Schwalbe Technical Information

Tosspot said:

http://www.schwalbe.de/gbl/en/tech_info/

Stumbled across this again, so I post it for posterity. Quite useful I
feel.

on the subject of tire tread and slicks:

"Even in wet conditions, on a normal, smooth road, a slick tire actually
provides better grip than a tire with a tread, because the contact area
is larger.

The situation is much different on a rough road and even worse on a dirt
trail as in these cases the degree of control provided by a slick tire
is extremely limited.

A slightly serrated surface on the tire tread can have a positive effect
on tire grip, as it creates micro interlocking with rough asphalt."

should someone tell jobst?

jim really
that's what Jobst siad, no?

say, where's the spokes ?
new approach?

jim beam said:

Tosspot said:

http://www.schwalbe.de/gbl/en/tech_info/

Stumbled across this again, so I post it for posterity. Quite useful I
feel.

on the subject of tire tread and slicks:

"Even in wet conditions, on a normal, smooth road, a slick tire actually
provides better grip than a tire with a tread, because the contact area
is larger.

this is true though normally slicks are rather narrow tires, while
treaded are fair bit wider, so have a bigger contact area.

Quoted message said:

The situation is much different on a rough road and even worse on a dirt
trail as in these cases the degree of control provided by a slick tire
is extremely limited.

in pratice it's more complicated considering that the normal slippery
stuff in uk is mud and most tires tread will clog fairly quicly at which
point your back to square one, mud tire are a differnt kettle of fish.

Quoted message said:

A slightly serrated surface on the tire tread can have a positive effect
on tire grip, as it creates micro interlocking with rough asphalt."

certinaly a lot of road tires have a such a tread i guess shows any
wear...

Quoted message said:

should someone tell jobst?

roger
--
www.rogermerriman.com

datakoll said:

jim really
that's what Jobst siad, no?

no, he disavowed any tread on tires when he "invented" the slick. but
here we have a manufacturer who states the reasons why tread is actually
used. i guess no dirt ever finds its way onto the glass-smooth roads of
palo alto.

Quoted message said:

say, where's the spokes ?
new approach?

jim beam said:

datakoll said:

jim really
that's what Jobst siad, no?

no, he disavowed any tread on tires when he "invented" the slick. but
here we have a manufacturer who states the reasons why tread is actually
used. i guess no dirt ever finds its way onto the glass-smooth roads of
palo alto.

On a somewhat related note, I have recently switched to a new kind of
tire on my mountain bike (which I usually ride on city streets). I
had been using Avocet FasGrip City 26x1.9" tires on 45mm wide rims.
They were free-rolling, with a surprisingly taut ride quality at only
40 to 45 psi-- which I attribute to the tire cross-sectional shape
caused by the very wide rims.

In any case, the Avocet tires emitted a lot of fuss in hard turns,
squeaking and scrubbing and making a good deal of noise as they sought
out traction on the sides of the tread. Pretty much all my slicks and
semi-slicks do this to one degree or another, but these tires were
noisier and more conspicuous about hunting for purchase in turns. I
assumed it was because of their shortened contact patches compared to
my other bikes' tires, which are mostly fat to very fat 700c models,
and because of the long wheelbase and commensurately high typical lean
angle of my custom MTB. Before the Avocet slicks, I used 26x2.35"
Schwalbe Big Apples, which were comparatively cushier but not all that
much grippier.

I switched tires because after many years of wishing for such a thing,
I finally found a true street slick in 26x3.0" size:

http://www.choppersus.com/store/product/818/Tire-26-x-3-Kenda-Kraze/

These tires measure an actual 2.7" or so mounted on the same 45mm wide
rims. They have pronounced shoulders, like sporting motorcycle tires
or early production Tioga City Slicker MTB tires. Their sidewalls are
supple (considering) but their tread rubber is thick. I have run them
at pressures ranging from 16 to 32 psi, seeing no reason to use higher
pressure in tires so large.

The big Kenda tires are noticeably slower than the Avocet slicks,
which is what I expected given their pressure and tread thickness.
What I did not expect was the solid, silent, imperturbable grip that
the big tires offer in hard turns. They just grab the pavement
quietly and betray no signs of letting go. It's a very different
subjective sensation than that offered by any kind of knobbies or
siped tires as well as any slick tires I have tried recently.

