Road tire life span

[cheg]

I have been running Conti Ultra Gatorskins on my road bike and lost the front
one to a sidewall blowout last week. I noticed that he rear tire is worn through
most of the tread pattern after about 1400 miles so I replaced them both. Is
that a reasonable life span for quality tires? I'm curious how often people
normally replace tires.

[Arthur Clune]

cheg > wrote:
: I have been running Conti Ultra Gatorskins on my road bike and lost the front
: one to a sidewall blowout last week. I noticed that he rear tire is worn through
: most of the tread pattern after about 1400 miles so I replaced them both. Is
: that a reasonable life span for quality tires? I'm curious how often people
: normally replace tires.

How much do you weight, what width are the tyres and to what pressure do you
inflate them?


--
Arthur Clune http://www.clune.org
"Technolibertarians make a philosophy out of a personality defect"
- Paulina Borsook

[David L. Johnson]

On Wed, 16 Jun 2004 12:52:46 +0000, cheg wrote:

> I have been running Conti Ultra Gatorskins on my road bike and lost the front
> one to a sidewall blowout last week. I noticed that he rear tire is worn through
> most of the tread pattern after about 1400 miles so I replaced them both. Is
> that a reasonable life span for quality tires? I'm curious how often people
> normally replace tires.

I consider that pretty poor. I avoid Continentals since they do seem
prone to sidewall failures. There will be some who say that they have
never had one, and that may be, but damn near all the people I*encounter
on the road with the sidewall blown out have been on Contis.

On the other hand, "tread" wear is not an indication of tire wear for road
bikes. Since the tread does not do anything useful, it is of no
consequence when it is worn off. Tires are worn out when the casing
begins to show through. For me, with my Avocet tires, this happens
somewhere around 3000-4000 miles on the rear, and never on the front
(since I move the front to the rear when the rear is worn out).

--

David L. Johnson

__o | Do not worry about your difficulties in mathematics, I can assure
_`\(,_ | you that mine are all greater. -- A. Einstein
(_)/ (_) |

[Tom Nakashima]

"David L. Johnson" > wrote in message
...
> On Wed, 16 Jun 2004 12:52:46 +0000, cheg wrote:
>
> > I have been running Conti Ultra Gatorskins on my road bike and lost the
front
> > one to a sidewall blowout last week. I noticed that he rear tire is worn
through
> > most of the tread pattern after about 1400 miles so I replaced them
both. Is
> > that a reasonable life span for quality tires? I'm curious how often
people
> > normally replace tires.
>
> I consider that pretty poor. I avoid Continentals since they do seem
> prone to sidewall failures. There will be some who say that they have
> never had one, and that may be, but damn near all the people I encounter
> on the road with the sidewall blown out have been on Contis.
>
> On the other hand, "tread" wear is not an indication of tire wear for road
> bikes. Since the tread does not do anything useful, it is of no
> consequence when it is worn off. Tires are worn out when the casing
> begins to show through. For me, with my Avocet tires, this happens
> somewhere around 3000-4000 miles on the rear, and never on the front
> (since I move the front to the rear when the rear is worn out).
>
> --
>
> David L. Johnson
>
> __o | Do not worry about your difficulties in mathematics, I can
assure
> _`\(,_ | you that mine are all greater. -- A. Einstein
> (_)/ (_) |
>
When I was commuting I used to wear the rear tire out pretty fast, also
riding Avocet tires. Most of my commute was flat. After about 2,500 miles
the middle of the tire would be pretty square. After 1000 miles, I would
switch the front with the rear. Now that I'm riding a lot of hills and
cornering on the descents, my tires are rounded and have a longer life.
-tom

[Dave]

Depends on the tire characteristics, your riding style, road surface
material and climate, just like car tires. Grippier tires will wear earlier
because of the softer compound. Hot climate will certainly wear tires
faster; if you do a lot of hard pedaling or fast club rides, chances are
you're putting more road friction on the tires, and for example, here in S
Florida, many of the road surfaces we ride on have hard coral mixed into the
asphalt, so it can be harder on tires too. You need to look at what you're
doing to your tires.

BTW, 1400 miles is not bad wear for a set of tires, again depending on the
conditions. If you had said 400 miles, I'd have really wondered. I like
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.

Hope this helped....

Dave

"cheg" > wrote in message
news:yoXzc.30825$Hg2.5878@attbi_s04...
> I have been running Conti Ultra Gatorskins on my road bike and lost the
front
> one to a sidewall blowout last week. I noticed that he rear tire is worn
through
> most of the tread pattern after about 1400 miles so I replaced them both.
Is
> that a reasonable life span for quality tires? I'm curious how often
people
> normally replace tires.
>
>

[Tim McNamara]

"cheg" > writes:

> I have been running Conti Ultra Gatorskins on my road bike and lost
> the front one to a sidewall blowout last week. I noticed that he
> rear tire is worn through most of the tread pattern after about 1400
> miles so I replaced them both. Is that a reasonable life span for
> quality tires? I'm curious how often people normally replace tires.

Rear tires, usually about 3,000 miles or so. Front tires, about
20,000 miles or more. Eventually the sidewalls sort of dry rot so
it's a good idea to rotate tires IMHO. I replace the rear tire with
the front one, and put a new tire on the front wheel.

[Tim McNamara]

"Dave" > writes:

> BTW, 1400 miles is not bad wear for a set of tires, again depending
> on the conditions. If you had said 400 miles, I'd have really
> wondered. I like Hutchinson Carbon Comp tires. They wear very well

Thanks for the recommendation. I'll avoid these if 1400 miles is
"good" wear. Yikes.

[Rick Onanian]

On Wed, 16 Jun 2004 17:44:09 -0500, Tim McNamara
> wrote:
>"Dave" > writes:
>> BTW, 1400 miles is not bad wear for a set of tires, again depending
>> on the conditions. If you had said 400 miles, I'd have really
>> wondered. I like Hutchinson Carbon Comp tires. They wear very well
>
>Thanks for the recommendation. I'll avoid these if 1400 miles is
>"good" wear. Yikes.

I like Carbon Comps, but I'm under no illusion as to their wear. I
wore a rear in 600 miles.
--
Rick Onanian

[Benjamin Lewis]

Tim McNamara wrote:

> "Dave" > writes:
>
>> BTW, 1400 miles is not bad wear for a set of tires, again depending
>> on the conditions. If you had said 400 miles, I'd have really
>> wondered. I like Hutchinson Carbon Comp tires. They wear very well
>
> Thanks for the recommendation. I'll avoid these if 1400 miles is
> "good" wear. Yikes.

Indeed. I currently have about 7000 km (about 4300 miles) on a pair of
Vittoria Randonneurs, and there's still a fair bit of rubber left even on
the rear; if I don't get another 3000 km I'll be surprised. These tires
are pretty thick to begin with, though. I'm sure they have a slight RR
penalty because of this, but I'd highly recommend them otherwise. I've had
two flats in this time, for what it's worth.

--
Benjamin Lewis

The majority of the stupid is invincible and guaranteed for all time. The
terror of their tyranny, however, is alleviated by their lack of consistency.
-- Albert Einstein

[Bow]

I was on Conti Gatorskins until last month, and was getting about the same
performance on the rear tyre. I haven't had sidewall blowouts, but have had
tearing along the front wheel tread (those L shaped indents) that have been
so bad that the tube sticks out.

I have since gone back to Vittoria - just as good in my opinion, but cheaper
and easier to put on.

Regards

Bow
"Tim McNamara" > wrote in message
...
> "Dave" > writes:
>
> > BTW, 1400 miles is not bad wear for a set of tires, again depending
> > on the conditions. If you had said 400 miles, I'd have really
> > wondered. I like Hutchinson Carbon Comp tires. They wear very well
>
> Thanks for the recommendation. I'll avoid these if 1400 miles is
> "good" wear. Yikes.

[cheg]

"Arthur Clune" > wrote in message
...
> cheg > wrote:
> : I have been running Conti Ultra Gatorskins on my road bike and lost the
front
> : one to a sidewall blowout last week. I noticed that he rear tire is worn
through
> : most of the tread pattern after about 1400 miles so I replaced them both. Is
> : that a reasonable life span for quality tires? I'm curious how often people
> : normally replace tires.
>
> How much do you weight, what width are the tyres and to what pressure do you
> inflate them?


155 lbs, 32 mm, 110 psi.

[cheg]

"David L. Johnson" > wrote in message
...

> On the other hand, "tread" wear is not an indication of tire wear for road
> bikes. Since the tread does not do anything useful, it is of no
> consequence when it is worn off. Tires are worn out when the casing
> begins to show through. For me, with my Avocet tires, this happens
> somewhere around 3000-4000 miles on the rear, and never on the front
> (since I move the front to the rear when the rear is worn out).
>

Then I'll hang on to the one I took off the rear. It probaby has another couple
of thousand miles in it. The sidewall must have been damaged, I hope so anyway,
but that is the first time I ever exploded a tire with a frame pump. I should
probably get a folding tire to carry on long rides just in case.

[cheg]

"Dave" > wrote in message
...
> Depends on the tire characteristics, your riding style, road surface
> material and climate, just like car tires. Grippier tires will wear earlier
> because of the softer compound. Hot climate will certainly wear tires
> faster; if you do a lot of hard pedaling or fast club rides, chances are
> you're putting more road friction on the tires, and for example, here in S
> Florida, many of the road surfaces we ride on have hard coral mixed into the
> asphalt, so it can be harder on tires too. You need to look at what you're
> doing to your tires.
>
> BTW, 1400 miles is not bad wear for a set of tires, again depending on the
> conditions. If you had said 400 miles, I'd have really wondered. I like
> 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.
>
> Hope this helped....
>

This is in Seattle, certainly not a hot climate by your standards. We have hills
instead :-)

The compound of the Ultra Gatorskins does seem softer than other tires I've
used. I don't ride particularly fast, though. I average about 200 miles a week,
mostly commuting in the 15-17 mph range.

[Dave]

Wow. 600 miles? I used mine for about 300 miles to break them in for the
Cross Florida Race (a 170 miler) this year, in April, and have put on about
another 1000 since then, and no sign of a flat spot developing at all on the
rear wheel....



