[amnonis]

I know that it sounds like a stupid question but it isn't.
Lets take the most popular DH tires - Maxxis for example.
Why does Maxxis bother producing those Minion 2.5 UST version. what is it good for? Most people I know that riding Tubeless are using 2plys anyhow. The UST aren't lighter (I checked few times and they are 50 grams lighter or even heavier) and they much more vulnerable to pinch flat. Regular 2plys has no problem with sealing comparing to UST. Am I missing something here?
Anyhow in case there is some tiny change in the tire edge, why does Maxxis not producing UST with 2ply sidewalls?
Does the other companies has different sidewalls when comparing UST to 2ply?

 

[norbar]

Last time I tried 2ply ust maxxis they were a bit more hassle to settle and I've had some problems with it. No problems yet with the ust ones.

 

[ilfreerider]

the thing is , there is no 2ply ust maxxis !
it seems that the dh ust casing is different (weaker) than the regular 2 ply dh casing.

 

[DirtyMike]

UST tire/wheel combo has a couple benefits. First off, the overall weight compared to a wheel, dh tube, and tire is lighter. UST tires dont need to be a massivly beefy casing, the biggest reason for dual heavy duty casing tires is to protect the tube from pinching. The USE tire has an inner liner that seals and holds air, just like a car tire, so there is no longer a tube to pinch. It eliminates Pinchflats while riding, SUpposedly its a more supple ride<cant tell myself, others swear by it>. You can run lower pressures in muddy/nasty conditions fo more traction, I have run mine as low as 18 psi when on a rain ride.

 

[yd35]

in my experience, ust tires seat more easily on tubeless rims. while i can get a ust tire to seal on my 823 with a hand pump, i have to use an air compressor to get any non-ust tire to mate correctly with the same rim. maxxis ust and non-ust offerings weigh about the same but some tubeless offerings have the advantage of significantly less weight, ie the schwalbe offerings, muddy mary, big betty, etc.

 

[nelsonjm]

Don't they say they have some friction advantage too? Something about the tube and tire rubbing against each other that kills energy?

I remember someone described it here with a wood analogy. Tubed tired were described as two 2x4s tied together while the tubeless was just a single board.

edit:
Don't the ust tires have a different (stronger?) bead too?

 

[norbar]

UST tire/wheel combo has a couple benefits. First off, the overall weight compared to a wheel, dh tube, and tire is lighter. UST tires dont need to be a massivly beefy casing, the biggest reason for dual heavy duty casing tires is to protect the tube from pinching. The USE tire has an inner liner that seals and holds air, just like a car tire, so there is no longer a tube to pinch. It eliminates Pinchflats while riding, SUpposedly its a more supple ride<cant tell myself, others swear by it>. You can run lower pressures in muddy/nasty conditions fo more traction, I have run mine as low as 18 psi when on a rain ride.

I think you mistunderstood the poster. It was about why use ust when you can go tubeless with normal tires.

 

[ilfreerider]

havn't you guys notice a strength difference between the ust dh (weak) and the 2ply casings (very durable) ? why bother with a different casing if its weaker ?
as for mounting , i always thought that the difference in the ease of mounting comes from the lip structure ,and not the material . am i wrong ?

 

[davet]

The UST aren't lighter (I checked few times and they are 50 grams lighter or even heavier) and they much more vulnerable to pinch flat.

where did you check weights?

I've weighed multiple regular Minions and multiple UST Minions. The regular tires ranged from 1250-1290g ( think I weighed around 6 or so) and the UST tires weighed between 1120 and 1150 (out of 4 tires weighed)

I ran UST tires on UST rims with no sealant at all without issue saving another 60 or so grams.

The only issue I've seen with the Maxxis UST tires is using them with 823 rims. Some users (myself included) experienced bead cuts from the edge of the rim. The sidewall strength is the same as the regular non-ust tire, the difference is in the bead area where the UST tire is thinner.

