Avocet Touring Tires

Of course, my previous comments only apply to hard surfaces, like
pavement of rock. In dirt, thread does have a purpose, it helps grab the
loose surface.

Legal disclaimer: Done

- -

"May you have the wind at your back.
And a really low gear for the hills!"

Chris Zacho ~ "Your Friendly Neighborhood Wheelman"

Chris'Z Corner
http://www.geocities.com/czcorner

Richard Amirault wrote:

"Don DeMair" wrote ...

I'm looking for a good touring tire. One that will be puncture resistant,
especially in the rain. I've tried the Specialized Armadillo and was

pretty

happy with it, I may buy it again. The other tire I tried was the
Continental Top Touring. I found this tire to ride a bit harsh.

I would prefer a slick tire (without a tread pattern) because I think the
inverted tread actually catches debris and may lead to more flats. I also
don't believe that tread pattern does anything to improve wet or dry grip
on the road. And I don't use my touring bike off-road.

While a slick tire would certain improve traction on dry roads ... I don't
see why you think a tread won't improve wet road traction ... unless your
tire "contact point" is so small and your speed is so slow that you would
not hydroplane in puddles.

The rule developed for estimating when hydroplaning conditions exist for
landing planes which have smooth tires is that
V(mph) = 10 * tire pressure (psi).

Since I generally run my tires at about 100 psi and keep my speed below
100 mph I satisfy your condition that the "contact point is so small and
your speed is so slow that you would not hydroplane."

In the automotive (and motorcycle) world the
main (if not the only) reason for tread in a street tire is for wet weather
use.

With tire pressures around 30 psi and speeds over 55 mph hydroplaning
becomes a serious problem.

Peter wrote:

Richard Amirault wrote:

"Don DeMair" wrote ...

I'm looking for a good touring tire. One that will be puncture
resistant,
especially in the rain. I've tried the Specialized Armadillo and was


pretty

happy with it, I may buy it again. The other tire I tried was the
Continental Top Touring. I found this tire to ride a bit harsh.

I would prefer a slick tire (without a tread pattern) because I think
the
inverted tread actually catches debris and may lead to more flats. I
also
don't believe that tread pattern does anything to improve wet or dry
grip
on the road. And I don't use my touring bike off-road.


While a slick tire would certain improve traction on dry roads ... I
don't
see why you think a tread won't improve wet road traction ... unless your
tire "contact point" is so small and your speed is so slow that you would
not hydroplane in puddles.


The rule developed for estimating when hydroplaning conditions exist for
landing planes which have smooth tires is that
V(mph) = 10 * tire pressure (psi).
Sorry, but I meant to write square root (tire pressure in psi), so at
100 psi the minimum speed would be 100 mph.

Since I generally run my tires at about 100 psi and keep my speed below
100 mph I satisfy your condition that the "contact point is so small and
your speed is so slow that you would not hydroplane."

In the automotive (and motorcycle) world the
main (if not the only) reason for tread in a street tire is for wet
weather
use.


With tire pressures around 30 psi and speeds over 55 mph hydroplaning
becomes a serious problem.

wrote:

Richard Amirault wrote:

"Don DeMair" wrote ...

I'm looking for a good touring tire. One that will be puncture
resistant, especially in the rain. I've tried the Specialized
Armadillo and was
pretty

happy with it, I may buy it again. The other tire I tried was the
Continental Top Touring. I found this tire to ride a bit harsh.

I would prefer a slick tire (without a tread pattern) because I think
the inverted tread actually catches debris and may lead to more flats.
I also don't believe that tread pattern does anything to improve wet or
dry grip on the road. And I don't use my touring bike off-road.

While a slick tire would certain improve traction on dry roads ... I
don't see why you think a tread won't improve wet road traction
... unless your tire "contact point" is so small and your speed is so
slow that you would not hydroplane in puddles.

The rule developed for estimating when hydroplaning conditions exist for
landing planes which have smooth tires is that
V(mph) = 10 * tire pressure (psi).

Since I generally run my tires at about 100 psi and keep my speed below
100 mph I satisfy your condition that the "contact point is so small and
your speed is so slow that you would not hydroplane."

In the automotive (and motorcycle) world the main (if not the only)
reason for tread in a street tire is for wet weather use.

With tire pressures around 30 psi and speeds over 55 mph hydroplaning
becomes a serious problem.

I hope you're not suggesting that this formula, which has no term for tire
width, is equally applicable to bicycles.

--
Benjamin Lewis

A small, but vocal, contingent even argues that tin is superior, but they
are held by most to be the lunatic fringe of Foil Deflector Beanie science.