"Rick Onanian" > wrote in message
...
> On Wed, 16 Jun 2004 17:44:09 -0500, Tim McNamara
> > wrote:
> >"Dave" > writes:
> >> BTW, 1400 miles is not bad wear for a set of tires, again depending
> >> on the conditions. If you had said 400 miles, I'd have really
> >> wondered. I like Hutchinson Carbon Comp tires. They wear very well
> >
> >Thanks for the recommendation. I'll avoid these if 1400 miles is
> >"good" wear. Yikes.
>
> I like Carbon Comps, but I'm under no illusion as to their wear. I
> wore a rear in 600 miles.
> --
> Rick Onanian

[Dave]

Point is, many Conti models are not known for long life. The 3000's wear in
about 200 miles or less around here (a buddy of mine rides em...)


"Tim McNamara" > wrote in message
...
> "Dave" > writes:
>
> > BTW, 1400 miles is not bad wear for a set of tires, again depending
> > on the conditions. If you had said 400 miles, I'd have really
> > wondered. I like Hutchinson Carbon Comp tires. They wear very well
>
> Thanks for the recommendation. I'll avoid these if 1400 miles is
> "good" wear. Yikes.

[cheg]

"Russell Seaton" > wrote in message
om...
> "cheg" > wrote in message
news:<yoXzc.30825$Hg2.5878@attbi_s04>...
> > I have been running Conti Ultra Gatorskins on my road bike and lost the
front
> > one to a sidewall blowout last week. I noticed that he rear tire is worn
through
> > most of the tread pattern after about 1400 miles so I replaced them both. Is
> > that a reasonable life span for quality tires? I'm curious how often people
> > normally replace tires.
>
> That is awful mileage. I have used 700Cx23mm Continental Ultra
> Gatorskin tires on one set of wheels since August 2001. In that time
> they have ridden across North Dakota, North Carolina, Wisconsin,
> Colorado, and Kansas. Plus a couple 200km brevets and one or maybe
> two 300km brevets. Plus a few training miles. Probably 4,000 total
> miles. Give or take. Front looks fine. Rear is squared off a bit
> but not too bad. My Gatorskin tires have some extra strong coating on
> the sidewalls to reduce cuts significantly. I weigh 200 pounds.

The tires say "Duraskin K" on them but the sidewalls seem very thin and flexible
compared to the Specialized tires I've used in the past.

[Dave]

"Dave" > wrote in message
...
> Point is, many Conti models are not known for long life. The 3000's wear
in
> about 200 miles or less around here (a buddy of mine rides em...)
>
>
> "Tim McNamara" > wrote in message
> ...
> > "Dave" > writes:
> >
> > > BTW, 1400 miles is not bad wear for a set of tires, again depending
> > > on the conditions. If you had said 400 miles, I'd have really
> > > wondered. I like Hutchinson Carbon Comp tires. They wear very well
> >
> > Thanks for the recommendation. I'll avoid these if 1400 miles is
> > "good" wear. Yikes.
>
>

[James Scott]

cheg wrote:

> Then I'll hang on to the one I took off the rear. It probaby has another couple
> of thousand miles in it. The sidewall must have been damaged, I hope so anyway,
> but that is the first time I ever exploded a tire with a frame pump. I should
> probably get a folding tire to carry on long rides just in case.

Stick a dollar bill or a small piece of plastic milk jug in your
saddlebag and wrap some duct tape around your pump body. Those all make
excellent tire boots. The duct tape is my favorite, since it's a
multi-purpose repair material.


JLS
--
James "Be prepared" Scott
www.jls.cx

[David Damerell]

James Scott > wrote:
>Stick a dollar bill or a small piece of plastic milk jug in your
>saddlebag and wrap some duct tape around your pump body. Those all make
>excellent tire boots.

So does a length of an old tyre with the bead cut off, FWIW.
--
David Damerell > flcl?

[Matt O'Toole]

cheg wrote:

> I have been running Conti Ultra Gatorskins on my road bike and lost
> the front one to a sidewall blowout last week. I noticed that he rear
> tire is worn through most of the tread pattern after about 1400 miles
> so I replaced them both. Is that a reasonable life span for quality
> tires? I'm curious how often people normally replace tires.

A normal life span is at least 2000, and probably closer to 3000 miles, for
modern, road-race-oriented tires. Durability-oriented tires last longer than
that, but may not be as fast or smooth.

Some tires have very thin tread, in the interests of low weight and rolling
resistance. But this kind of gram-shaving is silly -- some of the fastest tires
are also the most durable. Note the RR and durablity results cited for Avocets,
for example.

With all the touble people seem to have with Continentals, I don't understand
why they continue to buy them. I see Contis with frayed sidewalls all the time,
held together with Shoe Goo. Thse people ride the same roads as I do, and I
never have tire trouble.

I've been very happy with the Vittoria Open Corsa CX. They came with my bike,
and I thought they were fragile race tires that I'd wear out or destroy soon.
This has proven not to be the case. I have about 2000 miles on them now, with
just one puncture, no cuts, and the rear is just starting to square off. They
look like they'll go another 500-1000 miles. They're some of the best riding,
fastest tires I've ever used. No problems in the wet either. It's very hilly
around here, with lots of rough pavement, which can be hard on tires. I'd
definately buy the Vittorias again, but only on sale (they're expensive).

My friend uses Hutchinson Carbon Comps, and gets maybe 2000 miles out of them.
But he buys them on sale for under $20 each. Nashbar has had some pretty good
tires on sale lately for as little as $10-15 -- Panaracer, etc. If your tires
will be destroyed by cuts anyway, it probably makes no sense to pay for extra
tread life.

Michelin Carbon are advertised as durable and cut resistant, as well as fast and
comfortable. 3500-4000 miles for $30-35, and widely available. Anyone using
these?

Matt O.

[Rick Onanian]

>"Rick Onanian" > wrote in message
>> I like Carbon Comps, but I'm under no illusion as to their wear. I
>> wore a rear in 600 miles.
On Wed, 16 Jun 2004 21:48:12 -0400, "Dave"
> top-posted:
>Wow. 600 miles? I used mine for about 300 miles to break them in for the
>Cross Florida Race (a 170 miler) this year, in April, and have put on about
>another 1000 since then, and no sign of a flat spot developing at all on the
>rear wheel....

I weigh 210 pounds and inflate to the max, 125psi. The roads I ride
aren't terribly dirty, nor terribly clean. I only flatted that tire
once (that I remember), after whacking a curb broke the presta
valve.

After 600 miles, there was a flat spot that may have been from when
I test rode the bike before buying; I had skidded a little bit
avoiding a car. The tread is riddled with very small cuts, and one
such cut was in the middle of said flat spot, and the tube pushed
through just enough to leak quickly.

I think, if I want to spend the time and effort, I can repair the
tire with various glues, liquid-applied rubbers, and patches/boots.
Some day, I might actually do it; I've kept the tire for that
purpose. I've got a collection of stuff with which to do it -- shoe
goo, rtv silicone gasket stuff, superglue, heavy-duty automotive
radial tire patches, contact cement, superglue, and so on.
--
Rick Onanian

[Bill Lloyd]

On 2004-06-17 08:52:40 -0700, (Russell Seaton) said:

> "cheg" > wrote in message
> news:<3N6Ac.117748$Ly.117073@attbi_s01>...
>> "Russell Seaton" > wrote in message
>> om...
>>> "cheg" > wrote in message
>> news:<yoXzc.30825$Hg2.5878@attbi_s04>...
>>>> I have been running Conti Ultra Gatorskins on my road bike and lost the
>> front
>>>> one to a sidewall blowout last week. I noticed that he rear tire is worn
>> through
>>>> most of the tread pattern after about 1400 miles so I replaced them both. Is
>>>> that a reasonable life span for quality tires? I'm curious how often people
>>>> normally replace tires.
>>>
>>> That is awful mileage. I have used 700Cx23mm Continental Ultra
>>> Gatorskin tires on one set of wheels since August 2001. In that time
>>> they have ridden across North Dakota, North Carolina, Wisconsin,
>>> Colorado, and Kansas. Plus a couple 200km brevets and one or maybe
>>> two 300km brevets. Plus a few training miles. Probably 4,000 total
>>> miles. Give or take. Front looks fine. Rear is squared off a bit
>>> but not too bad. My Gatorskin tires have some extra strong coating on
>>> the sidewalls to reduce cuts significantly. I weigh 200 pounds.
>>
>> The tires say "Duraskin K" on them but the sidewalls seem very thin and
>> flexible
>> compared to the Specialized tires I've used in the past.
>
> Yes the Continental Ultra Gatorskin tires say Duraskin K on the
> sidewall. I'm guessing its some kind of kevlar coating. It is much
> more durable than regular Continental sidewalls.
>
> Odd that in the old days bike tire companies would brag about how
> flexible their sidewalls were. They would say they used silk or 290
> strands of cotton or such things. And now thick unflexible sidewalls
> are in vogue.

Maybe for flat resistance, but not for the "goodness" of having stiff
sidewalls.

[Bill Lloyd]

On 2004-06-16 05:52:46 -0700, "cheg" > said:

> I have been running Conti Ultra Gatorskins on my road bike and lost the front
> one to a sidewall blowout last week. I noticed that he rear tire is
> worn through
> most of the tread pattern after about 1400 miles so I replaced them both. Is
> that a reasonable life span for quality tires? I'm curious how often people
> normally replace tires.

Contis are among the longest wearing tires, if you get the carbon black
ones. I'd regularly get 4000 miles on a super sport rear tire. Front
tire life is essentially infinite -- it could go 20,000 miles or more
but typically you'd blow a sidewall first.

I get maybe 3000 miles out of Vredesteins (the black ones), and maybe
2000-2500 out of Ritchey Race tires (the nylon ones, not the $60 "open"
ones which I don't like the handling of).

Your front wheel sidewall blowout was not due to wear -- you either hit
something, scrubbed it pretty good, or did something else.

To avoid the front tire staying on for 3 years and rotting, I usually
rotate the front tire to the back, once I wear out the rear. And I put
new tires on the front.

