Road tire life span

wrote:

wrote:

Tire testing machinery is important in this business and as far as I
can tell no one has one other than Avocet, a company that is not
currently performing such tests.

While most of what you wrote makes sense, your closing
sentence puzzles me.

If "tire testing machinery is important in this business,"
why does only one company have it--and not currently use it?

Is there a difference between "should be important" and "is important"?
(Not a rhetorical question. I think it depends on how you define
"important".)

--
Benjamin Lewis

I regret to say that we of the FBI are powerless to act in cases of
oral-genital intimacy, unless it has in some way obstructed interstate
commerce. -- J. Edgar Hoover

Carl Fogel writes:

Tire testing machinery is important in this business and as far as
I can tell no one has one other than Avocet, a company that is not
currently performing such tests.

While most of what you wrote makes sense, your closing sentence
puzzles me.

If "tire testing machinery is important in this business," why does
only one company have it--and not currently use it?

Because I don't work for these companies and designed the machine for
Avocet at a time when I encouraged them to introduce slick tread
tires. Their question was, "how can we convince people they won't
crash with them?"

http://tinyurl.com/2gbsj

My response was the test bed and the machine, plus the picture of the
tire in action. You apparently don't recall how extreme the
resistance to smooth tread was at the time. We may have gotten over
that now but it could always return if Continental, for instance, put
on a big advertising effort to sell a new tread pattern. People
forget.

When you wrote "business," did you perhaps mean the topic of the
thread and not the actual business of the Avocet company?

What means this? Please clarify.

Jobst Brandt

Benjamin Lewis writes:

Tire testing machinery is important in this business and as far as
I can tell no one has one other than Avocet, a company that is not
currently performing such tests.

While most of what you wrote makes sense, your closing sentence
puzzles me.

If "tire testing machinery is important in this business," why does
only one company have it--and not currently use it?

Is there a difference between "should be important" and "is
important"? (Not a rhetorical question. I think it depends on how
you define "important".)

That depends on whether you think traction is an important parameter.
Currently, those who make colored treads do not think so or they
wouldn't send people out in wet weather on their tires. A quick run
on a testing machine would reveal how these tire track in wet and dry
in short order and they could be compared against some standard carbon
black tread tire.

That for me falls into the definition "is important". How can this
not be important to a tire manufacturer?

Jobst Brandt

On Tue, 22 Jun 2004 03:44:40 GMT,
wrote:

Carl Fogel writes:

Tire testing machinery is important in this business and as far as
I can tell no one has one other than Avocet, a company that is not
currently performing such tests.

While most of what you wrote makes sense, your closing sentence
puzzles me.

If "tire testing machinery is important in this business," why does
only one company have it--and not currently use it?

Because I don't work for these companies and designed the machine for
Avocet at a time when I encouraged them to introduce slick tread
tires. Their question was, "how can we convince people they won't
crash with them?"

http://tinyurl.com/2gbsj

My response was the test bed and the machine, plus the picture of the
tire in action. You apparently don't recall how extreme the
resistance to smooth tread was at the time. We may have gotten over
that now but it could always return if Continental, for instance, put
on a big advertising effort to sell a new tread pattern. People
forget.

When you wrote "business," did you perhaps mean the topic of the
thread and not the actual business of the Avocet company?

What means this? Please clarify.

Jobst Brandt


Dear Jobst,

I was just trying to figure out why you seemed to be saying
that tire testing machinery is important in this [tire
manufacturing?] business, but then apparently saying that
only one company thinks that it's important enough to have
such machinery and isn't even using it at present.

This seems to be the familiar picture of you in a corner:

http://tinyurl.com/2gbsj

Are there any pictures of the machine in use?

Thanks,

Carl Fogel

jobst brandt wrote:

Benjamin Lewis writes:

Is there a difference between "should be important" and "is
important"? (Not a rhetorical question. I think it depends on how
you define "important".)

