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  1. #1
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    wrecking a tire possible with fluid based tubeless system

    http://www.nsmb.com/gear/tubeless_12_04.php
    I tried this conversion and everything worked until I landed a jump. The tire blew off.
    So I took al the muck out and wanted to install the tire with a inner tube but that wasn't possible anymore because the tire casing was stretched. So it wouldn't fit in the bed anymore.

    The tire is a Tioga factory DH 2.3 The tire was almost worn so thats why I tried the conversion on this tyre. But how is it possible that the casing got stretched?
    The rear works perfectly.

  2. #2
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    Quote Originally Posted by djamgils
    http://www.nsmb.com/gear/tubeless_12_04.php
    I tried this conversion and everything worked until I landed a jump. The tire blew off.
    So I took al the muck out and wanted to install the tire with a inner tube but that wasn't possible anymore because the tire casing was stretched. So it wouldn't fit in the bed anymore.

    The tire is a Tioga factory DH 2.3 The tire was almost worn so thats why I tried the conversion on this tyre. But how is it possible that the casing got stretched?
    The rear works perfectly.
    The tire bead is stretched or broken. A known issue with DIY tubeless. Dead tire.

    I do not recommend using any standard tire and/or rim without inner tubes.
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  3. #3
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    I am Currently running Tiogas on my two bikes using Stans Tubless rim strips.
    Two Red Phoenix 2.0s and Two 2.1 Tioga Factory Extreme XC tires. I have had no problems. I have pulled countless thorns out and have yet to get a flat while on the trail.
    I have been running these tires for about a year. Try the Stans rim strips. They work great.

  4. #4
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    Is it because of the DIY rim strip or would this also have hapened with a stans rim strip?

    I am going to try it with another set of tyres but then I will cut the innertube on the inside of the rim.

    My rear tyre still holds on.

  5. #5
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    Quote Originally Posted by djamgils
    Is it because of the DIY rim strip or would this also have hapened with a stans rim strip?

    I am going to try it with another set of tyres but then I will cut the innertube on the inside of the rim.

    My rear tyre still holds on.
    It is because you are using tires and rims that are not designed to be used without inner tubes. Sometimes it works, sometimes it does not. The type of rim strip used does not matter.
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  6. #6
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    and in wich way should the force excerted by the inner tube difer of the force excerted by the air directly on the tire?

    would the tire also blow of if I never used the tubeless system.

    (hope you understand it, I am dutch so my technical english isn't super)

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    Basically, a tubeless tire has an inner layer that would be the tube, but it is one with the casing of the tire. A non tubeless tire obviously doesn't have this, thus a generally thinner wall compared to its tubeless counterpart. There are certain laws of physics that apply here, such as some fundamental fluid dynamic/pressure laws where a fluid pushes against a uniform surface with equal pressure. When you take a drop of jump, or even simply sit on the bike, this equilibrium is broken and some areas receive greater force around the rim than others. Landing is a weird thing in that the are where the tire lands will tend to squish to one side, coupled with some compression of the contents of the tire, and a subsequent rebound through that path of least resistant where the bead has less force against the rim because it's being moved to the side. Then in an instant, the air burps out and with enough force to blow the tire off and stretch the bead. A tube inside a tubed tire equalizes the pressures, also preventing the burping.

    Tubeless is not a perfect technology yet, but in my opinion, going for lighter weight by using non tubeless tires is not the way to go. Little weight is saved and reliability is a crap shoot. We're all still doing the beta testing.

  8. #8
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    Quote Originally Posted by djamgils
    and in wich way should the force excerted by the inner tube difer of the force excerted by the air directly on the tire?

    would the tire also blow of if I never used the tubeless system.

    (hope you understand it, I am dutch so my technical english isn't super)
    I doubt if the tire would have blown off if only used with tubes.

    An inner tube contains the air. The surface of the tube presses the tire bead against the rim bead.

    Remove the tube and the air tries to push between the tire and rim beads. A DIY rim strip (includes commercial products) can make the bead interfaces even less positive (changes the contour) and sealants can act as a lubricant. Add some side force: Boom!
    Again, it may work, it may not.

    UST-type tubeless tires and rims have beads designed to lock together. Stronger tire bead. Bead contours that match. A strong mechanical seal and air tight without sealants or added rim strips.
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  9. #9
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    Cool-blue Rhythm Can't agree

    I have personal experience with tires "blowing off the rim" WITH tubes in them.. both MTB and 700c

    All you have to do with most tires is over-inflate them... even tubeless will blow off the rim with hi pressure.. Had a Specialized Resoultion Pro 2Bliss, blow off with 75psi... (65 max)..Others blew-off sitting in the hot sun...went overpressure

    Or have the tire bead not centered on certain old-style rims.. lets the tire move off center, the tire blows off.. just like taking it off without a tire tool

    Kevlar bead seem to be more prone (much more prone)

    The Tioga the "stretched-the bead", that tire was Defective... either the wire in the bead was not welded properly, or the Kevlar not made properly..It simple cannot "stretch". break yes, stretch no..