[Booker C. Bense]

-----BEGIN PGP SIGNED MESSAGE-----

In article <9p6Ac.65596$Sw.45018@attbi_s51>,
cheg > wrote:
>
>"Arthur Clune" > wrote in message
...
>> cheg > wrote:
>> : I have been running Conti Ultra Gatorskins on my road bike and lost the
>front
>> : one to a sidewall blowout last week. I noticed that he rear tire is worn
>through
>> : most of the tread pattern after about 1400 miles so I replaced them both. Is
>> : that a reasonable life span for quality tires? I'm curious how often people
>> : normally replace tires.
>>
>> How much do you weight, what width are the tyres and to what pressure do you
>> inflate them?
>
>
>155 lbs, 32 mm, 110 psi.
>
>

_ That seems really high for a tire that big and your weight.
Overinflating tires will wear them out faster, makes the ride
harser and generally has no positive benfits.

http://sheldonbrown.com/tires.html

is a good reference.

_ Booker C. Bense

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[Matt O'Toole]

Bill Lloyd wrote:

> Contis are among the longest wearing tires, if you get the carbon
> black ones.

How do you know which is which? Even the black ones have silica instead these
days, but with black coloring instead of gray or whatever.

Matt O.

[Tim McNamara]

"Dave" > writes:

> Point is, many Conti models are not known for long life. The 3000's
> wear in about 200 miles or less around here (a buddy of mine rides
> em...)

The 2000 mile correction make *far* more sense.

The Conti 3000's are made with a non-carbon based rubber, some sort of
silicon based rubber. This rubber usually gives lousy traction in the
rain, but makes up for it by wearing out much faster than carbon-based
rubber. As a bonus, silica-rubber tires usually cost more. You can
tell I think these are not good tires.

I use carbon rubber based tires, and as I said I usually get about
3000 miles to a rear tire. I weigh a stubborn 215 lbs. I suspect
that road surface quality and how much climbing you do affects tire
wear. I found that my rear tire wore much more quickly riding in the
Alps than on the short hills around the Minneapolis-St. Paul area.

[Arthur Clune]

cheg > wrote:

: 155 lbs, 32 mm, 110 psi.

I assume you mean 23mm here? If not, that's way too high pressure for 32mm tyres.
90 PSI max would be more suitable.

Arthur


--
Arthur Clune http://www.clune.org
"Technolibertarians make a philosophy out of a personality defect"
- Paulina Borsook

[cheg]

"Arthur Clune" > wrote in message
...
> cheg > wrote:
>
> : 155 lbs, 32 mm, 110 psi.
>
> I assume you mean 23mm here? If not, that's way too high pressure for 32mm
tyres.
> 90 PSI max would be more suitable.
>
> Arthur
>

No, it's 32 mm (27"x1-1/4" to be precise).

110 psi is too high in what sense? They are not uncomfortable to ride at that
pressure.

[cheg]

"Booker C. Bense"
tanford.edu> wrote in message
...
> -----BEGIN PGP SIGNED MESSAGE-----
>
> In article <9p6Ac.65596$Sw.45018@attbi_s51>,
> cheg > wrote:
> >
> >"Arthur Clune" > wrote in message
> ...

> >> How much do you weight, what width are the tyres and to what pressure do
you
> >> inflate them?
> >
> >
> >155 lbs, 32 mm, 110 psi.
> >
> >
>
> _ That seems really high for a tire that big and your weight.
> Overinflating tires will wear them out faster, makes the ride
> harser and generally has no positive benfits.
>
> http://sheldonbrown.com/tires.html
>
> is a good reference.


Why does higher pressure increase wear rate? As far as the ride, the smoothness
of the ride is the one notable thing about Gatorskins that makes me want to
continue using them so I don't find them harsh at all. According to Jobst
Brandt's measured data higher pressure = lower rolling resistance, which could
be considered a positive benefit. I don't know how significant the gain is
compared to aerodynamic drag and other mechanical losses, though.

[Booker C. Bense]

-----BEGIN PGP SIGNED MESSAGE-----

In article <CFrAc.70526$Sw.53538@attbi_s51>,
cheg > wrote:
>
>"Booker C. Bense"
tanford.edu> wrote in message
...
>> -----BEGIN PGP SIGNED MESSAGE-----
>>
>> In article <9p6Ac.65596$Sw.45018@attbi_s51>,
>> cheg > wrote:
>> >
>> >"Arthur Clune" > wrote in message
>> ...
>
>> >> How much do you weight, what width are the tyres and to what pressure do
>you
>> >> inflate them?
>> >
>> >
>> >155 lbs, 32 mm, 110 psi.
>> >
>> >
>>
>> _ That seems really high for a tire that big and your weight.
>> Overinflating tires will wear them out faster, makes the ride
>> harser and generally has no positive benfits.
>>
>> http://sheldonbrown.com/tires.html
>>
>> is a good reference.
>
>
>Why does higher pressure increase wear rate?

_ Less of the tire contacts the road.

> As far as the ride, the smoothness
>of the ride is the one notable thing about Gatorskins that makes me want to
>continue using them so I don't find them harsh at all.

_ I think there is a typo in your message since I can't find any
evidence that gatorskins come in 32mm width. For a 23mm width
tire and your weight, 110 is probably about right...

According to Jobst
>Brandt's measured data higher pressure = lower rolling resistance, which could
>be considered a positive benefit. I don't know how significant the gain is
>compared to aerodynamic drag and other mechanical losses, though.

_ My own philosophy is to keep the tire pressure as low as is
safe and avoids pinch flats. For me road comfort in a 3 or 4 hour
ride is much more important than speed.

_ Booker C. Bense




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[Pete Grey]

I ride Gatorskins in the winter, 700x25's around the same pressure, maybe
more like 115.
I get similar mileage from them, and I weigh in about 165lb.

My Conti GP 3000's only last about 1000mi in the summer months on my faster
bike.

I consider both of these reasonable, for the good ride and handling from the
Conti's.
I have had one (1) sidewall problem in using them for nearly 14 years now,
YMMV. I also consider that reasonable, I think Conti has gotten a bad rap
from a few of these cases being made public, I'd guess that other
manufacturers have had the same problem from time-to-time.

I've tried other longer-wearing tires a few times over the years, and I'm
not switching:-]

-pete

"cheg" > wrote in message
news:aG6Ac.103502$3x.15777@attbi_s54...
>
> "Dave" > wrote in message
> ...
> > Depends on the tire characteristics, your riding style, road surface
> > material and climate, just like car tires. Grippier tires will wear
earlier
> > because of the softer compound. Hot climate will certainly wear tires
> > faster; if you do a lot of hard pedaling or fast club rides, chances are
> > you're putting more road friction on the tires, and for example, here in
S
> > Florida, many of the road surfaces we ride on have hard coral mixed into
the
> > asphalt, so it can be harder on tires too. You need to look at what
you're
> > doing to your tires.
> >
> > BTW, 1400 miles is not bad wear for a set of tires, again depending on
the
> > conditions. If you had said 400 miles, I'd have really wondered. I
like
> > 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.
> >
> > Hope this helped....
> >
>
> This is in Seattle, certainly not a hot climate by your standards. We have
hills
> instead :-)
>
> The compound of the Ultra Gatorskins does seem softer than other tires
I've
> used. I don't ride particularly fast, though. I average about 200 miles a
week,
> mostly commuting in the 15-17 mph range.
>
>

[[email protected]]

Tom Chandler writes:

> It's too bad as the Open Corsas have typically been the nicest
> handling tires I've used, but they go away so quickly and they're so
> expensive that I'm looking for something else.

How do you whether one tire handles better than another since traction
is either there or not on pavement. There is no tire squeal or
side-slip although writers to this newsgroup sometimes describe their
cornering as drifting in curves. This does not occur. Besides that,
chip seal, the most abrasive, roads have poorer traction than concrete
or hot-mix asphalt roads.

http://www.ci.anchorage.ak.us/streets/chipsealprogram.cfm

Jobst Brandt

[[email protected]]

On Fri, 18 Jun 2004 22:31:38 GMT,
wrote:

>Tom Chandler writes:
>
>> It's too bad as the Open Corsas have typically been the nicest
>> handling tires I've used, but they go away so quickly and they're so
>> expensive that I'm looking for something else.
>
>How do you whether one tire handles better than another since traction
>is either there or not on pavement. There is no tire squeal or
>side-slip although writers to this newsgroup sometimes describe their
>cornering as drifting in curves. This does not occur. Besides that,
>chip seal, the most abrasive, roads have poorer traction than concrete
>or hot-mix asphalt roads.
>
>http://www.ci.anchorage.ak.us/streets/chipsealprogram.cfm
>
>Jobst Brandt


Dear Jobst,

Maybe Tom notices that the traction is "not there" on the
pavement more often with poorer handling tires?

It seems unlikely, but are you saying that no rider can tell
whether one tire handles better than another in terms of
traction?

Since you offer no answer, your hastily typed question "How
do you [?] whether one tire handles better than another . .
.." seems rhetorical.

So how do you tell if one tire handles better than another?

Carl Fogel

[[email protected]]

Carl Fogel writes:

>>> It's too bad as the Open Corsas have typically been the nicest
>>> handling tires I've used, but they go away so quickly and they're
>>> so expensive that I'm looking for something else.

>> How do you [know] whether one tire handles better than another
>> since traction is either there or not on pavement. There is no
>> tire squeal or side-slip, although writers to this newsgroup
>> sometimes describe their cornering as drifting in curves. This
>> does not occur. Besides that, chip seal, the most abrasive, roads
>> have poorer traction than concrete or hot-mix asphalt roads.

> Maybe Tom notices that the traction is "not there" on the
> pavement more often with poorer handling tires?

Maybe shmaybe, let the man speak for himself. You don't have to hold
his hand.

> It seems unlikely, but are you saying that no rider can tell whether
> one tire handles better than another in terms of traction?

Unless it is a knobby tire (not a road tire of the kind in question)
there is no perceptible difference in handling until is washes out in
a curve, something that occurs with colored tires on wet roads. It is
not something you prefer to test but it has been done both in situ and
on the tire testing machine I once designed for Avocet to measure
maximum lean angle for tires.

> Since you offer no answer, your hastily typed question "How
> do you [?] whether one tire handles better than another . .
> ." seems rhetorical.

That may be so in your estimation but I didn't ask you.

> So how do you tell if one tire handles better than another?