Certainly the infrequent sipes in Kenda Kraze tires are nothing more
than aesthetic features in a bicycle application; I can't imagine that
they contribute to hard-surface grip in any noticeable way. The rest
of the tread surface is smooth and devoid of textural features. Even
so, the grip is like nothing else I have ever ridden. No amount of
grooving, file tread, or block tread elements could improve
meaningfully upon the traction these tires afford on dry pavement.
I've tried just about every kind of tread pattern ever offered for
city bike tires: ribbed, siped, herringbone, inverse, broad blocks,
chevron, brick, knurled, slick, you name it. Nothing else I have
tried approaches this level of grip. I'm very impressed.

Chalo

Chalo writtificated

Quoted message said:

I have run them at pressures ranging from 16 to 32 psi

Quoted message said:

What I did not expect was the solid, silent, imperturbable grip

Wheely wide tyre at a wheely low pressure = more grip than a ghecko on
superglue

Chalo said:

jim beam said:

datakoll said:

jim really
that's what Jobst siad, no?

no, he disavowed any tread on tires when he "invented" the slick. but
here we have a manufacturer who states the reasons why tread is actually
used. i guess no dirt ever finds its way onto the glass-smooth roads of
palo alto.

On a somewhat related note, I have recently switched to a new kind of
tire on my mountain bike (which I usually ride on city streets). I
had been using Avocet FasGrip City 26x1.9" tires on 45mm wide rims.
They were free-rolling, with a surprisingly taut ride quality at only
40 to 45 psi-- which I attribute to the tire cross-sectional shape
caused by the very wide rims.

In any case, the Avocet tires emitted a lot of fuss in hard turns,
squeaking and scrubbing and making a good deal of noise as they sought
out traction on the sides of the tread. Pretty much all my slicks and
semi-slicks do this to one degree or another, but these tires were
noisier and more conspicuous about hunting for purchase in turns. I
assumed it was because of their shortened contact patches compared to
my other bikes' tires, which are mostly fat to very fat 700c models,
and because of the long wheelbase and commensurately high typical lean
angle of my custom MTB. Before the Avocet slicks, I used 26x2.35"
Schwalbe Big Apples, which were comparatively cushier but not all that
much grippier.

I switched tires because after many years of wishing for such a thing,
I finally found a true street slick in 26x3.0" size:

http://www.choppersus.com/store/product/818/Tire-26-x-3-Kenda-Kraze/

These tires measure an actual 2.7" or so mounted on the same 45mm wide
rims. They have pronounced shoulders, like sporting motorcycle tires
or early production Tioga City Slicker MTB tires. Their sidewalls are
supple (considering) but their tread rubber is thick. I have run them
at pressures ranging from 16 to 32 psi, seeing no reason to use higher
pressure in tires so large.

The big Kenda tires are noticeably slower than the Avocet slicks,
which is what I expected given their pressure and tread thickness.
What I did not expect was the solid, silent, imperturbable grip that
the big tires offer in hard turns. They just grab the pavement
quietly and betray no signs of letting go. It's a very different
subjective sensation than that offered by any kind of knobbies or
siped tires as well as any slick tires I have tried recently.

Certainly the infrequent sipes in Kenda Kraze tires are nothing more
than aesthetic features in a bicycle application; I can't imagine that
they contribute to hard-surface grip in any noticeable way. The rest
of the tread surface is smooth and devoid of textural features. Even
so, the grip is like nothing else I have ever ridden.

great!

Quoted message said:

No amount of
grooving, file tread, or block tread elements could improve
meaningfully upon the traction these tires afford on dry pavement.

that's presumption - you haven't tested that.

Quoted message said:

I've tried just about every kind of tread pattern ever offered for
city bike tires: ribbed, siped, herringbone, inverse, broad blocks,
chevron, brick, knurled, slick, you name it.

but the tread pattern is not the only variable - these are not
"controlled tests".

Quoted message said:

Nothing else I have
tried approaches this level of grip. I'm very impressed.

Chalo

but on a clean dry road, you'd expect tread block distortion to have a
negative impact on traction wouldn't you? that's why slicks are used on
cars for racing, and car "performance" tires have bigger stiffer edge
blocks.

but when it comes to real world conditions, where grit, and mud wash
onto roads, tread becomes much more important. hence we have treaded tires!