Tire Thread Count - What difference does it make?

[Bestest Handsan]

I understand what a threadcount is on bicycle tires, but
what I don't know is the reason behind low and high
threadcounts. What is considered a high count anyway? If
someone could point me to some reading material is would be
greatly appreciated.

 

[carlfogel]

Originally posted by Bestest Handsan
I understand what a threadcount is on bicycle tires, but
what I don't know is the reason behind low and high
threadcounts. What is considered a high count anyway? If
someone could point me to some reading material is would be
greatly appreciated.

Dear Asbestos,

A high count in a tire thread is probably anything
over two dozen posts--

Oh, sorry, you mean tpi.

Jobst Brandt offered this reply to a comment:

[Marco suggested:]
>>>> So pick just about any tire with a high tpi
>>>> count for durability and puncture resistance,

[someone, possibly Jobst, inquired:]
>>> Would you say WHY you think this.

[Marco fantasized:]
>> Finer threads are weaker threads. They cannot
>> be more durable ( look at the Conti sidewall
>> comments posted all the time for starters )
>> and cannot be more puncture resistant unless
>> the tread is stronger with more resistant
>> rubber components holding it into a casing.

[Jobst cleared up the confusion:]
> think you'll find that high TPI tires have uniformly
> higher burst pressures than the "kite string" tires.
> there may be exceptions but the fine cord is usually
> higher strength fiber than the fat cord cheap tires.
> the fine threads make a far thinner casing that flexes
> with little losses. This is apparent from rolling resistance
> curves that show high TPI tires have low rolling resistance
> and are relatively unaffected by inflation pressure (lots
> of flex to little flex). You can draw your own conclusions
> about individual brands and their side wall failures.

http://yarchive.net/bike/tire_cords.html

Apparently, fat-cord tires use cheap, weak, kite-string
stuff. High tpi tires use more expensive, stronger, thinner
stuff that flexes with little energy lost.

Think thin silk thread versus coarse cotton yarn, and
you'll probably be on the right track [pun].

Carl Fogel

 

[Jobst Brandt]

Bestest Handsander writes:

> I understand what a thread count is on bicycle tires, but
> what I don't know is the reason behind low and high thread
> counts. What is considered a high count anyway? If someone
> could point me to some reading material is would be
> greatly appreciated.

The fatter the casing cords the fewer there are per inch as
in TPI or threads-per-inch. The thicker the casing the
greater the casing stiffness and therefore the grater the
rolling resistance. Rolling resistance in tires is caused by
flexing the tire casing, tube, and tread... and in the case
of a tubular tire, the viscous motion between tire and rim
in the rim glue.

If you look at the RR curves at:

http://www.terrymorse.com/bike/imgs/rolres.gif

You'll find characteristics of various tires. Tire brand and
model is immaterial but the shape of the curves isn't. As
you can see, the tire with the highest RR is also one that
benefits the most from higher inflation pressure but it
never gets as good as the best. You can almost estimate the
TPI of the lower tires from their RR curves, the best tires
benefitting less from higher pressure than the thick casing
ones, that usually also have thicker tread.

Flexibility in tire casings goes parallel inversely with
rolling resistance.

Jobst Brandt [email protected]

 

[Vizzutti]

What they've said about casing flexibility and rolling resistance is correct, but I'd add that a high thread count per inch also makes a huge difference in comfort over cheap tires, at least with an aluminum frame. Vortezza (sp?) has some 290 tpi tires on sale regularly for $20 if you are looking. They are awesome.

 

[Vizzutti]

Sorry. The tire I like is a Vittoria, not Vortezza.

 

[Charles Ramsey]

If you get a cut in a sidewall with a thread count over 66
tpi it will often rip like a piece of fabric making it
useless a low thread count tire will get you home on a tour.