You test it on a machine. I originally performed such tests on a 16ft
long paved plywood tiltbed increasing the angle until the bicycle
slid. This was done at low speed and with protective clothing. There
was a difference among tires tested. That was a few years ago.

Jobst Brandt

[Ross]

My rear Conti GP 3000 got 5000 miles on it before I bought a new one. I put
the new one on the front and the front one on the rear, so now the rear has
6000 on it. I weigh 160 and ride in the Texas Hill country in San Antonio.
I'm a fanatic about keeping an eye on my bike and it's various wears and
tears and only replaced the rear when it got that flattened out look. Upon
removal I checked the rubber remaining by just feeling it and while there
was a difference (obviously) from the new tire to the old one, the old one
had worn pretty regular.

Ross


"Pete Grey" > wrote in message
...
> I ride Gatorskins in the winter, 700x25's around the same pressure, maybe
> more like 115.
> I get similar mileage from them, and I weigh in about 165lb.
>
> My Conti GP 3000's only last about 1000mi in the summer months on my
faster
> bike.
>
> I consider both of these reasonable, for the good ride and handling from
the
> Conti's.
> I have had one (1) sidewall problem in using them for nearly 14 years now,
> YMMV. I also consider that reasonable, I think Conti has gotten a bad rap
> from a few of these cases being made public, I'd guess that other
> manufacturers have had the same problem from time-to-time.
>
> I've tried other longer-wearing tires a few times over the years, and I'm
> not switching:-]
>
> -pete
>
> "cheg" > wrote in message
> news:aG6Ac.103502$3x.15777@attbi_s54...
> >
> > "Dave" > wrote in message
> > ...
> > > Depends on the tire characteristics, your riding style, road surface
> > > material and climate, just like car tires. Grippier tires will wear
> earlier
> > > because of the softer compound. Hot climate will certainly wear tires
> > > faster; if you do a lot of hard pedaling or fast club rides, chances
are
> > > you're putting more road friction on the tires, and for example, here
in
> S
> > > Florida, many of the road surfaces we ride on have hard coral mixed
into
> the
> > > asphalt, so it can be harder on tires too. You need to look at what
> you're
> > > doing to your tires.
> > >
> > > BTW, 1400 miles is not bad wear for a set of tires, again depending on
> the
> > > conditions. If you had said 400 miles, I'd have really wondered. I
> like
> > > 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.
> > >
> > > Hope this helped....
> > >
> >
> > This is in Seattle, certainly not a hot climate by your standards. We
have
> hills
> > instead :-)
> >
> > The compound of the Ultra Gatorskins does seem softer than other tires
> I've
> > used. I don't ride particularly fast, though. I average about 200 miles
a
> week,
> > mostly commuting in the 15-17 mph range.
> >
> >
>
>

[cheg]

"Booker C. Bense"
tanford.edu> wrote in message
news:cav4s5
>
> cheg > wrote:
> >
> >
> >Why does higher pressure increase wear rate?
>
> _ Less of the tire contacts the road.
>
> > As far as the ride, the smoothness
> >of the ride is the one notable thing about Gatorskins that makes me want to
> >continue using them so I don't find them harsh at all.
>
> _ I think there is a typo in your message since I can't find any
> evidence that gatorskins come in 32mm width. For a 23mm width
> tire and your weight, 110 is probably about right...
>

27" x 1-1/4" => 32-630 ISO

> According to Jobst
> >Brandt's measured data higher pressure = lower rolling resistance, which
could
> >be considered a positive benefit. I don't know how significant the gain is
> >compared to aerodynamic drag and other mechanical losses, though.
>
> _ My own philosophy is to keep the tire pressure as low as is
> safe and avoids pinch flats. For me road comfort in a 3 or 4 hour
> ride is much more important than speed.
>
> _ Booker C. Bense

One man's comfort is another man's PITA.

[[email protected]]

On Fri, 18 Jun 2004 22:58:22 GMT,
wrote:

>Carl Fogel writes:
>
>>>> It's too bad as the Open Corsas have typically been the nicest
>>>> handling tires I've used, but they go away so quickly and they're
>>>> so expensive that I'm looking for something else.
>
>>> How do you [know] whether one tire handles better than another
>>> since traction is either there or not on pavement. There is no
>>> tire squeal or side-slip, although writers to this newsgroup
>>> sometimes describe their cornering as drifting in curves. This
>>> does not occur. Besides that, chip seal, the most abrasive, roads
>>> have poorer traction than concrete or hot-mix asphalt roads.
>
>> Maybe Tom notices that the traction is "not there" on the
>> pavement more often with poorer handling tires?
>
>Maybe shmaybe, let the man speak for himself. You don't have to hold
>his hand.
>
>> It seems unlikely, but are you saying that no rider can tell whether
>> one tire handles better than another in terms of traction?
>
>Unless it is a knobby tire (not a road tire of the kind in question)
>there is no perceptible difference in handling until is washes out in
>a curve, something that occurs with colored tires on wet roads. It is
>not something you prefer to test but it has been done both in situ and
>on the tire testing machine I once designed for Avocet to measure
>maximum lean angle for tires.
>
>> Since you offer no answer, your hastily typed question "How
>> do you [?] whether one tire handles better than another . .
>> ." seems rhetorical.
>
>That may be so in your estimation but I didn't ask you.
>
>> So how do you tell if one tire handles better than another?
>
>You test it on a machine. I originally performed such tests on a 16ft
>long paved plywood tiltbed increasing the angle until the bicycle
>slid. This was done at low speed and with protective clothing. There
>was a difference among tires tested. That was a few years ago.
>
>Jobst Brandt


Dear Jobst,

If you don't like people replying to your posts, a newsgroup
may not be the best place to spend your time.

So your position is that no rider can tell the difference
between the way different tires handle during normal riding
and that they can be distinguished only at low speed on a
machine.

Thanks,

Carl Fogel

[cheg]

> >> So how do you tell if one tire handles better than another?
> >
> >You test it on a machine. I originally performed such tests on a 16ft
> >long paved plywood tiltbed increasing the angle until the bicycle
> >slid. This was done at low speed and with protective clothing. There
> >was a difference among tires tested. That was a few years ago.
> >
> >Jobst Brandt
>
>
> Dear Jobst,
>
> If you don't like people replying to your posts, a newsgroup
> may not be the best place to spend your time.
>
> So your position is that no rider can tell the difference
> between the way different tires handle during normal riding
> and that they can be distinguished only at low speed on a
> machine.
>
> Thanks,
>
> Carl Fogel

Perhaps you should both start by defining "handle" in this context. If it is
strictly lateral load bearing capacity while rolling, then direct measurement
would be the way to go. If it includes other characteristics, eg. vibration
transmssion, then the measurement is not sufficient by itself.

[[email protected]]

On Sat, 19 Jun 2004 00:33:21 GMT, "cheg"
> wrote:

>
>> >> So how do you tell if one tire handles better than another?
>> >
>> >You test it on a machine. I originally performed such tests on a 16ft
>> >long paved plywood tiltbed increasing the angle until the bicycle
>> >slid. This was done at low speed and with protective clothing. There
>> >was a difference among tires tested. That was a few years ago.
>> >
>> >Jobst Brandt
>>
>>
>> Dear Jobst,
>>
>> If you don't like people replying to your posts, a newsgroup
>> may not be the best place to spend your time.
>>
>> So your position is that no rider can tell the difference
>> between the way different tires handle during normal riding
>> and that they can be distinguished only at low speed on a
>> machine.
>>
>> Thanks,
>>
>> Carl Fogel
>
>Perhaps you should both start by defining "handle" in this context. If it is
>strictly lateral load bearing capacity while rolling, then direct measurement
>would be the way to go. If it includes other characteristics, eg. vibration
>transmssion, then the measurement is not sufficient by itself.
>

Dear Cheg,

Yes, handling is probably many faceted.

A tire that stops well in a straight line on dry pavement,
for example, might not corner as well due to profile or
carcass design. Inflation alone varies so much in bicycle
tires that it may obscure all sorts of differences.

From what I see of Consumer Reports testing of car tires,
handling often varies between brands according to wet or dry
and between braking and cornering. They also do their best
to poll testers about less easily quantified characteristics
as "harshness," which I expect is what you have in mind with
vibration.

Unfortunately, tire handling for bicycles and motorcycles is
hard to test, since what would be a mere skid for a car is
likely to be a crash on two wheels and better riders may be
able to do more with the same equipment. That is,
practically anyone can crank a car on a skid pad up to a
certain speed and see whether it can stay on the curving
line, but riders on only two wheels need considerably more
confidence and skill to do the same thing at normal speeds
and higher.

I'm curious about bicycle tires and handling for two
reasons.

First, I know very little about it--my daily ride involves
neither high-speed cornering nor exciting stops.

Second, I have a vague suspicion that handling is relatively
unimportant in typical road competition. I sometimes wonder
whether bulldozer races place equal emphasis on cornering.

The Tour de France, for example, consists of rigid-frame
vehicles riding mostly in cooperative packs on pavement at
25-30 mph and sometimes up mountains alone at much lower
speeds. After three weeks, only a few minutes separate first
and second place. I doubt that anyone is going to whip Lance
Armstrong by mounting better-handling tires, but I'm willing
to learn otherwise.

Carl Fogel

[[email protected]]

Carl Fogel writes:

> If you don't like people replying to your posts, a newsgroup may not
> be the best place to spend your time.

Your interpretation of discourse here is trying hard to
mis-characterize what is said.

> So your position is that no rider can tell the difference between
> the way different tires handle during normal riding and that they
> can be distinguished only at low speed on a machine.

That is not what I said. You can test the wipe-out angle of tires at
speed but that is both painful and destructive to the bicyclist. An
alternative is to use a test bed and since speed is not a ruling
parameter, it can and has been be done at low speeds. I have done
that.

The point I tried to bring across is that road tires don't squeal or
slid on pavement until they have a sudden and unrecoverable breakout.
Therefore the question remains, how dose one arrive at the assessment
that a tire handles well.

I think that is a valid and simple question and it was not aimed at
you although if you have the answer I would like to hear it.

Jobst Brandt

[[email protected]]

Cheg Nospam writes:

>>>> So how do you tell if one tire handles better than another?

