Tire rot

In article <[email hidden]>,

John Henderson said:

Michael Press said:

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

Michael Press said:

In article <[email hidden]>,

John Henderson said:

Michael Press said:

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

John Henderson said:

Quoted message said:

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).

Quoted message said:

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

still just me said:

John Henderson said:

Quoted message said:

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

datakoll said:

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.