>
> Dear Gene,
>
> Actually, it's a well-refuted myth that glass windows flow and sag
> under gravity:
>
> http://groups.google.com/group/rec.bicycles.racing/msg/850d41637743b6c1
>
> Some old glass windows do indeed look as if they have sagged, but they
> looked that way the day they were set in the frame.
>
> Cheers,
>
> Carl Fogel

Veeeaaaaaaalllllll Carl, why is the window's wide end on the bottom?
because the wide end religiously supports the narrow top or did the
masons, as experienced a crew as you'd not wanna meet, misunderstand
the flow of water?

anyway, Herpo, cycle rubber isnot autpo rubber and I have seen first
hand sunlight not Ozone degraded Conti TT. That rubber looked like uh
sundegraded rubber. You live in the desert....

[datakoll]

UNNNGH,

WHEN THE Cathedral at Chartes was restored, rumor was or is,
measurments made on stained glass set in uhuhuh 1237? showed glass was
wider at bottom than at top, that measurments conformed to equations
for glass flow.
Glass is typed as a solid liquid thru crystalized molecular structure.

That is now incorrect? My day is ruined.

Older tires set out in Florida's sun degrade without significant ozone
not so much newer compounds.

G. Daniels

[Michael Press]

In article
<ddb08af1-6ab9-47f1-969a-d2c9300aeb39@e23g2000prf.googlegroups.com>,
raamman@gmail.com wrote:

> On Mar 11, 1:31*pm, carlfo...@comcast.net wrote:
> > On Tue, 11 Mar 2008 06:17:22 -0700 (PDT), datakoll
> >
> > <datak...@yahoo.com> wrote:
> > >bikes tires flatten if left in one position. Auto tires do it, people
> > >do it, rocks do it, wine and beer do it, glass does it-glass is a
> > >fluid.
> >
> > Actually, it's a well-refuted myth that glass windows flow and sag
> > under gravity:
> >
> > http://groups.google.com/group/rec.bicycles.racing/msg/850d41637743b6c1
> >
> > Some old glass windows do indeed look as if they have sagged, but they
> > looked that way the day they were set in the frame.
>
> I remember my old grade 8 teacher telling us that glass is a very very
> slow liquid- but then I discovered he was an idiot as almost all the
> incredulous nonsense he taught was just that. well mr sharp; turned
> out you weren't so sharp at all...sincerely, former student

Flow rate is proportional to, among other things, the curvature
of the surface. If glass flowed, the sharp corner of a glass
shard should dull rapidly. Such is not the case. Glass knives
hundreds of years old have their edge.

--
Michael Press

[Michael Press]

In article <63o3rdF28216aU2@mid.individual.net>,
John Henderson <jhenRemoveThis@talk21.com> wrote:

> Tom Keats wrote:
>
> > In article <H9qdne-8R-GlyTbbnZ2dnUVZ_quhnZ2d@giganews.com>,
> > Just A User <ken@up-yours-spammer.net> writes:
> >> Can someone point me in the direction of a photo of the
> >> damage that might occur from storing a bike with its tires on
> >> a cold concrete floor.
> >
> > In residential basements, it's not the cold concrete
> > floor that accelerates tire deterioration, it's the
> > ozone created by nearby electric motors such as those
> > in central heating furnaces.
> >
> > N.B: Rubber doesn't "rot" as in the biological sense
> > of the word. Rather, it gradually but inexorably
> > outgasses its more volatile chemical components, causing
> > the rubber structure to shrink, crack, and eventually
> > crumble. Ozone and ultraviolet light are reputed to
> > hasten the process. I think the latter factor (UV light)
> > is the greater concern.
> >
> > I /have/ to store my main bike right beside the furnace.
> > But I wear my tires out just from daily use before the
> > furnace-motor ozone can kill 'em. But if I just permanently
> > left my bike out in a sunny spot in the back yard for a
> > year or two, (perish the thought) the tires would die long
> > before their time. If the bike wasn't stolen first.
> >
> > As an aside thought, I also don't believe storing a bike
> > within a pyramid would prolong the the life of the tires ;-)
> > Now that I've said that, chances are Carl Fogel will try it.
> > You can put him up to almost anything that's tastefully and
> > non-destructively investigative/analytical/experimental <G>
> > (I say that with the utmost respect.)
>
> I see that Michelin claims to have addressed this issue:
>
> "PROTEK, a brand-new technology that is particularly effective
> against damage caused by UV rays, ozone, temperature variations
> and pinched tubes"

Automobile tires have been made with sacrificial compounds
for years. Michelin wants you to think that only they
do it.