>>> You test it on a machine. I originally performed such tests on a
>>> 16ft long paved plywood tiltbed increasing the angle until the
>>> bicycle slid. This was done at low speed and with protective
>>> clothing. There was a difference among tires tested. That was a
>>> few years ago.

>> If you don't like people replying to your posts, a newsgroup may
>> not be the best place to spend your time.

>> So your position is that no rider can tell the difference between
>> the way different tires handle during normal riding and that they
>> can be distinguished only at low speed on a machine.

> Perhaps you should both start by defining "handle" in this
> context. If it is strictly lateral load bearing capacity while
> rolling, then direct measurement would be the way to go. If it
> includes other characteristics, eg. vibration transmssion, then the
> measurement is not sufficient by itself.

The term "handling" is adequately defined by use in the tire business
and it concerns itself with maneuverability in cornering and for cars
how well the tire tracks straight ahead. Ride comfort is another matter.


Jobst Brandt

[[email protected]]

On Sat, 19 Jun 2004 02:40:43 GMT,
wrote:

>Carl Fogel writes:
>
>> If you don't like people replying to your posts, a newsgroup may not
>> be the best place to spend your time.
>
>Your interpretation of discourse here is trying hard to
>mis-characterize what is said.
>
>> So your position is that no rider can tell the difference between
>> the way different tires handle during normal riding and that they
>> can be distinguished only at low speed on a machine.
>
>That is not what I said. You can test the wipe-out angle of tires at
>speed but that is both painful and destructive to the bicyclist. An
>alternative is to use a test bed and since speed is not a ruling
>parameter, it can and has been be done at low speeds. I have done
>that.
>
>The point I tried to bring across is that road tires don't squeal or
>slid on pavement until they have a sudden and unrecoverable breakout.
>Therefore the question remains, how dose one arrive at the assessment
>that a tire handles well.
>
>I think that is a valid and simple question and it was not aimed at
>you although if you have the answer I would like to hear it.
>
>Jobst Brandt


Dear Jobst,

So your position is that no rider can tell the difference
between the way different tires handle during normal riding
and that they an be distinguished--

--without pain and destruction--

--only at low speed on a test bed.

I think that is a valid and simple statement of what you
were actually saying to the original poster. I'm not arguing
with you, just trying to see what your position is.

Thanks,

Carl Fogel

[cheg]

> wrote in message
...
> Cheg Nospam writes:
>
>
> The term "handling" is adequately defined by use in the tire business
> and it concerns itself with maneuverability in cornering and for cars
> how well the tire tracks straight ahead. Ride comfort is another matter.
>
>

Seems like it would be more clear to call it "cornering traction" or something
like that for tires. Handling applied to vehicles is much more complex,
dependent on weight distribution, stiffness, steering geometry, drag, etc., as
well as traction. Can't do much about traditional usage, I guess.

[[email protected]]

Cheg Nospam writes:

>> The term "handling" is adequately defined by use in the tire
>> business and it concerns itself with maneuverability in cornering
>> and for cars how well the tire tracks straight ahead. Ride comfort
>> is another matter.

> Seems like it would be more clear to call it "cornering traction" or
> something like that for tires. Handling applied to vehicles is much
> more complex, dependent on weight distribution, stiffness, steering
> geometry, drag, etc., as well as traction. Can't do much about
> traditional usage, I guess.

TIRES! Not vehicles. This is about tires and that is extra simple
for road bicycle tires. Hnadling being how well the tire performs in
curves, nothing more.

Jobst Brandt

[Rick Onanian]

On Fri, 18 Jun 2004 22:31:38 GMT,
wrote:
>How do you whether one tire handles better than another since traction
>is either there or not on pavement. There is no tire squeal or
>side-slip although writers to this newsgroup sometimes describe their
>cornering as drifting in curves. This does not occur. Besides that,
>chip seal, the most abrasive, roads have poorer traction than concrete
>or hot-mix asphalt roads.

This may be all true in a perfect world where roads are fresh, clean
pavement. I, however, experienced a controllable side-slip on my
rear tire, followed by whole-bike drift, while doing some 35 mph
downhill, around a curve, on an older road whose pavement is
probably imperfect (probably not as flat a surface as a taut string,
for example), and it was probably not perfectly clean.

I was kinda zoned out, pedalling with all my might, when I felt it,
and before I processed that information, I found I was on the wrong
side of the road; slowing down brought back the missing traction. No
accident resulted, but I did get quite scared.

It was very exciting, and if I thought I could purposely duplicate
it without an accident, I'd love to.

In a later message, Jobst wrote:
>You test it on a machine. I originally performed such tests on a 16ft
>long paved plywood tiltbed increasing the angle until the bicycle
>slid.

I suspect that the different compounds, as well as tire casing
constructions, react differently to the changing conditions of a
road while moving than to the static conditions of a stopped bicycle
on a tilted platform. Per my example above, where I theorize that
the pavement is probably slightly wavy (although I've never noticed
it, a tire on a 35 mph bike would), the tire's casing would have
quite an effect on how the tire's tread stays in contact with the
road.

The casing also must compensate for imbalanced wheels. We don't
balance our wheels because it doesn't bother us; but if you lift
your bike, hold it in your hand, and pedal the rear wheel up to 25
mph, you may feel the bike jumping up and down. Mine does; I taped
weights to the wheel until it was balanced, just to see if I could.
I suppose it could be something odd with the bearings...

Additionally, that test is certainly irrelevant for lateral
traction; it only tests fore-aft traction. Sideways, the tire bends
(again, involving the casing), and also the rider leans, exposing a
different part of the tire to the road.

Later still, Jobst wrote:
>TIRES! Not vehicles. This is about tires and that is extra simple
>for road bicycle tires. Hnadling being how well the tire performs in
>curves, nothing more.

Then what makes you think your tilt-brake-slide test is relevant to
this thread?

Then, Carl did his best to determine what Jobst is trying to say:
> So your position is that no rider can tell the difference
>between the way different tires handle during normal riding
>and that they an be distinguished--
>--without pain and destruction--
>--only at low speed on a test bed.

If, in fact, that is a correct translation, then I disagree that a
rider can't tell; and more importantly, if I'm wrong and the only
way to know how a tire handles is to wipe out, then it would seem
_very_ important to know how the tire handles before buying it; at
that point, one's life could depend on a tire's handling ability.
--
Rick Onanian

[[email protected]]

Rick Onanian writes:

>> How do you whether one tire handles better than another since
>> traction is either there or not on pavement. There is no tire
>> squeal or side-slip although writers to this newsgroup sometimes
>> describe their cornering as drifting in curves. This does not
>> occur. Besides that, chip seal, the most abrasive, roads have
>> poorer traction than concrete or hot-mix asphalt roads.

> This may be all true in a perfect world where roads are fresh, clean
> pavement. I, however, experienced a controllable side-slip on my
> rear tire, followed by whole-bike drift, while doing some 35 mph
> downhill, around a curve, on an older road whose pavement is
> probably imperfect (probably not as flat a surface as a taut string,
> for example), and it was probably not perfectly clean.

If it was pavement with no sand or other solid (lubricant) I am
reasonably sure that you did not drift around a curve on pavement.
None of the best bicycle riders in this area believe that this is
possible either nor does the tire testing machine that displays sudden
and irrecoverable break out while determining maximum lean angle.

> I was kinda zoned out, pedalling with all my might, when I felt it,
> and before I processed that information, I found I was on the wrong
> side of the road; slowing down brought back the missing traction. No
> accident resulted, but I did get quite scared.

I am sure you experienced loss of traction but it was not on clean dry
pavement, that condition where cornering ability of a tire can only be
assessed by measurement at the moment of break out and crashing. That
is not a reasonable thing to attempt and that is why I asked how
handling of one tire over another under similar conditions is
assessed.

> It was very exciting, and if I thought I could purposely duplicate
> it without an accident, I'd love to.

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.

> In a later message, Jobst wrote:

>> You test it on a machine. I originally performed such tests on a
>> 16ft long paved plywood tiltbed increasing the angle until the
>> bicycle slid.

> I suspect that the different compounds, as well as tire casing
> constructions, react differently to the changing conditions of a
> road while moving than to the static conditions of a stopped bicycle
> on a tilted platform. Per my example above, where I theorize that
> the pavement is probably slightly wavy (although I've never noticed
> it, a tire on a 35 mph bike would), the tire's casing would have
> quite an effect on how the tire's tread stays in contact with the
> road.

Who's talking about static condition? The test bed was ridden across
at about 15mph. That is dynamic enough to give a reading and to
differentiate between slick tires of that time and ones with a raised
center ridge. Bicycle tires do not generate enough heat to have any
effect on traction. If they did, you would be able to feel it after
making a hard stop from, say, 30mph on a flat road. That is more work
than a tire does when cornering because all the weight is on the front
wheel and the retardation is close to that of hard cornering.

> The casing also must compensate for imbalanced wheels. We don't
> balance our wheels because it doesn't bother us; but if you lift
> your bike, hold it in your hand, and pedal the rear wheel up to 25
> mph, you may feel the bike jumping up and down. Mine does; I taped
> weights to the wheel until it was balanced, just to see if I could.
> I suppose it could be something odd with the bearings...

I guess you missed the balance experiments that were done by placing
lead weights at one spoke location and other such balance and
imbalance conditions that are used as excuses for all sorts of rider
errors. This has all been done. None of the best descenders I have
talked to has ever considered balanced tires as a benefit.

> Additionally, that test is certainly irrelevant for lateral
> traction; it only tests fore-aft traction. Sideways, the tire bends
> (again, involving the casing), and also the rider leans, exposing a
> different part of the tire to the road.

I think you are not visualizing what occurs when a bicycle leans in a
curve. The tire testing machine leaned the tire that was loaded
in-plane onto a large paved drum while a set of sensors triggered the
recording of the angle at which the wheel slipped out. This was
repeatable and was done at about 20mph. There are no side loads any
more than there are side loads on a bicycle when cornering.

> Later still, Jobst wrote:

>> TIRES! Not vehicles. This is about tires and that is extra simple
>> for road bicycle tires. Handling being how well the tire performs
>> in curves, nothing more.