 

[Paul Southworth]

In article <[email protected]>,
Bestest Handsander <[email protected]> wrote:
>I understand what a threadcount is on bicycle tires, but
>what I don't know is the reason behind low and high
>threadcounts. What is considered a high count anyway?

Low is often around 60 tpi; high more like 120+

--Paul

 

[Drs]

Vizzutti <[email protected]> wrote in message
[email protected]
> What they've said about casing flexibility and rolling
> resistance is correct, but I'd add that a high thread
> count per inch also makes a huge difference in comfort
> over cheap tires, at least with an aluminum frame.
> Vortezza (sp?) has some 290 tpi tires on sale regularly
> for $20 if you are looking. They are awesome.

Is that a genuine 290tpi? For example, Continental routinely
misrepresent their thread counts because they add up the
TPIs of all the carcass layers of one tyre.

--

"I'm proud that I live in a country where witnessing two
hours of bloody, barbarous torture in gloating detail is
considered indicia of religious piety, whereas a mere second
gazing upon a woman's breast is cause for outraged
apoplexy." Betty Bowers,
http://www.bettybowers.com/melgibsonpassion.html

 

[Chalo]

[email protected] wrote:

> The fatter the casing cords the fewer there are per inch
> as in TPI or threads-per-inch. The thicker the casing the
> greater the casing stiffness and therefore the grater the
> rolling resistance.

All else equal, a thin casing fabric will be more supple
than a thick one, and a high TPI fabric will be thicker than
a low TPI fabric, but that isn't the only pertinent
variable, is it?

For instance, a high TPI tire with relatively thick or
high-hysteresis tread rubber would likely have higher RR
than a low TPI tire with thin or low-hysteresis rubber,
wouldn't it?

Likewise, a multi-ply tire made of a fine casing fabric
would tend to have higher RR than a tire with a single pair
of coarse plies, right?

I have suspected for some time that TPI is overrated as an
indicator of rolling resistance. I would like to find some
authoritative information to either confirm or refute my
suspicion.

Chalo Colina

 

[Jobst Brandt]

Chalo Colina writes:

>> The fatter the casing cords the fewer there are per inch
>> as in TPI or threads-per-inch. The thicker the casing the
>> greater the casing stiffness and therefore the grater the
>> rolling resistance.

> All else equal, a thin casing fabric will be more supple
> than a thick one, and a high TPI fabric will be thicker
> than a low TPI fabric, but that isn't the only pertinent
> variable, is it?

Actually it is the opposite. The greater the TPI (threads
per inch) the thinner the cords and therefore the thinner
the tire casing can be. Since this requires a strong
filament that is more expensive than a coarse one,
manufacturers who make high TPI tires generally don't equip
them with heavy, thick tread, just as one doesn't use huge
knobby SUV tires on a high performance sports car.

As I said, its the amount of elastomer and cord thickness
that makes the tire less pliable and therefore have more
losses in bending, the cause of rolling resistance.

> For instance, a high TPI tire with relatively thick or
> high-hysteresis tread rubber would likely have higher RR
> than a low TPI tire with thin or low-hysteresis rubber,
> wouldn't it?

That depends on how the casing is built but that is what I
would expect from such an unlikely combination.

> Likewise, a multi-ply tire made of a fine casing fabric
> would tend to have higher RR than a tire with a single
> pair of coarse plies, right?

Only if the casing were thicker assuming the tread and inner
tube were the same.

> I have suspected for some time that TPI is overrated as an
> indicator of rolling resistance. I would like to find some
> authoritative information to either confirm or refute my
> suspicion.

I think it is generally the best indicator. Clement made two
tires on the same casing. One was called Paris-Roubaix, the
other Campionato del Mundo. The Paris-Roubaix, being for a
one day classic had a narrower and thinner tread strip while
the Campionato del Mundo, that was designed for stage races
over the Alps with mostly still unpaved roads had a tread
strip that went far up the sidewall and was nearly twice as
thick as that of the Paris-Roubaix in the center.