 

[dhkid]

i think you have a very valid point. maxxis ust tires are weak sauce.

here is my little theory on what's going on. first of all, the kevlar beads, they are there for a good reason, they dont get kinks like wire beads and make inflation far easier. down side, they aren't as rigid as wire beads, are more expensive.

as for the soft casing, if i am not mistaken they also have a higher tpi than the dual ply dh tires. they probably did this to build on the advantage of tubeless tires being able to deform more and hence more traction, even at higher tire pressure. the down side of this is combined with what seems like a softer rubber in the casing, makes it easy to rip and tear. also folds over easier with side loads, hence why a lot of world cup riders dont like them.

the main difference between the tubeless and tubed tires will be the bead, which wont be hard to change really and make all tires tubeless like how michelin does it. a reason why they dont want to combine the two tires into one is probably due to economical reasons, make more profit on a certain tire or something like that.

another thing is that they probably know about the problems, but cant be bothered to change anything because there is no pressure to. just keep pumping them out and people will still buy them.

my personal favourite non ust tires to set up and use tubeless are intense tires. they have a very good bead that seals well, so you dont need to use much sealant. that combined with slime instead of stans, makes it easy to clean, non smelly and messy ect.

 

[amnonis]

http://www.maxxis.com/Bicycle/Downhill/Minion-DHR.aspx
UST 1300
2ply 1350

 

[wood booger]

A true UST tire is supposed to hold air without any sealant when used w/ a UST rim, a "normal" tire run tubeless will not. This is the main difference. UST tires are airtight (in theory).

Most people still use some sealant in any tubeless system to help prevent flats by thorns, etc.

 

[amnonis]

What is the advantage of a tubeless tire?
Answer:
Tubeless tires allow you to run lower air pressure without having to worry about pinch flatting a tube. This allows for maximum traction because you have more surface area contact with the ground.
What is a 2-ply (or) dual-ply DH casing?

What is a 2-ply (or) dual-ply DH casing?
Answer:
Two 60 tpi (threads per inch) casings vulcanized with butyl rubber and reinforced sidewalls make up Maxxis downhill casings, which are world renowned for performance and reliability. Our DH casings provide more stability at high speeds and allow for lower air pressure without the risk of pinch flatting.

What does TPI stand for?
Answer:
TPI stands for threads per Inch. It defines the number of threads contained in one inch of the tire casing. The lower the number of TPI, the larger the gauge cords in the casing. Thus, the more durable the tire becomes. The higher the TPI, the more lightweight the tire becomes and the more supple the ride of the tire. The majority of our tires are 60 TPI, and our race tires are 120 TPI.

What are Butyl Inserts?
Answer:
Butyl inserts are pieces of butyl rubber wrapped around and placed in between the two overlapped 60 tpi layers, midway through the sidewall in our 2-ply casings. The inserts add strength to the sidewall and add stability to resist pinch flats.

What is a Kevlar (DuPont) Belt?
Answer:
The specially formulated Kevlar (DuPont) belt is a breaker ply that is positioned between the layers of the casing. Kevlar provides maximum puncture resistance in the most unpredictable conditions. The RE-Fuse and Overdrive models utilize this technology.

 

[amnonis]

What Maxxis saying regarding their UST tires
http://www.maxxis.com/Bicycle/Downhill/Minion-DHF-UST.aspx
TPI=27
Bead = foldable -> Kevlar (DuPont) Belt
2-ply DH casings with butyl protected sidewalls

and regarding their DH 2ply
http://www.maxxis.com/Bicycle/Downhill/Minion-DHF.aspx
TPI=60
Bead=wire
2-ply DH casings with butyl protected sidewalls.

So it seems like they are producing what I'm looking for - 2ply UST but somehow I think this is a typo since I never saw this 2ply UST tire

 

[buildyourown]

UST tires can seal on a UST rim without any rim strip or sealant. If you do run sealant, you need way less since you only need it for puncture repair, not general air tightness and bead sealing. This means your finished setup is much lighter (ie no rim strip, 75% less sealant.)