    And, the pressure exerted on every square mm of tire and rim is exactly the same with tubes and without... no difference..none... and the tube offers no resistance to "enlarging"

    I forgot, the usual way to break-a bead is by careless mounting,forcing the tire on using really strong tire tools, and not positioning the tire properly.. I have seen car-tire beads broken on a tire machine the same way..

    It might not show right away, particularly with lo pressure

  10. #10
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    Quote Originally Posted by theProfessor
    I have personal experience with tires "blowing off the rim" WITH tubes in them.. both MTB and 700c

    All you have to do with most tires is over-inflate them... even tubeless will blow off the rim with hi pressure.. Had a Specialized Resoultion Pro 2Bliss, blow off with 75psi... (65 max)..Others blew-off sitting in the hot sun...went overpressure

    Or have the tire bead not centered on certain old-style rims.. lets the tire move off center, the tire blows off.. just like taking it off without a tire tool

    Kevlar bead seem to be more prone (much more prone)

    The Tioga the "stretched-the bead", that tire was Defective... either the wire in the bead was not welded properly, or the Kevlar not made properly..It simple cannot "stretch". break yes, stretch no..

    And, the pressure exerted on every square mm of tire and rim is exactly the same with tubes and without... no difference..none... and the tube offers no resistance to "enlarging"

    I forgot, the usual way to break-a bead is by careless mounting,forcing the tire on using really strong tire tools, and not positioning the tire properly.. I have seen car-tire beads broken on a tire machine the same way..

    It might not show right away, particularly with lo pressure
    sorry professor but there are a few flaws in your logic
    all you have to do is overinflate? come on , you could blow any tire up if you overinflate it enough

    he didnt say the bead stretched, he said the casing. huge difference, ive seen plenty of reactions with rubber and solvents, and I know WTB voids the warranty if you use any type of liquid "sealant"

    the rest of your arguments are related to improper installation & bead breakage (which I already touched on)
    I also saw photos of a Kenda tire that both stretched and melted from an additive

  11. #11
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    Cool-blue Rhythm I don't think so..

    "The tire blew off.
    So I took al the muck out and wanted to install the tire with a inner tube but that wasn't possible anymore because the tire casing was stretched. So it wouldn't fit in the bed anymore.""
    ====
    I think this guy had a slight problem with terminology.. confusing casing with bead.., referring to the tire as the casing and the rim as the bead

    His says "..the tire casing was stretched. So it wouldn't fit in the bed anymore.""
    That says to me he meant the tire bead was stretched and would fit the rim bead anymore..because casing "stretch" would have no effect on mounting..,
    (I have been a tech and service writer most of my life, interpretation of customers complaints comes with the job)
    If the casing failed, it might be very soft near the bead and bulge out, but it probably would have failed under pressure, like a tube..or a rim/brake pad-cut sidewall and still wouldn't account for the tire blowing off the rim..unless the bulge was so bad it actually lifted the bead over the edge of the rim

    Seeing the tire would make this much easier to diagnose..

    In any case, I didn't address anything about casing failures from sealer.. only the "blowing off the rim, and then being unable to mount the tire afterwards..

    And in his case, unless the tire was defective, it sounds like the bead was damaged during installation..And since he said he couldn't mount it, not had a bulge and blew off when he tried to remount it, I still think it was a bead failure

    ==
    On the issue of tire-failure-with-sealer.. I know of Kenda warning. I also know Kenda has the poorest quality control of all the mfgs.. tires wobble, casings are malformed, rubber peels back at the bead area from very poor quality mold processes.and casings fail..Look very carefully at Kendas bead area.. on the inside with a bright light.porosity, loose rubber, you can peal the rubber off the bead with your finger-nail..and down into the inside of the tire. I no longer use them (I sold all 8 of the Negeval's and Blue-Grooves I had) they are junk and there are much better..(they are cheap)

    That said, I have never actually seen any failures from sealer,(not saying much) I run UST w/ Stans in Maxxis tube-type tires, after suggestions from about 5 different riders that this works, and talking to Stans.. Stans seems to have more chemicals than Slime, a very, very small amount of ammonia that is supposed to dissipate, but it seals rims better.and seals faster. I use Slime in my UST tires..The green-dots make it easier to see if you have had a puncture, and bead-sealing is not an issue..
    Been doing it for over a year.. with Michelin and Maxxis and absolutely no problem..

    Just my personal observed experiences, I am not an expert on this

  12. #12
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    Quote Originally Posted by theProfessor
    "The tire blew off.
    So I took al the muck out and wanted to install the tire with a inner tube but that wasn't possible anymore because the tire casing was stretched. So it wouldn't fit in the bed anymore.""
    ====
    I think this guy had a slight problem with terminology.. confusing casing with bead.., referring to the tire as the casing and the rim as the bead

    His says "..the tire casing was stretched. So it wouldn't fit in the bed anymore.""
    That says to me he meant the tire bead was stretched and would fit the rim bead anymore..because casing "stretch" would have no effect on mounting..,
    (I have been a tech and service writer most of my life, interpretation of customers complaints comes with the job)
    If the casing failed, it might be very soft near the bead and bulge out, but it probably would have failed under pressure, like a tube..or a rim/brake pad-cut sidewall and still wouldn't account for the tire blowing off the rim..unless the bulge was so bad it actually lifted the bead over the edge of the rim

    Seeing the tire would make this much easier to diagnose..