> Then what makes you think your tilt-brake-slide test is relevant to
> this thread?

The test was cornering and that alone and was repeatable. Even though
the in situ test at 40mph was made, the limit was not exceeded:

http://tinyurl.com/2gbsj

> Then, Carl did his best to determine what Jobst is trying to say:
>> So your position is that no rider can tell the difference
>> between the way different tires handle during normal riding
>> and that they an be distinguished--
>> --without pain and destruction--
>> --only at low speed on a test bed.

> If, in fact, that is a correct translation, then I disagree

I disagree also because that is not a correct translation. In a
subsequent reply I reiterated what I said and meant. Maybe you can
take that up and tell me how you assess the handling differences
between similar sized tires of different manufacture under similar
conditions. By this I do not mean a singular anecdote in which a
certain tire did thus and so with no comparison.

> I disagree that a rider can't tell; and more importantly, if I'm
> wrong and the only way to know how a tire handles is to wipe out,
> then it would seem _very_ important to know how the tire handles
> before buying it; at that point, one's life could depend on a tire's
> handling ability.

Could you explain what this paragraph means with respect to a rider
being able to feel that one tire handles better than another? My
statement is that since road tires (without knobs) do not have a
transition point on smooth dry pavement, riders who claim that a tire
handles well are merely repeating advertising copy, because below the
slip out limit (the only difference) no difference in handling is
noticeable. Again, handling being control in curves.

Jobst Brandt

[Rick Onanian]

On Sun, 20 Jun 2004 00:43:09 GMT,
wrote:
>Rick Onanian writes:
>> This may be all true in a perfect world where roads are fresh, clean
>> pavement. I, however, experienced a controllable side-slip on my
>> rear tire, followed by whole-bike drift, while doing some 35 mph
>> downhill, around a curve, on an older road whose pavement is
>> probably imperfect (probably not as flat a surface as a taut string,
>> for example), and it was probably not perfectly clean.
>
>If it was pavement with no sand or other solid (lubricant) I am
>reasonably sure that you did not drift around a curve on pavement.

It probably was not perfect, fresh, clean, 100% black, unmolested
pavement. I'm sure that it includes some dust and dirt. Many
driveways on that street are dirt. No dirt was visible on the
pavement, but it wasn't the 100% dark jet black of brand new
pavement either.

In short, it's a real world condition.

>I am sure you experienced loss of traction but it was not on clean dry
>pavement, that condition where cornering ability of a tire can only be
>assessed by measurement at the moment of break out and crashing. That

Agreed. It was a real road, the kind where bicyclists depend on tire
traction.

>is not a reasonable thing to attempt and that is why I asked how
>handling of one tire over another under similar conditions is
>assessed.

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.

>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.

>>> You test it on a machine. I originally performed such tests on a
>>> 16ft long paved plywood tiltbed increasing the angle until the
>>> bicycle slid.
>
>> I suspect that the different compounds, as well as tire casing
>> constructions, react differently to the changing conditions of a
>> road while moving than to the static conditions of a stopped bicycle
>> on a tilted platform. Per my example above, where I theorize that
>> the pavement is probably slightly wavy (although I've never noticed
>> it, a tire on a 35 mph bike would), the tire's casing would have
>> quite an effect on how the tire's tread stays in contact with the
>> road.
>
>Who's talking about static condition? The test bed was ridden across
>at about 15mph. That is dynamic enough to give a reading and to

I think I understand; the bed was tilted sideways while you rode
across it, leaning to the high side of the bed to keep yourself
plumb. That makes more sense; I visualized you on the non-moving
bike holding the brakes as the front of the bed raised (in a dumping
motion), until the bike slid.

>> The casing also must compensate for imbalanced wheels. We don't
>> balance our wheels because it doesn't bother us; but if you lift
>> your bike, hold it in your hand, and pedal the rear wheel up to 25
>> mph, you may feel the bike jumping up and down. Mine does; I taped
>> weights to the wheel until it was balanced, just to see if I could.
>> I suppose it could be something odd with the bearings...
>
>I guess you missed the balance experiments that were done by placing
>lead weights at one spoke location and other such balance and
>imbalance conditions that are used as excuses for all sorts of rider
>errors. This has all been done. None of the best descenders I have
>talked to has ever considered balanced tires as a benefit.

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.

>> Additionally, that test is certainly irrelevant for lateral
>> traction; it only tests fore-aft traction. Sideways, the tire bends
>> (again, involving the casing), and also the rider leans, exposing a
>> different part of the tire to the road.
>
>I think you are not visualizing what occurs when a bicycle leans in a
>curve. The tire testing machine leaned the tire that was loaded
>in-plane onto a large paved drum while a set of sensors triggered the
>recording of the angle at which the wheel slipped out. This was
>repeatable and was done at about 20mph. There are no side loads any
>more than there are side loads on a bicycle when cornering.

A different portion of the tread, supported differently by the
sidewalls, is in contact with the road. However, the tire testing
machine of which you speak, and of which I was unaware in my
previous message, would test that.

>> I disagree that a rider can't tell; and more importantly, if I'm
>> wrong and the only way to know how a tire handles is to wipe out,
>> then it would seem _very_ important to know how the tire handles
>> before buying it; at that point, one's life could depend on a tire's
>> handling ability.
>
>Could you explain what this paragraph means with respect to a rider
>being able to feel that one tire handles better than another? My

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

More importantly, however, you've failed to address the big issue --
if tires really do break out without any warning as you say, then it
would seem extremely important to be able to choose a tire based on
it's actual tested and reviewed handling. A high speed traction
failure accident sure sounds dangerous! I doubt I would have ridden
home if my slip incident turned into a complete loss of control; at
35 mph or so, I would have wrapped my body around a tree or a stone
wall (the two types of object found on the side of that road).
--
Rick Onanian

[[email protected]]

Rick Onanian writes:

>>> This may be all true in a perfect world where roads are fresh, clean
>>> pavement. I, however, experienced a controllable side-slip on my
>>> rear tire, followed by whole-bike drift, while doing some 35 mph
>>> downhill, around a curve, on an older road whose pavement is
>>> probably imperfect (probably not as flat a surface as a taut string,
>>> for example), and it was probably not perfectly clean.

>> If it was pavement with no sand or other solid (lubricant) I am
>> reasonably sure that you did not drift around a curve on pavement.

> It probably was not perfect, fresh, clean, 100% black, unmolested
> pavement. I'm sure that it includes some dust and dirt. Many
> driveways on that street are dirt. No dirt was visible on the
> pavement, but it wasn't the 100% dark jet black of brand new
> pavement either.

I'm not quibbling about common dust on roads. The dry pavement you
describe fits the definition of clean dry pavement and on such a
surface, no "drifting" or sliding is possible without crashing. This
has been measured often enough and we have not seen anyone who can
demonstrate a slide in a curve since the lean angle for that is
greater than 45 degrees to the pavement. At that angle, no one I or
any of the fastest descenders that I know have seen anyone do that and
not crash.

> In short, it's a real world condition.

It doesn't take that much definition.

>> I am sure you experienced loss of traction but it was not on clean
>> dry pavement, that condition where cornering ability of a tire can
>> only be assessed by measurement at the moment of break out and
>> crashing.

> Agreed. It was a real road, the kind where bicyclists depend on tire
> traction.

>> That is not a reasonable thing to attempt and that is why I asked
>> how handling of one tire over another under similar conditions is
>> assessed.

> 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. We have a
few riders in this area who corner at the limit of near 45 degrees and
the testing machine predicts break out at 47 or so with slick tread
repeatably.

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

>>>> You test it on a machine. I originally performed such tests on a
>>>> 16ft long paved plywood tiltbed increasing the angle until the
>>>> bicycle slid.

>>> I suspect that the different compounds, as well as tire casing
>>> constructions, react differently to the changing conditions of a
>>> road while moving than to the static conditions of a stopped
>>> bicycle on a tilted platform. Per my example above, where I
>>> theorize that the pavement is probably slightly wavy (although
>>> I've never noticed it, a tire on a 35 mph bike would), the tire's
>>> casing would have quite an effect on how the tire's tread stays in
>>> contact with the road.

>> Who's talking about static condition? The test bed was ridden across
>> at about 15mph. That is dynamic enough to give a reading and to

> I think I understand; the bed was tilted sideways while you rode
> across it, leaning to the high side of the bed to keep yourself
> plumb. That makes more sense; I visualized you on the non-moving
> bike holding the brakes as the front of the bed raised (in a dumping
> motion), until the bike slid.

I didn't lean, I rode across it upright. The test bed was tilted.
When the tilt was too steep, the bicycle slid out unrecoverably as it
does on a road.

>>> The casing also must compensate for imbalanced wheels. We don't
>>> balance our wheels because it doesn't bother us; but if you lift
>>> your bike, hold it in your hand, and pedal the rear wheel up to 25
>>> mph, you may feel the bike jumping up and down. Mine does; I
>>> taped weights to the wheel until it was balanced, just to see if I
>>> could. I suppose it could be something odd with the bearings...

>> I guess you missed the balance experiments that were done by
>> placing lead weights at one spoke location and other such balance
>> and imbalance conditions that are used as excuses for all sorts of
>> rider errors. This has all been done. None of the best descenders
>> I have talked to has ever considered balanced tires as a benefit.

> 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. 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
said, I have done balance and imbalance tests with no perceptible
effect and reported the results here. These tests were done to prove
that shimmy is not related to wheel im/balance.

>>> Additionally, that test is certainly irrelevant for lateral
>>> traction; it only tests fore-aft traction. Sideways, the tire
>>> bends (again, involving the casing), and also the rider leans,
>>> exposing a different part of the tire to the road.

>> I think you are not visualizing what occurs when a bicycle leans in
>> a curve. The tire testing machine leaned the tire that was loaded
>> in-plane onto a large paved drum while a set of sensors triggered
>> the recording of the angle at which the wheel slipped out. This
>> was repeatable and was done at about 20mph. There are no side
>> loads any more than there are side loads on a bicycle when
>> cornering.

> A different portion of the tread, supported differently by the
> sidewalls, is in contact with the road. However, the tire testing
> machine of which you speak, and of which I was unaware in my
> previous message, would test that.

I don't understand what you propose here. The tires tested were
typical of available major brand tires.