--
Michael Press

[Ryan Cousineau]

In article
<e0e3d07c-c684-403d-a2e4-c4387d4974f6@i7g2000prf.googlegroups.com>,
datakoll <datakoll@yahoo.com> wrote:

> On Mar 11, 2:31*pm, carlfo...@comcast.net wrote:
> > On Tue, 11 Mar 2008 06:17:22 -0700 (PDT), datakoll
> >
> > <datak...@yahoo.com> wrote:
> > >bikes tires flatten if left in one position. Auto tires do it, people
> > >do it, rocks do it, wine and beer do it, glass does it-glass is a
> > >fluid.
> >
> > Dear Gene,
> >
> > Actually, it's a well-refuted myth that glass windows flow and sag
> > under gravity:
> >
> > http://groups.google.com/group/rec.bicycles.racing/msg/850d41637743b6c1
> >
> > Some old glass windows do indeed look as if they have sagged, but they
> > looked that way the day they were set in the frame.
> >
> > Cheers,
> >
> > Carl Fogel
>
> Veeeaaaaaaalllllll Carl, why is the window's wide end on the bottom?
> because the wide end religiously supports the narrow top or did the
> masons, as experienced a crew as you'd not wanna meet, misunderstand
> the flow of water?

Same reason the tire's label always goes beside the tire valve:
tradition combined with some kernel of practicality.

--
Ryan Cousineau rcousine@gmail.com http://www.wiredcola.com/
"In other newsgroups, they killfile trolls."
"In rec.bicycles.racing, we coach them."

[carlfogel@comcast.net]

On Tue, 11 Mar 2008 23:30:14 GMT, Ryan Cousineau <rcousine@gmail.com>
wrote:

>In article
><e0e3d07c-c684-403d-a2e4-c4387d4974f6@i7g2000prf.googlegroups.com>,
> datakoll <datakoll@yahoo.com> wrote:
>
>> On Mar 11, 2:31*pm, carlfo...@comcast.net wrote:
>> > On Tue, 11 Mar 2008 06:17:22 -0700 (PDT), datakoll
>> >
>> > <datak...@yahoo.com> wrote:
>> > >bikes tires flatten if left in one position. Auto tires do it, people
>> > >do it, rocks do it, wine and beer do it, glass does it-glass is a
>> > >fluid.
>> >
>> > Dear Gene,
>> >
>> > Actually, it's a well-refuted myth that glass windows flow and sag
>> > under gravity:
>> >
>> > http://groups.google.com/group/rec.bicycles.racing/msg/850d41637743b6c1
>> >
>> > Some old glass windows do indeed look as if they have sagged, but they
>> > looked that way the day they were set in the frame.
>> >
>> > Cheers,
>> >
>> > Carl Fogel
>>
>> Veeeaaaaaaalllllll Carl, why is the window's wide end on the bottom?
>> because the wide end religiously supports the narrow top or did the
>> masons, as experienced a crew as you'd not wanna meet, misunderstand
>> the flow of water?
>
>Same reason the tire's label always goes beside the tire valve:
>tradition combined with some kernel of practicality.

Dear Ryan,

And like labels on tires, it turns out that some ancient windows had
the thicker end at the side or at the top, and the waviness sometimes
goes sideways.

A few links . . .