Avocet had a 23mm Criterium and TT tire on the same casing,
also with the thinner, lower RR tread on the TT.

For me the TPI tells me that I'm getting the lowest RR
casing and the tread thickness gives me durability. The two
should not be confused. Therefore, TPI IS the arbiter in the
evaluation.

Jobst Brandt [email protected]

 

[Chalo]

[email protected] wrote:

> Chalo Colina writes:
>
> > All else equal, a thin casing fabric will be more supple
> > than a thick one, and a high TPI fabric will be thicker
> > than a low TPI fabric, but that isn't the only pertinent
> > variable, is it?
>
> Actually it is the opposite. The greater the TPI (threads
> per inch) the thinner the cords and therefore the thinner
> the tire casing can be.

That's what I meant; I just said it backwards.

Thanks for the information.

Chalo Colina

 

[Andres Muro]

I own tires with 120 count and with 66 thread count. I
really can't tell the difference. Also, I usually get about
the same amount of flats with both. When I buy a tire, I try
to go for weight and price. I hate to pay anything more than
12.00 bucks, so I look for sales. I usually aim at about 260
to 300 grams tires anywhere between 23 and 25 width. If I
can find a heavy tire with kevlar beads at this weight, I go
for them cause I assume the weight goes into the casing.
Right now I own some IRC triathlon with kevlar belts with
120 tpi, and some victoria action tires with 66 tpi. They
weigh close to 300 grams. I can't tell any difference.
However, I haven't tried to ride one after the other to feel
differences nor have I tried different PSI. I think that I
go just as fast. I have no problem keeping up with my
friends and making them hurt on flats, but as soon as we get
to the hills, they start dropping me like a rock. It doesn't
matter what I am riding or what tires I use. Oh, I've
forgot, I used from latex to heavy duty tubes, tubes with
slime, and tubes surrounded by a second tube. I can't tell
the difference either. Right now, I stick to the chepest
butyl tube that I can find. I usually use tires until there
is nothing left. If a tire gets a big tear, I cut a plastic
cup and use the plastic to boot it. I get rid of tires when
I have two or three boots.

As you can see, my method of choosing and evaluating tires
is very scientific, of course.

Andres

[email protected] (Paul Southworth) wrote in
message news:<OBIac.2031$WC3.18385@ord-
read.news.verio.net>...
> In article <[email protected]>, Bestest
> Handsander <[email protected]> wrote:
> >I understand what a threadcount is on bicycle tires, but
> >what I don't know is the reason behind low and high
> >threadcounts. What is considered a high count anyway?
>
> Low is often around 60 tpi; high more like 120+
>
> --Paul

 

[x]

RE/
>I assume the weight goes into the casing. Right now I own
>some IRC triathlon with kevlar belts with 120 tpi, and some
>victoria action tires with 66 tpi. They weigh close to 300
>grams. I can't tell any difference.

Maybe its different for skinny high pressure tires.

I run 55/55 tires at about 35 psi. The ones I like best are
130 tpi WTB Mutano Raptors. I've got another set that are 60
tpi (Heng Shin SemiSlicks).

The 130 tpi tires seem to roll a *lot* easier than the 60's
- even on a paved surface - and the 130's have a lot more
tread on them.

OTOH, I'm one of those people who will swear that their car
runs better after being washed...so maybe my comparison
isn't very scientific either...
--
PeteCresswell

 

[Jobst Brandt]

Pete Cresswell writes:

>> I assume the weight goes into the casing. Right now I own
>> some IRC triathlon with Kevlar belts with 120 TPI, and
>> some Vittoria action tires with 66 TPI. They weigh close
>> to 300 grams. I can't tell any difference.

> Maybe its different for skinny high pressure tires.

> I run 55/55 tires at about 35 psi. The ones I like best
> are 130 TPI WTB Mutano Raptors. I've got another set that
> are 60 TPI (Heng Shin SemiSlicks).