David Damerell wrote in message ...
Big deal. If you told us you'd rode along the flat at 70mph and jumped to
the moon, that would be physically impossible too.

I experienced aquaplaning whilst riding a bicycle.

No, you didn't. A total loss of wheel traction on a single-track vehicle
will result in an immediate sideways fall.

I would like a qualification on why when a wheel loses traction, an
experienced rider on a properly set up bike riding in a race position would
most definitely fall.
Balance is still maintained with steering effort. Direction is deviated by
the fall of the road.
Faith, placed in the FAQ, over first hand experience and an enquiring
mind is what I find incredulous.
I expect with 90% certainty that the above mentioned poster would select
heads on a toss of a coin when it had shown six times on tails. Even though
all the evidence directs him to bet on tails, he bets heads because
probability shows that the toss of a coin will even out in the end. He
misunderstands that he is betting on one instance and so theoretically is an
even chance. The evidence before his own eyes he uses negatively in his
determination as it does not satisfy knowledge passed by others and his own
limited experience. As he fails to examine the coin he puts it down to an
unlucky streak. The coin could be double sided tails.
The rebuke has no reasoning, it is invalid. Repetition is not
acceptable evidence. I appears the poster has not experienced front wheel
lock-up and is unable to accept that the experiences of others may be
different than his own. his judgement on testimony, evidence and reasoning
is obviously poor.

TJ

Trevor Jeffrey wrote:


David Damerell wrote in message
...
Big deal. If you told us you'd rode along the flat at 70mph and jumped
to the moon, that would be physically impossible too.

I experienced aquaplaning whilst riding a bicycle.

No, you didn't. A total loss of wheel traction on a single-track vehicle
will result in an immediate sideways fall.

I would like a qualification on why when a wheel loses traction, an
experienced rider on a properly set up bike riding in a race position
would most definitely fall. Balance is still maintained with steering
effort.

"Steering effort" accomplishes nothing in the absence of traction.

Direction is deviated by the fall of the road. Faith, placed in
the FAQ, over first hand experience and an enquiring mind is what I find
incredulous. I expect with 90% certainty that the above mentioned poster
would select heads on a toss of a coin when it had shown six times on
tails.

Nice strawman. I expect with 100% certainty that this particular poster is
well aware that the probability of heads appearing is 0.5, assuming a
fair coin.

--
Benjamin Lewis

A small, but vocal, contingent even argues that tin is superior, but they
are held by most to be the lunatic fringe of Foil Deflector Beanie science.

Benjamin Lewis wrote:

wrote:


Richard Amirault wrote:


"Don DeMair" wrote ...


I'm looking for a good touring tire. One that will be puncture
resistant, especially in the rain. I've tried the Specialized
Armadillo and was

pretty


happy with it, I may buy it again. The other tire I tried was the
Continental Top Touring. I found this tire to ride a bit harsh.

I would prefer a slick tire (without a tread pattern) because I think
the inverted tread actually catches debris and may lead to more flats.
I also don't believe that tread pattern does anything to improve wet or
dry grip on the road. And I don't use my touring bike off-road.

While a slick tire would certain improve traction on dry roads ... I
don't see why you think a tread won't improve wet road traction
... unless your tire "contact point" is so small and your speed is so
slow that you would not hydroplane in puddles.

The rule developed for estimating when hydroplaning conditions exist for
landing planes which have smooth tires is that
V(mph) = 10 * Sq. Root[tire pressure (psi)].

Since I generally run my tires at about 100 psi and keep my speed below
100 mph I satisfy your condition that the "contact point is so small and
your speed is so slow that you would not hydroplane."


In the automotive (and motorcycle) world the main (if not the only)
reason for tread in a street tire is for wet weather use.

With tire pressures around 30 psi and speeds over 55 mph hydroplaning
becomes a serious problem.


I hope you're not suggesting that this formula, which has no term for tire
width, is equally applicable to bicycles.

It has no term for the width of the tire since that was determined to
not affect the critical speed for the onset of hydroplaning. The
formula is used for planes ranging from 767 size and up down to little
Cessna 150s and I don't see any particular reason why you'd expect it
not to apply to bicycle tires. Both planes and road bicycles use tires
that have a round cross-section and little tread. Until you get down to
a size where surface tension and similar effects become significant I'd
expect both types of tire to show the same tendencies wrt hydroplaning
vs. speed and pressure.