A quick summary of the legend at wikipedia:
http://en.wikipedia.org/wiki/Glass#Behavior_of_antique_glass

Nope, says Dow-Corning, a company that knows a bit about glass:
http://www.cmog.org/index.asp?pageId=745

A 1200-line hodge-podge of discussion that ends up pointing out that
the slightest flowing of glass would be grossly obvious in old
telescope lenses, but is never seen:
http://tafkac.org/science/glass.flow/glass_flow_the_thread.html

More fun at an urban legend site:

http://dwb.unl.edu/Teacher/NSF/C01/C01Links/www.ualberta.ca/~bderksen/florin.html#antique

Cheers,

Carl Fogel

[Leo Lichtman]

"datakoll" wrote: (clip)Glass is typed as a solid liquid thru crystalized
molecular structure. (clip)
^^^^^^^^^^^^^^^^^^^
Does that mean they can be recycled into liquid crystal displays in
calculators? ;-)

[Michael Press]

In article
<01e79eb2-736a-4c24-b444-12f38ed9c7f2@x41g2000hsb.googlegroups.com>,
datakoll <datakoll@yahoo.com> wrote:

> UNNNGH,
>
> WHEN THE Cathedral at Chartes was restored, rumor was or is,
> measurments made on stained glass set in uhuhuh 1237? showed glass was
> wider at bottom than at top, that measurments conformed to equations
> for glass flow.
> Glass is typed as a solid liquid thru crystalized molecular structure.
>
> That is now incorrect? My day is ruined.
>
> Older tires set out in Florida's sun degrade without significant ozone
> not so much newer compounds.

Look up glass transition temperature.
We all had this discussion not too long ago.

--
Michael Press

[still just me]

On Tue, 11 Mar 2008 16:47:46 -0700 (PDT), datakoll
<datakoll@yahoo.com> wrote:

>
>WHEN THE Cathedral at Chartes was restored, rumor was or is,
>measurments made on stained glass set in uhuhuh 1237? showed glass was
>wider at bottom than at top, that measurments conformed to equations
>for glass flow.
>Glass is typed as a solid liquid thru crystalized molecular structure.
>
>That is now incorrect? My day is ruined.

Wait... when I stop laughing I will type....

OK now. I've seen plenty of windows hundreds of years old in local
houses. If they continued to flow, there'd be no glass left at the top
or at least there would be a visible difference in the glass
thickness. There isn't, at least not on a consistent basis. I would
assume that a craftsman building a window would put the thicker side
down as a matter of better building practice, but they don't change
over time.

[John Henderson]

Michael Press wrote:

> Automobile tires have been made with sacrificial compounds
> for years. Michelin wants you to think that only they
> do it.

Perhaps the correct conclusion is that they've just started, as
far as bikes are concerned.

John

[Michael Press]

In article <63p4p8F27njs5U1@mid.individual.net>,
John Henderson <jhenRemoveThis@talk21.com> wrote:

> Michael Press wrote:
>
> > Automobile tires have been made with sacrificial compounds
> > for years. Michelin wants you to think that only they
> > do it.
>
> Perhaps the correct conclusion is that they've just started, as
> far as bikes are concerned.

Do you suppose that bicycle tire manufactures went to
the trouble of making bicycle tire compound different
from the compound the use to make automobile tires?

--
Michael Press

[John Henderson]

Michael Press wrote:

> In article <63p4p8F27njs5U1@mid.individual.net>,
> John Henderson <jhenRemoveThis@talk21.com> wrote:
>
>> Michael Press wrote:
>>
>> > Automobile tires have been made with sacrificial compounds
>> > for years. Michelin wants you to think that only they
>> > do it.
>>
>> Perhaps the correct conclusion is that they've just started,
>> as far as bikes are concerned.
>
> Do you suppose that bicycle tire manufactures went to
> the trouble of making bicycle tire compound different
> from the compound the use to make automobile tires?

If they come from a different sub-contracting factory, then the
"trouble" might be the other way around.

John

[still just me]

On Thu, 13 Mar 2008 06:05:43 +1100, John Henderson
<jhenRemoveThis@talk21.com> wrote:

>> Do you suppose that bicycle tire manufactures went to
>> the trouble of making bicycle tire compound different
>> from the compound the use to make automobile tires?
>
>If they come from a different sub-contracting factory, then the
>"trouble" might be the other way around.

