steve_wmn

What is the real difference between a high TPI count road tire and a low count one, other than price? The marketing department will of course tell you that it makes a huge difference in suppleness, ride quality and strength. But I'm skeptical. As far as I can tell one deflated, kevlar beaded road tire is just as flaccid as the next and I have a hard time believing that the minute differences between them deflated suddenly becomes significant when 100 psi of air is added to them. The air still generates 99% of the rigidity of the tire, as far as I can tell. Furthermore I have a hard time believing that the cotton/silk/nylon/whatever cloth in the sidewall influences the rigidity under compression much at all anyway. I can see a thinker coating of rubber making a structural difference in the sidewall but a simple TPI count just doesn't mean anything as far as I can see.

So is this just plain old "more is better" marketing, or is there a science to it that I haven't seen yet?

53-11_alltheway

This is proven in labs though. There is a difference in rolling resistance.

Of course whenever you make the sidewall/tread thinner (to reduce "friction") the tire wears out quicker.

darkmother

Less rolling resistance generally, and better puncture resistance, in my experience. In this case, more is more.

martin_j001

This has been my experience in most cases too. I also find that the higher the thread count in the tires I've tried (limited to Hutchison, Michelin and Vittoria), the higher thread count tires seem to ride a bit nicer as well--I currently use Vittoria Rubino Pro's, but used to ride the Open Corsa for a few years--very nice tire, but pricey to replace (in my opinion). The downside is that the tires tread may not last as long, but your mileage may vary

baxtefer

in general higher TPI=more supple. in general.....
HOWEVER. There is no accepted standard as to how TPI is measured. some manufacturers use, say 60 TPI casings and call it that, 60TPI. some compaines use 4 layers of 60TPI casing and call it....240TPI.

53-11_alltheway

I never heard of that, but I wouldn't doubt it.

They have been lying about sizes too (listing 23mm tires as 25mm so they can look lighter on paper when compared to other 25mm tires)

operator

All of this is a non issue when you run 10 dollar tires that last forever.

steve_wmn

Could you cite your references? I read the recent thread on latex inner tubes and as near as I could tell by reading the table and guessing at what the German language headings meant, they actually measured rolling resistance on some tubulars and found what might be significant differences or might not be. I want to see double blind research studies on ride quality and "suppleness" and/or measured rolling resistance values for two slick tires with nothing to distinguish them but sidewall thread count.

53-11_alltheway

I'll try to find you some.

They can measure rolling resistance in a lab, but the "subjective" studies (ride quality,etc) that I think you want don't exist as far as I know.

darkmother

The way I look at it is this: The tire plies are structural, they provide the tensile strength that supports the air pressure in the tire. It seems to me that cheaper tires come with a more sparse open weave, then make up for some of the reduced strength with thicker rubber. The rolling deformation thicker rubber is largely what contributes to rolling resistance, because the rubber heats up when deformed by the contact patch.

If you want to make a really fast tire, it has to have a thin rubber tread, and a supple, strong casing to support the high pressures that limit tire deformation. Higher thread counts help achieve these goals. Think of a thick, solid core wire, compared to a standed wire of the same guage. The finely stranded wire is way more flexible, even though the X sectional area, and material is the same.

53-11_alltheway

https://www.schwalbetires.com/new_high_end.html

"The flexible carcass reduces rolling resistance by approximately ten per cent"

This is pretty much what I keep on reading about. Those tests in german magazines like tour for example also
tend to have higher TPI tires come out with lower rolling resistance.

Obviously the design of the tire as whole matters the most, but the flexibilty of the tire carcass is one factor that plays into the whole picture.

Here is an answer form Leonard Zinn (scroll down) https://www.velonews.com/tech/report/...es/7508.0.html

HiYoSilver

Great link, but say for example the touring marathon plus have a load limit of 95 for 700x28. Sounds like need to go wider for bike+rider+load greater than 190lbs.

53-11_alltheway

I think as long as you aren't "bouncing around" higher pressures are better. My own subjective opinion is that
the high end tires (which happen to be higher TPI as well) let me go to higher pressurres without losing smoothness.

HiYoSilver

psi is 55-100, I think Max load is weight not pressure.