That depends on whether you think traction is an important parameter.
Currently, those who make colored treads do not think so or they
wouldn't send people out in wet weather on their tires. A quick run
on a testing machine would reveal how these tire track in wet and dry
in short order and they could be compared against some standard carbon
black tread tire.

That for me falls into the definition "is important". How can this
not be important to a tire manufacturer?

Selling tires is important to tire manufacturers. Why would improving
traction be important to them if consumers don't demand it, or believe
their claims without examining any data? The goodness of their hearts?

--
Benjamin Lewis

I regret to say that we of the FBI are powerless to act in cases of
oral-genital intimacy, unless it has in some way obstructed interstate
commerce. -- J. Edgar Hoover

wrote:
That depends on whether you think traction is an important parameter.
[...]
That for me falls into the definition "is important". How can this
not be important to a tire manufacturer?

That is where engineering and marketing divide, and many will
prioritize the latter as the market tends to reward it 8-/

--
MfG/Best regards
helmut springer

Hutchinson Carbon Comp tires. They wear very well, but still have good
fast
cornering characteristics (I use em in crits, but I'm only Cat 4, so we're
not cornering at 30+) and pliable enough (even at 140PSI) that on long
rides, I don't start cursing them out.

I also use Hutchinson Carbon Comp tires on my competition wheels. They have
been on for nearly three seasons now and probably run about 1500 miles. I've
not had any flats so far (knock on wood) besides the one I made when I put
them on for the first time (quite tight fit on Shimano wheels). These are
the only clinchers I've used so cannot say anything about other brands. By
the way I got a flat on my front tubular this morning. A real bang going at
35 mph. Luckily the glue kept it on.
Hjalmar

Rick Onanian writes:

Your paved-drum/leaned-bike experiment sounds like a reasonable,
if imperfect, test method for fictional roads made of perfectly
clean and perfectly flat pavement. I rarely find roads like that,
and when I do, the new-pavement fumes make riding somewhat
unpleasant.

Maybe you can explain what is "imperfect about this test.

The shape of the contact patch is different; the tire must conform
to the drum's convex shape. Further, it sure sounds like a perfect
surface, unlike a road surface, which is rarely so.

I think you'll find that a six foot diameter is adequate to
approximate a road for test purposes, considering the contact patch
length of a normally inflated tire. Besides, this is a comparative
test and the values it produced are repeatable and close enough from
road values for side slip that one cannot readily see a difference.

What is it that the drum diameter obscures?

I have experienced such slips often and even done so crossing
smooth paint stripes in the rain, but I don't attribute those
incidents to the tire but rather to sand on the road or a slick
wet spot. We ARE talking about handling ability of one tire over
another.

Yes, but what good is it to know the handling ability on perfect
pavement when we don't ride on such surfaces? We ride on roads
with a bit of sand or a slick wet spot. Knowing the handling
ability of a tire for such conditions is immensely more useful.

Let's not get into philosophy.

What philosophy? I ride on real roads, with imperfect pavement,
sometimes with sand or a slick wet spot. If a tire can't give a
little and let me know before I suddenly find it airborne (and my
body grounded), I want the BEST handling tire I can get.

Perfection is philosophical. Besides, if you cannot control the test
conditions you cannot perform the test. What you are suggesting is
that such tests cannot be performed because roads vary too much. Such
tests are performed on standardized conditions that give typical best
values. The user must estimate what degraded conditions he is
encountering that will give poorer results, such as loose gravel, oil,
slick spots and the like.

You claim to have slid tires on clean dry pavement and I said that
is not a recoverable condition so it

I claim to have slid tires on real pavement. I doubt it was
perfectly clean, and I doubt it was perfectly flat, although I
didn't feel bumps.

Lets get away for your definition of "real pavement" and use pavement
like that in the picture I attached:

http://tinyurl.com/2gbsj

I think that is real enough and Pescadero Road has a few of these
curves with "real" pavement at about 40mph.