Kevlar is notorious for bad RR in tire casings and I'm not
aware that anyone is making a Kevlar tire , only Kevlar
inlays as a belt under the tread. Even these produce
measurably poorer RR and that is why they are so uselessly
thin. They won't stop thorns either just as a sewing needle
will easily go through a bullet proof vest.

> The 130 TPI tires seem to roll a *lot* easier than the
> 60's - even on a paved surface - and the 130's have a lot
> more tread on them.

> OTOH, I'm one of those people who will swear that their
> car runs better after being washed...so maybe my
> comparison isn't very scientific either...

That's a good survey not to be ignored. Just ask the guy
in his freshly washed and waxed car if it doesn't feel a
lot better.

Jobst Brandt [email protected]

 

[Douglas Landau]

[email protected] (andres muro) wrote in message news:<[email protected]>...
> I own tires with 120 count and with 66 thread count. I
> really can't tell the difference. Also, I usually get
> about the same amount of flats with both. When I buy a
> tire, I try to go for weight and price. I hate to pay
> anything more than 12.00 bucks, so I look for sales.

I'm with you. Seems like there's a well-regarded tire on
sale for a great price often enough at either nasbar or
performance that if I buy four of them, I'm good until the
next good deal comes along.

Right now I'm riding Panaracer Stradius Elites, which I
think feel stickier but also heavier and not quite as free-
rolling than the last sale tire I tried which was Michelin
Hi-Lite Prestige. Gonna order some of the $13 Conti 3000s on
sale at performance right now.

I think Mike J said recently that people usually stick with
whatever came on their bike. Definately true of me. All I
rode for the first five years was Conti 2000s. I am now
enjoying trying out different tires -- but although it's fun
and interesting, I have not yet found any reason not to go
back to the 2000s, which are nice and light and always 20
bucks. Except possibly:
- Either it's my imagination or they slice on glass even
more than other tires (maybe just due to thin
tread/light weight)
- I never see them on sale. (Can't imagine why

-dkl

 

[Jobst Brandt]

Douglas Landau writes:

>> I own tires with 120 count and with 66 thread count. I
>> really can't tell the difference. Also, I usually get
>> about the same amount of flats with both. When I buy a
>> tire, I try to go for weight and price. I hate to pay
>> anything more than 12.00 bucks, so I look for sales.

> I'm with you. Seems like there's a well-regarded tire on
> sale for a great price often enough at either Nashbar or
> performance that if I buy four of them, I'm good until the
> next good deal comes along.

Oh but there is another side to this. A low TPI tire run at
high pressure will sustain broken cords when rolling over
angular obstacles
(1/2" piece of rock) and show only a distortion in the
tread. The casing being bias ply and only the inner layer
fails in such bending, a zig-zag in the tread pattern (if
there is one) is the only subtle indicator. In ant case,
the blowout may come later. This was also true in tubular
days when some riders bought "kite string" Clement-50's
instead of 120TPI silks. The 50 was called a good
training tire... which it wasn't. What a slug, too.

> Right now I'm riding Panaracer Stradius Elites, which I
> think feel stickier but also heavier and not quite as free-
> rolling than the last sale tire I tried which was Michelin
> Hi-Lite Prestige. Gonna order some of the $13 Conti 3000s
> on sale at performance right now.

I guess that depends on what you do with them. Just cruising
on smooth pavement shouldn't cause any problems.