>>> I disagree that a rider can't tell; and more importantly, if I'm
>>> wrong and the only way to know how a tire handles is to wipe out,
>>> then it would seem _very_ important to know how the tire handles
>>> before buying it; at that point, one's life could depend on a
>>> tire's handling ability.

>> Could you explain what this paragraph means with respect to a rider
>> being able to feel that one tire handles better than another?

> 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.

> More importantly, however, you've failed to address the big issue --
> if tires really do break out without any warning as you say, then it
> would seem extremely important to be able to choose a tire based on
> it's actual tested and reviewed handling. A high speed traction
> failure accident sure sounds dangerous! I doubt I would have ridden
> home if my slip incident turned into a complete loss of control; at
> 35 mph or so, I would have wrapped my body around a tree or a stone
> wall (the two types of object found on the side of that road). --

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.

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.

Jobst Brandt

[Rick Onanian]

On Tue, 22 Jun 2004 01:33:44 GMT,
wrote:
>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. We have a

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 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.

>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.

>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.

>> 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?

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.

> 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 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.
--
Rick Onanian

[[email protected]]

On Tue, 22 Jun 2004 01:33:44 GMT,
wrote:

[snip]

>
>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.
>
>Jobst Brandt


Dear Jobst,

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?

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

Carl Fogel

[Benjamin Lewis]

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

[[email protected]]

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

[[email protected]]

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

[[email protected]]

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

[Benjamin Lewis]

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

[Helmut Springer]

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

[Hjalmar Duklæt]

> 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

[[email protected]]

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

[Tim McNamara]

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.

[Tom Nakashima]

> 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

[Rick Onanian]

On Tue, 22 Jun 2004 19:25:32 GMT,
wrote:
>> 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.

What do you find unrealistic about it? Are you not strong enough to
hold the rear of your bike up with one hand, and pedal it in a high
gear with the other?

That is a REAL, not just realistic, demonstration of a force found
in a moving bicycle. It is a force that we choose to ignore, because
it seems inconsequential; but if we're talking about high-precision
rating of tire handling ability, it could make a difference, just as
a bumpy road makes a difference in traction. The casing of the tire
would affect how well it deals with the constant high frequency
load-unload cycle.
--
Rick Onanian

[Tom Sherman]

Helmut Springer wrote:

> 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-/

This is true of human life in general: talking the talk almost
invariably is more rewarding than walking the walk.

--
Tom Sherman – Quad City Area

[[email protected]]

Tom Nakashima writes:

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

> I have yet to see a cyclist crash or go down on DRY payment when
> leaning too far into a turn.

I have and did so myself in years past. That's called low-siding when
the bicycle goes out from under the rider. Low side because the
distance to the ground is relatively small. High-siding is worse
because the rider goes up and over the bicycle and hits harder. My
friend did that on Mt. Hamilton recently on the day of the bicycle
race... Collar bone + two ribs.

> I have a crash on wet payment as in the case of Jan Ulrich in last
> year's Tour de France.

I've done that too, also low-side but broke a hip on one of these.
That was all years ago when I was "young and beautiful" as ladies
often say.

> Is there a warning when you lean too far over in a turn that would
> be unrecoverable and result in a crash.

None at all, and when it starts going it is obvious. Judging from
riders I pass down hills, few people ever get close to that point on
dry pavement. On wet roads it occurs more often because the limit is
so variable and is hard to assess.

> Is it possible to recover if you have leaned too far over in a turn?

Not on dry pavement because there is nothing approaching that will
increase traction at that lean angle... that is increasing rapidly as
the slide progresses.

> 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.

I don't do such tests at speed. I ride below the limit, that is more
than most riders are willing to approach because they haven't
experienced the angle that is possible. It is also good to have seen
tires on a testing machine exceed 45 degrees to have a feel for what
is reasonable.

Jobst Brandt

[Tim McNamara]

"Tom Nakashima" > writes:

> > 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've seen it in crits. Is there a warning? No- it's pretty much
instantaneous. Is it recoverable? Only by sheer luck. My personal
experience was with being leaned way over in a crit and then striking
a pedal, which lifted the rear tire. I didn't crash, but that had
everything to do with luck and nothing to do with riding skills.
Scared the hell out of the guy on my wheel.

[Tim McNamara]

Rick Onanian > writes:

> On Tue, 22 Jun 2004 19:25:32 GMT,
> wrote:
>>> 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.
>
> What do you find unrealistic about it? Are you not strong enough to
> hold the rear of your bike up with one hand, and pedal it in a high
> gear with the other?
>
> That is a REAL, not just realistic, demonstration of a force found
> in a moving bicycle. It is a force that we choose to ignore, because
> it seems inconsequential; but if we're talking about high-precision
> rating of tire handling ability, it could make a difference, just as
> a bumpy road makes a difference in traction. The casing of the tire
> would affect how well it deals with the constant high frequency
> load-unload cycle.

It seems inconsequential precisely because it is. Have you calculated
the forces involved in this imbalance relative to the vertical loading
from your body weight? It'd be an interesting mathematical problem-
with the force resulting from the imbalance being a tiny fraction of
the mass of the rider and bike.

This notion of imbalance as a "significant" issue comes from cars,
where the wheel is free to have a vertical excursion thanks to the
suspension and then only if the shock absorber is worn to the point
that it doesn't damp the wheel movement correctly. A bicycle wheel
cannot move freely in this manner even in a fully suspended bike,
because the forces probably aren't high enough to overcome stiction.
The forces are much higher with a car wheel, which is turning several
times faster than a bicycle wheel and weighs 10 to 20 times more, so
there is much more inertial energy involved. When you hold the bike
up in the air and spin the wheel, you are providing no damping.

[Rick Onanian]

On Tue, 22 Jun 2004 23:42:56 -0500, Tim McNamara
> wrote:
>Rick Onanian > writes:
>> it seems inconsequential; but if we're talking about high-precision
>> rating of tire handling ability, it could make a difference, just as
>
>It seems inconsequential precisely because it is. Have you calculated
>the forces involved in this imbalance relative to the vertical loading
>from your body weight? It'd be an interesting mathematical problem-
>with the force resulting from the imbalance being a tiny fraction of
>the mass of the rider and bike.

I suspect the force in question is only a few pounds. It's
inconsequential for real-world riding, but not for
_high-precision_measurements_. We can either talk about real-world
handling, on roads whose imperceptibly imperfect surface probably
provides more reciprocating force than wheel imbalance...or we can
talk about measuring tire ability very precisely. Or we can quit
because, well, this discussion is pointless... <G>
--
Rick Onanian

[[email protected]]

Tim McNamara writes:

>>> 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've seen it in crits. Is there a warning? No- it's pretty much
> instantaneous. Is it recoverable? Only by sheer luck. My personal
> experience was with being leaned way over in a crit and then
> striking a pedal, which lifted the rear tire. I didn't crash, but
> that had everything to do with luck and nothing to do with riding
> skills. Scared the hell out of the guy on my wheel.

Ah yes, but that does not rate as a break out from leaning too far.
That fits the description of a temporary loss of traction below the
limit. It is similar to slipping across a slick spot or a spot of
sand on the road. Once the lean angle exceeds the traction there is
no return to stability.

Jobst Brandt

[Benjamin Weiner]

wrote:
> Tom Nakashima writes:

> > I have yet to see a cyclist crash or go down on DRY payment when
> > leaning too far into a turn.

> I have and did so myself in years past. That's called low-siding when
> the bicycle goes out from under the rider. Low side because the
> distance to the ground is relatively small. High-siding is worse
> because the rider goes up and over the bicycle and hits harder. My
> friend did that on Mt. Hamilton recently on the day of the bicycle
> race... Collar bone + two ribs.

> > Is there a warning when you lean too far over in a turn that would
> > be unrecoverable and result in a crash.

> None at all, and when it starts going it is obvious. Judging from
> riders I pass down hills, few people ever get close to that point on
> dry pavement. On wet roads it occurs more often because the limit is
> so variable and is hard to assess.

> > Is it possible to recover if you have leaned too far over in a turn?

> Not on dry pavement because there is nothing approaching that will
> increase traction at that lean angle... that is increasing rapidly as
> the slide progresses.

> > 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.

> I don't do such tests at speed. I ride below the limit, that is more
> than most riders are willing to approach because they haven't
> experienced the angle that is possible. It is also good to have seen
> tires on a testing machine exceed 45 degrees to have a feel for what
> is reasonable.

I think most riders are chary of approaching the limit of lean
angle, since it is difficult to judge when you are approaching
the limit and the penalty is obvious. As a corollary, when people
go into a turn too hot, I think they usually instinctively take it
too wide and cross the centerline or go off the road, rather than
increase lean and low-side it. Ullrich went into the bushes that way
in the Tour a few years ago. That may be why one rarely sees
people low-siding on dry pavement.

A couple of my friends say they can take that first left hand
turn on Pescadero Road without any braking, but I'm too chicken;
it is a long way to ride home with road rash.

[[email protected]]

Benjamin Weiner writes:

> I think most riders are wary of approaching the limit of lean
> angle, since it is difficult to judge when you are approaching the
> limit and the penalty is obvious. As a corollary, when people go
> into a turn too hot, I think they usually instinctively take it too
> wide and cross the centerline or go off the road, rather than
> increase lean and low-side it. Ullrich went into the bushes that
> way in the Tour a few years ago. That may be why one rarely sees
> people low-siding on dry pavement.

Some of that is because the idea that one should not brake in a turn
has been pounded into their heads. This is untrue as I have explained
and it is evident from anyone who is cornering near the limit. They
always are on the brakes in the apex of the turn. The details of
this are outlined in:

http://draco.acs.uci.edu/rbfaq/FAQ/9.15.html

and shown in:

http://tinyurl.com/2gbsj

> A couple of my friends say they can take that first left hand
> turn on Pescadero Road without any braking, but I'm too chicken;
> it is a long way to ride home with road rash.

That is the turn in the picture above and I do not take it without
braking. If they are doing that then they are not going fast enough
as they enter the curve. Of course that also depends on how
streamlined they are with respect to their weight. I suspect I could
take that corner without braking if I was wearing a floppy jacket and
didn't pedal on the approach to the curve.