I'm sure you didn't slip in a curve when banked over at near 45
degrees because that is unrecoverable. What were the circumstances
and what was the speed.

cannot be the criterion for handling among different tires. We
generally don't ride beyond the limit of traction so the criterion
must be something else. I'm trying to get to the bottom of how you can
give comparative ratings to tires of similar size, inflation and
essentially smooth tread.

I don't know how it can be done. IANAE. Something more realistic
than a paved drum may be in order.

Again, what is it about a drum that you find deficient? It is the
common way tires are laboratory tested.

Well, then we're not talking about a lot of precision here. Wheel
imbalance can bounce a bike up and down in my hand at 20mph; that
lifting/weighting force must affect the tire's load (and therefore,
contact patch) each revolution.

I doubt that.

Which part do you doubt? That the wheel can bounce the hand-held
bike at 20mph, or that such a force must affect the tire's
connection to the road?

Both. As I have explained at length.

The first part can be tested by holding the rear of the bike a foot
off the ground, and using the other hand to pedal it up as fast as
you can. Mine provides a definite up-and-down motion, which I
experimentally corrected by balancing the wheel.

THAT is an unrealistic test.

Having descended at more than 50mph often without having balanced
wheels, I have not felt so much as a hint of imbalance from my
conventional wheels that are not balanced. Besides that, as I

I've never passed 45mph, but even at that speed, I either did not
feel imbalance or wouldn't know it from road vibration.

A rider can tell if he got through his favorite curve (which has
real-world pavement) at a higher speed without any traction
reduction.

Yes? How do you determine "traction reduction". This is what is
at the root of this subject and I propose that you cannot sense
this without exceeding the limit and crashing. Therefore, claiming
that one tire handles better than another is an undefined
subjective claim.

I don't know how you determine it. I agree that such a claim would
be subjective.

I know what it is and have crashed as well as having measured it the
test equipment I have described. I don't think you have the
information to make the suppositions you do.

I repeat, you didn't slip on clean dry pavement. I don't claim that
you didn't slip but it was for some reason other than traction
limitation of the tire. It was more likely some foreign object on the
road or a spot of some lubricant.

Like I said, real world road. Not a testing machine in a lab. I
can't imagine how it could be tested.

Are you implying that the scene in the attached URL is not real world.
I ride around that curve in that manner often as I do with many other
curves. I also have piles of tires I have worn to the cords as well
as rims on which they served. There are a lot of test miles
accumulated.

I think you need to get out of your "real world" pavement and get to
reality.

Jobst Brandt

Benjamin Lewis writes:

Selling tires is important to tire manufacturers. Why would
improving traction be important to them if consumers don't demand
it, or believe their claims without examining any data? The
goodness of their hearts?

Preventing expensive lawsuits? What the tire manufacturers are
banking on is that the vast majority of bike riders just want to look
like they could go fast, rather than actually going fast and operating
the equipment at the limits of functionality. These people never
remotely approach the margins of safety.

People like Jobst- and perhaps you- who live near and frequently ride
in mountains push the equipment much closer to the limits than I do,
living as I do in flat to rolling terrain and no longer racing. To
those folks, whose health and possibly survival is dependent on the
equipment functioning properly, traction is a rather important feature
in a bike tire. I was much more aware of traction as an issue two
summers ago when I rode in the Alps, riding tight corners with long
drops to the outside; in the Minneapolis-St. Paul area there is just
nothing at all like that. Stopping traction is more important for
avoiding getting mashed by some latte-swilling SUV driver yakking on
their damned cell phone.

wrote in message
...
I know what it is and have crashed as well as having measured it the
test equipment I have described.

Jobst,
I have yet to see a cyclist crash or go down on DRY payment when leaning too
far into a turn.
I have a crash on wet payment as in the case of Jan Ulrich in last year's
Tour de France.

Is there a warning when you lean too far over in a turn that would be
unrecoverable and result in a crash.
Is it possible to recover if you have leaned too far over in a turn?

I'll have to say, you have a lot of guts to even attempt this test. I could
probably attempt this with full leathers and a full face motorcycle helmet.
-tom