Jobst Brandt [email protected]

 

[Douglas Landau]

[email protected] wrote in message news:<[email protected]>...
> Douglas Landau writes:
>
> >> I own tires with 120 count and with 66 thread count. I
> >> really can't tell the difference. Also, I usually get
> >> about the same amount of flats with both. When I buy a
> >> tire, I try to go for weight and price. I hate to pay
> >> anything more than 12.00 bucks, so I look for sales.
>
> > I'm with you. Seems like there's a well-regarded tire on
> > sale for a great price often enough at either Nashbar or
> > performance that if I buy four of them, I'm good until
> > the next good deal comes along.
>
> Oh but there is another side to this. A low TPI tire run
> at high pressure will sustain broken cords when rolling
> over angular obstacles
> (1/2" piece of rock) and show only a distortion in the
> tread. The casing being bias ply and only the inner
> layer fails in such bending, a zig-zag in the tread
> pattern (if there is one) is the only subtle indicator.
> In ant case, the blowout may come later. This was also
> true in tubular days when some riders bought "kite
> string" Clement-50's instead of 120TPI silks. The 50
> was called a good training tire... which it wasn't.
> What a slug, too.

Interesting.

I was unclear in the way I quoted Andreas. I did not intend
to comment on thread count. I was agreeing with how much he
likes to spend and his strategy of looking for sales.

> > Right now I'm riding Panaracer Stradius Elites, which I
> > think feel stickier but also heavier and not quite as
> > free-rolling than the last sale tire I tried which was
> > Michelin Hi-Lite Prestige. Gonna order some of the $13
> > Conti 3000s on sale at performance right now.
>
> I guess that depends on what you do with them. Just
> cruising on smooth pavement shouldn't cause any problems.

The Stradius elites are 126 TPI. My only experience with TPI
is having bought some 33 TPI Michelins. I hated them. They
were hard as a rock and slugs. I would not buy a tire with
anything less than 120 after that.

dkl

 

[John Roden]

I have been using some remarkable tires called a Specialized
Armadillo. They are virtually impossible to flat because
they are so thick, but going downhill they roll much slower
than regular old tires. I tried swapping wheels on a
training ride with a friend and whoever had the Armadillos
would end up loosing a bike length every 50 or so meters.

I use these tires because they are so tough, but always
assumed the very rigid casing is what caused them to roll so
slowly--am I correct in this assumption?

 

[carlfogel]

Originally posted by John Roden
I have been using some remarkable tires called a Specialized
Armadillo. They are virtually impossible to flat because
they are so thick, but going downhill they roll much slower
than regular old tires. I tried swapping wheels on a
training ride with a friend and whoever had the Armadillos
would end up loosing a bike length every 50 or so meters.

I use these tires because they are so tough, but always
assumed the very rigid casing is what caused them to roll so
slowly--am I correct in this assumption?

Dear John,

Actually, an incredibly rigid and resilient casing
(like steel) would reduce rolling resistance. Little
beyond magnetic levitation beats steel railroad
car wheels on steel rails for low rolling resistance.
(This is why no one worries about the rolling
resistance of the bicycle's hub bearings--the
metal rolling resistance is infinitesimal compared
to the clumsy tires.)

Given plenty of air pressure (a marvelous spring),
the same material (rubber isn't as good as latex),
and the same smooth tread (any pattern increases
rolling resistance by allowing extra squirm), what
matters is how thick the tread is and how high the
loss is in the casing--the thinner, the better.

Basically, the less material that you flex into an
endless bulge as the tire meets the road, the
less energy you waste distorting it. This is the
real advantage of light tires and light tubes, the
latter becoming part of the tire under normal
pressures.

Some materials absorb more energy as they
flex (rubber versus latex, for example), but
the big problem with your tires is likely just
that there's so much of them. Big soggy chunks
of rubber, kevlar, and cotton with block treads
squirming uselessly to the sides don't roll as
well as thin, smooth wafers of highly pressurized
latex and silk.

With luck, more learned types will expound on
the details and correct any misconceptions.

Carl Fogel

 

[x]

RE/
>Basically, the less material that you flex into an endless
>bulge as the tire meets the road, the less energy you waste
>distorting it. This is the real advantage of light tires
>and light tubes, the latter becoming part of the tire under
>normal pressures.

As long as the road is smooth....
--
PeteCresswell