The second left hand curve also requires braking if you are going
fast, even though it has a larger radius. At that point you should be
going faster than in the previous left hander.

Jobst Brandt

[Tim McNamara]

writes:

> Tim McNamara writes:
>
>>>> 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've seen it in crits. Is there a warning? No- it's pretty much
>> instantaneous. Is it recoverable? Only by sheer luck. My
>> personal experience was with being leaned way over in a crit and
>> then striking a pedal, which lifted the rear tire. I didn't crash,
>> but that had everything to do with luck and nothing to do with
>> riding skills. Scared the hell out of the guy on my wheel.
>
> Ah yes, but that does not rate as a break out from leaning too far.

Yes, that's true. I was a little OT there.

> That fits the description of a temporary loss of traction below the
> limit. It is similar to slipping across a slick spot or a spot of
> sand on the road. Once the lean angle exceeds the traction there is
> no return to stability.

I've had slight slippages like that occur in races crossing the lane
striping; slipping on these is much more pronounced when it is wet, of
course. But the width of the excursion, if that's the correct term,
is only a couple of inches and then once you're off the stripe you're
back on pavement with a high coefficient of friction. Front wheel
slippage seems to be less recoverable than rear wheel slippage.

If one wishes to see lots of crashes due to such slippage, watch the
1993 men's road race championships in Oslo Norway- a nasty wet day
with lots of crashes resulting from the wheels slipping out on lane
stripes. Some of them looked quite painful. IIRC Ekimov actually
went over a "Jersey wall" type barrier and landed on commuter railroad
tracks.

[[email protected]]

Tim McNamara writes:

>> That fits the description of a temporary loss of traction below the
>> limit. It is similar to slipping across a slick spot or a spot of
>> sand on the road. Once the lean angle exceeds the traction there
>> is no return to stability.

> I've had slight slippages like that occur in races crossing the lane
> striping; slipping on these is much more pronounced when it is wet,
> of course. But the width of the excursion, if that's the correct
> term, is only a couple of inches and then once you're off the stripe
> you're back on pavement with a high coefficient of friction. Front
> wheel slippage seems to be less recoverable than rear wheel
> slippage.

> If one wishes to see lots of crashes due to such slippage, watch the
> 1993 men's road race championships in Oslo Norway- a nasty wet day
> with lots of crashes resulting from the wheels slipping out on lane
> stripes. Some of them looked quite painful. IIRC Ekimov actually
> went over a "Jersey wall" type barrier and landed on commuter
> railroad tracks.

I am curious about the tires these riders used on that course. From
what I have seen, many racers ride on colored tires, some of which
make all sorts of claims to have more traction on the side than the
middle depending on color stripes. This is so much BS because a rider
needs maximum traction when braking before a curve while upright as
well as needing it to get around the corner. There is no excuse
except fashion to have any less traction than the best on the entire
tread and that is presently still gotten only with carbon black tread.

People who say otherwise are either lying or are as uneducated in the
matter as the public on whom they pass this sort of hype is. The
former is probably true, there not being an excess of tribological
expertise in the bicycle business, judging from the faux pas we see
regularly. I recall when Umma-Gumma, non black, tires were foisted on
the 7-Eleven team for their lower RR but were so bad in the wet that
crashes rapidly got them back to the supplier.

Jobst Brandt

[Dave Lehnen]

wrote:

>
> I am curious about the tires these riders used on that course. From
> what I have seen, many racers ride on colored tires, some of which
> make all sorts of claims to have more traction on the side than the
> middle depending on color stripes. This is so much BS because a rider
> needs maximum traction when braking before a curve while upright as
> well as needing it to get around the corner. There is no excuse
> except fashion to have any less traction than the best on the entire
> tread and that is presently still gotten only with carbon black tread.
>

Since maximum braking when upright is limited by the angle from the
front contact patch to the center of gravity, as often discussed on
this newsgroup, traction greater than required to raise the rear
wheel does not provide better deceleration. Even the hardest-
compound touring tires seem capable of lifting the rear wheel, at
least in dry conditions.

When cornering, acceleration is limited only by traction. It would
make sense to trade off some tread life, or rolling resistance, or
cut resistance, if it would help traction, on the side tread.

Since bicycles can't brake at much more than about 0.6g, it would
make sense to optimize the center tread for other desirable
properties, as long as traction was more than could be used anyway.

> People who say otherwise are either lying or are as uneducated in the
> matter as the public on whom they pass this sort of hype is. The
> former is probably true, there not being an excess of tribological
> expertise in the bicycle business, judging from the faux pas we see
> regularly. I recall when Umma-Gumma, non black, tires were foisted on
> the 7-Eleven team for their lower RR but were so bad in the wet that
> crashes rapidly got them back to the supplier.
>
> Jobst Brandt
>

Dave Lehnen

[Tim McNamara]

writes:

> Tim McNamara writes:
>
>> If one wishes to see lots of crashes due to such slippage, watch
>> the 1993 men's road race championships in Oslo Norway- a nasty wet
>> day with lots of crashes resulting from the wheels slipping out on
>> lane stripes. Some of them looked quite painful. IIRC Ekimov
>> actually went over a "Jersey wall" type barrier and landed on
>> commuter railroad tracks.
>
> I am curious about the tires these riders used on that course.

Boy, I have no idea and I don't have a copy of the video. I do
remember quite clearly seeing riders slip out in turns as they crossed
the heavy white painted stripes, the wheels going out almost
instantaneously. There were some very painful looking crashes.

[Tom Nakashima]

> wrote in message
...
>
> > I have yet to see a cyclist crash or go down on DRY payment when
> > leaning too far into a turn.
>
> I have and did so myself in years past. That's called low-siding when
> the bicycle goes out from under the rider. Low side because the
> distance to the ground is relatively small. High-siding is worse
> because the rider goes up and over the bicycle and hits harder. My
> friend did that on Mt. Hamilton recently on the day of the bicycle
> race... Collar bone + two ribs.
>
I didn't think "High-siding" was possible on a bicycle until I saw Joseba
Beloki do it in last years Tour de France. I believe that was due to melted
tar at high speeds through a turn. I'm thinking he might have hit the rear
brake.

I'm don't worry much about my cornering ability , but more concerned about
the road condition on high speed descents. My hardest fall was when someone
put sand on the road during the winter to help melt the ice. The roads were
dry, but I lost traction on the sand. I also slipped and almost lost it on
the back side of Mt. Hamilton due to some gravel on the road.
-tom

[S o r n i]

g.daniels wrote:

> what happened to walnut shells?

Like you, they're cracked.

Bill "ty...tyvm" S.

[Tom Sherman]

Tim McNamara wrote:

> ...
> If one wishes to see lots of crashes due to such slippage, watch the
> 1993 men's road race championships in Oslo Norway....

Sorry, my time machine is out of commission. ;)

--
Tom Sherman – Quad City Area

[[email protected]]

Dave Lehnen writes:

>> I am curious about the tires these riders used on that course.
>> From what I have seen, many racers ride on colored tires, some of
>> which make all sorts of claims to have more traction on the side
>> than the middle depending on color stripes. This is so much BS
>> because a rider needs maximum traction when braking before a curve
>> while upright as well as needing it to get around the corner.
>> There is no excuse except fashion to have any less traction than
>> the best on the entire tread and that is presently still gotten
>> only with carbon black tread.

> Since maximum braking when upright is limited by the angle from the
> front contact patch to the center of gravity, as often discussed on
> this newsgroup, traction greater than required to raise the rear
> wheel does not provide better deceleration. Even the hardest-
> compound touring tires seem capable of lifting the rear wheel, at
> least in dry conditions.

I think you'll find that braking in the wet can skid the front tire
before the rear wheel lifts but that is less than the whole story. In
poor traction, rear wheel braking is also needed and compromising that
which carbon black tires offer has caused crashes even while braking.

> When cornering, acceleration is limited only by traction. It would
> make sense to trade off some tread life, or rolling resistance, or
> cut resistance, if it would help traction, on the side tread.

That may be the thinking of those who have different center stripes
from edge tread but they are inconsistent, some having the color on
the sides and black in the center, others having the converse. I
suspect that both colored and black are silica filled instead of
carbon.

> Since bicycles can't brake at much more than about 0.6g, it would
> make sense to optimize the center tread for other desirable
> properties, as long as traction was more than could be used anyway.

Not on my bicycle. I have ridden enough wet mountain passes and
exceeded traction often enough to not mess with even poorer traction
that I had on carbon tires.

>> People who say otherwise are either lying or are as uneducated in
>> the matter as the public on whom they pass this sort of hype is.
>> The former is probably true, there not being an excess of
>> tribological expertise in the bicycle business, judging from the
>> faux pas we see regularly. I recall when Umma-Gumma, non black,
>> tires were foisted on the 7-Eleven team for their lower RR but were
>> so bad in the wet that crashes rapidly got them back to the
>> supplier.

Jobst Brandt

[[email protected]]

Tim McNamara writes:

>>> If one wishes to see lots of crashes due to such slippage, watch
>>> the 1993 men's road race championships in Oslo Norway- a nasty wet
>>> day with lots of crashes resulting from the wheels slipping out on
>>> lane stripes. Some of them looked quite painful. IIRC Ekimov
>>> actually went over a "Jersey wall" type barrier and landed on
>>> commuter railroad tracks.

>> I am curious about the tires these riders used on that course.

> Boy, I have no idea and I don't have a copy of the video. I do
> remember quite clearly seeing riders slip out in turns as they
> crossed the heavy white painted stripes, the wheels going out almost
> instantaneously. There were some very painful looking crashes.

Well for slick material, all bets are off. Metal utility covers,
solid paint stripes, and crack sealant are slick to any kind of
rubber. It's the rider's business to not demand any side forces from
such surfaces. Of course, in a dense pack of riders, that may not be
visible until it is too late.

I once watched a video of a Paris-Roubaix rider go down on a straight
section of basalt cobbles just from the inter cobble rounded seams. I
recall in the days of yore I would demonstrate this with my car at a
low rolling speed and run it up through the gears on wet basalt
without gaining more than 2-3mph while the tachometer registered
3000rpm in 3rd (of 4) gear. That makes a badly floating rear end if
you aren't on a level street.

Jobst Brandt