I don't think it's "trouble" so much as "blend". Down at the rubber
product (pick one) factory, they blend up different rubber mixes for
each product they produce. It's not so much "trouble" as it is
standard fare in the industry. I'm quite certain that bicycle tires
are made with different compounds than auto tires (in fact, the rubber
blend from one auto tire model to the next varies substantially).

[carlfogel@comcast.net]

On Thu, 13 Mar 2008 03:08:16 GMT, still just me
<wheeledBobNOSPAM@yahoo.com> wrote:

>On Thu, 13 Mar 2008 06:05:43 +1100, John Henderson
><jhenRemoveThis@talk21.com> wrote:
>
>>> Do you suppose that bicycle tire manufactures went to
>>> the trouble of making bicycle tire compound different
>>> from the compound the use to make automobile tires?
>>
>>If they come from a different sub-contracting factory, then the
>>"trouble" might be the other way around.
>
>I don't think it's "trouble" so much as "blend". Down at the rubber
>product (pick one) factory, they blend up different rubber mixes for
>each product they produce. It's not so much "trouble" as it is
>standard fare in the industry. I'm quite certain that bicycle tires
>are made with different compounds than auto tires (in fact, the rubber
>blend from one auto tire model to the next varies substantially).

Dear John and Bob,

From the online BikePro catalogue section on bicycle tires, roughly
the same as in my 1994 copy:

"As a protective agent against UV damage tire makers use additives
that inhibit, but don't prevent UV damage, which act as light
absorbers such as Tinuvin P and the 2-hydroxybenzophenones. At time of
vulcanization the zinc salt of mercaptobenzimidazole (ZMBI) is
introduced as an ingredient to increase the resistance to heat
degradation. In the same process, to inhibit the effect of sunlight,
2% of nickel dibutyldithiocarbamate may be used. Atmospheric oxygen
attacks rubber slowly, which causes it to become hard and brittle, so
relatively insoluble waxes are incorporated into the tire compound
which migrates or blooms to the rubber surface, protecting it until
the wax surface is broken. The incorporated wax produces a whitish
tinge on a new tire when it is rolled tightly between the fingers or
possibly pinched."

http://www.bikepro.com/products/tires/tireover.html

Cheers,

Carl Fogel

[John Henderson]

carlfogel@comcast.net wrote:

> Dear John and Bob,
>
> From the online BikePro catalogue section on bicycle tires,
> roughly the same as in my 1994 copy:
>
> "As a protective agent against UV damage tire makers use
> additives that inhibit, but don't prevent UV damage, which act
> as light absorbers such as Tinuvin P and the
> 2-hydroxybenzophenones. At time of vulcanization the zinc salt
> of mercaptobenzimidazole (ZMBI) is introduced as an ingredient
> to increase the resistance to heat degradation. In the same
> process, to inhibit the effect of sunlight, 2% of nickel
> dibutyldithiocarbamate may be used. Atmospheric oxygen attacks
> rubber slowly, which causes it to become hard and brittle, so
> relatively insoluble waxes are incorporated into the tire
> compound which migrates or blooms to the rubber surface,
> protecting it until the wax surface is broken. The
> incorporated wax produces a whitish tinge on a new tire when
> it is rolled tightly between the fingers or possibly pinched."
>
> http://www.bikepro.com/products/tires/tireover.html

Thanks Carl. I'd expect that this "anti-aging" technology is
improving as time goes on. Michelin is a reputable company,
and I'd expect at least a significant reformulation if they're
going to make a public announcement about it.

I took delivery of a new "Michelin City" tyre only a couple of
days ago, and that's what prompted me to search for "Protek
plus", as mentioned on the label and on tyre itself.

What impresses me most about this tyre is the inflation
pressure. It's 26 x 1.85 (and big for that size - a little
wider than a 26 x 2.00 Schwalbe). The maximum inflation
pressure is 87 PSI.

John