Trevor Jeffrey wrote:
I experienced aquaplaning whilst riding a bicycle. The speed was
approx. 40mph, on a decline with 20-25mm standing water. Tyre section was
25-28mm, pressure 90psi tyres were most probably Michelin HI-LITES 700x25c
rim Super Champion Mixte.
Treaded tyres of the same construction and materials have an enhanced
grip, in the wet, over their otherwise similar non-treaded brethren. The
raised portion of the tread gives a higher pressure contact patch than is
possible with a bald tyre. The regions of high pressure force the water
between the road surface and the tyre to migrate to the areas of low
pressure thus allowing the tyre to contact the road and provide stiction.
Directional stability of the wheel is assured in usual wet conditions due to
the tyre contact patch being of good length.
In order for a bald tyre to function in the wet, extreme inflation
pressure is required to attempt to match the penetrative qualities of a
treaded tyre with its associated regions of high pressure. The extreme
inflation pressure shortens the tyre contact patch to a length where
insufficient lateral stability of the tyre is available resulting in
skittish behaviour in the dry and sideslip in the wet though corners. The
above is assuming a nominal wheel diameter of 27", riders of 48" wheels and
above may find adequacy in bald, hard and narrow tyres.
Lower inflation pressures are also more comfortable, which translates
to less rider stress, which allows greater mileage and speed per ride, per
period, per season.
TJ


Have you read the FAQ? See

http://draco.acs.uci.edu/rbfaq/FAQ/8b.13.html

as well as other entries.


--
Todd Bryan
Santa Barbara, CA
bryan at cs dot utk dot edu

On Fri, 30 Jul 2004 10:31:10 -0700, Peter
wrote:

[snip]

The rule developed for estimating when hydroplaning conditions exist for
landing planes which have smooth tires is that
V(mph) = 10 * tire pressure (psi).
Sorry, but I meant to write square root (tire pressure in psi), so at
100 psi the minimum speed would be 100 mph.

Since I generally run my tires at about 100 psi and keep my speed below
100 mph I satisfy your condition that the "contact point is so small and
your speed is so slow that you would not hydroplane."

In the automotive (and motorcycle) world the
main (if not the only) reason for tread in a street tire is for wet
weather
use.


With tire pressures around 30 psi and speeds over 55 mph hydroplaning
becomes a serious problem.



Dear Peter,

I'm curious about the tire pressure and the plane formula.

Am I right in thinking that the lift of the plane at such
speeds is what makes its tire pressure so important in
hydroplaning?

That is, a plane just landing puts much less weight on its
tires than it does when parked because its wings are still
generating lift, so the contact patch would increase
considerably as the aircraft slowed down, something that
doesn't occur with bicycles.

I'm really just wondering whether the two situations are
similar enough to compare if the airplane effectively
becomes heavier and heavier as it slows down, while the
bicycle stays the same.

Carl Fogel

"Trevor Jeffrey" wrote in
:

Faith, placed in the FAQ, over first hand experience and an
enquiring
mind is what I find incredulous.
I expect with 90% certainty that the above mentioned poster would
select
heads on a toss of a coin when it had shown six times on tails. Even
though all the evidence directs him to bet on tails, he bets heads
because probability shows that the toss of a coin will even out in the
end. He misunderstands that he is betting on one instance and so
theoretically is an even chance. The evidence before his own eyes he
uses negatively in his determination as it does not satisfy knowledge
passed by others and his own limited experience. As he fails to
examine the coin he puts it down to an unlucky streak. The coin could
be double sided tails.
The rebuke has no reasoning, it is invalid. Repetition is not
acceptable evidence. I appears the poster has not experienced front
wheel lock-up and is unable to accept that the experiences of others
may be different than his own. his judgement on testimony, evidence
and reasoning is obviously poor.

And extraordinary claims require extraordinary proof. You're the one
claiming you experienced hydroplaning on a bike.

Maybe it would help advance the discussion if you went into more detail
about that? You've mentioned what you think the water depth was, and
your speed. What happened to the bike? Did your rear wheel suddenly
start spinning faster? Did you brake and lock the front wheel while
still moving forward in a straight line? Did you slide out of control?
What led you to think you were hydroplaning?

One reason I'm skeptical is that loss of traction can be caused by many
things, like dirt and other materials mixed with water. The streets in
my neighborhood are extra slippery in the first half hour or so of
rainfall after an extended dry spell. The accumulated dust, vehicle oil
drops and water combine to make an emulsion film on the road. I notice
this when driving a car as well as a bike, and I'm a extra careful when
braking even at low speeds. It has nothing to do with hydroplaning.

If I was riding down a hill and hit a flat spot with a thin film of
water and lost traction, I'm not sure I'd automatically assume this was
hydroplaning, unless all the other possibilities were definitely ruled
out.

--
Mike Barrs