    In any case, I didn't address anything about casing failures from sealer.. only the "blowing off the rim, and then being unable to mount the tire afterwards..

    And in his case, unless the tire was defective, it sounds like the bead was damaged during installation..And since he said he couldn't mount it, not had a bulge and blew off when he tried to remount it, I still think it was a bead failure

    ==
    On the issue of tire-failure-with-sealer.. I know of Kenda warning. I also know Kenda has the poorest quality control of all the mfgs.. tires wobble, casings are malformed, rubber peels back at the bead area from very poor quality mold processes.and casings fail..Look very carefully at Kendas bead area.. on the inside with a bright light.porosity, loose rubber, you can peal the rubber off the bead with your finger-nail..and down into the inside of the tire. I no longer use them (I sold all 8 of the Negeval's and Blue-Grooves I had) they are junk and there are much better..(they are cheap)

    That said, I have never actually seen any failures from sealer,(not saying much) I run UST w/ Stans in Maxxis tube-type tires, after suggestions from about 5 different riders that this works, and talking to Stans.. Stans seems to have more chemicals than Slime, a very, very small amount of ammonia that is supposed to dissipate, but it seals rims better.and seals faster. I use Slime in my UST tires..The green-dots make it easier to see if you have had a puncture, and bead-sealing is not an issue..
    Been doing it for over a year.. with Michelin and Maxxis and absolutely no problem..

    Just my personal observed experiences, I am not an expert on this
    after I posted to you I went back and read the link in his OP, no wonder it failed, he mounted the tire inside the cut tube

  13. #13
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    Quote Originally Posted by djamgils
    http://www.nsmb.com/gear/tubeless_12_04.php
    I tried this conversion and everything worked until I landed a jump. The tire blew off.
    So I took al the muck out and wanted to install the tire with a inner tube but that wasn't possible anymore because the tire casing was stretched. So it wouldn't fit in the bed anymore.

    The tire is a Tioga factory DH 2.3 The tire was almost worn so thats why I tried the conversion on this tyre. But how is it possible that the casing got stretched?
    The rear works perfectly.
    I wouldnt try that setup on anything other than smooth doubletrack. you mount the tire inside the cut tube? and add some latex molding liquid
    an accident waiting to happen

  14. #14
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    Agreed.. but since I couldn't get Maxxis DHF, and HighRolller 2.5's in UST Maxi Pro 60 only 40d in the US, and would have to get them from Chainreaction in GB for about $50 shipping (good price on the tires though..)

    I have two sets of wheels, Mavic 823 / Hope pro2 and Alabs....one set are UST Maxxis 40's with Slime the other set are MaxiPro 60's tube-type with Stans..

    When I wear the MaxiPro's out, I will probably get the UST ones..depends on the exchange rate when I need them

  15. #15
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    Well, it led to a good discussion anyway..

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    Good discussion. I am going to try the system with another front tyre but I am busy with school. It is possible the front tyre broke with putting the tyre on.

    The rear tyre still holds on.

    haha, on a dutch forum almost nobody responded to this.

    I noticed it with all my threads here that there are a lot of experienced people on this forum, only problem is that I cant see if they are 14 or 30 years old.

    On the dutch forums there are a lot of 14-18 years olds who talk like they know everything. I almost have a degree in mechanical engineering(in 2 weeks) so I think I have a little bit an idea of mechanics on a bycicle.

  17. #17
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    The Material Scientist in me is deeply troubled....

    ... about the so-called breaking of kevlar beads on tires. So I started to look some stuff up on Wikipedia, etc:

    http://en.wikipedia.org/wiki/Kevlar

    Text of intrest from Wikipedia:

    When Kevlar is spun in the same way that a spider spins a web, the resulting fiber has tremendous tensile strength (about 3 GPa). The fibers do not rust or corrode. When woven together, they form a good material for mooring lines and other underwater objects. In addition the material is lightweight, the relative density is 1.44.

    There are three common grades of Kevlar: Kevlar, Kevlar 29, and Kevlar 49. Kevlar is typically used as reinforcements in tires and other rubber mechanical goods. Kevlar 29 is used in industrial applications such as cables, asbestos replacement, brake linings, and body armor. Kevlar 49 is considered to have the greatest tensile strength of all the aramids, and is used in applications such as plastic reinforcement for boat hulls, airplanes, and bikes.

    Kevlar is susceptible to breakdown from ultraviolet light (such as sunlight) and hence is almost never used unprotected or unsheathed.


    BTW: 3Gpa tensile stress is equivalent to about 435,000 psi. Does anyone really think that they run tire pressures that would even remotely approach stresses that high under any condition at any location in the tire?

    Not even with a 10' huck with <2.0" tires at +60psi. And, certainly NOT when you mount a tire (I do have a convincing argument for this, but not the time to type it).

    Think before you type your answer.

    I might even believe that kelvar bead HELP keep tires seated because they do not stretch. So, my theory RE: tubeless burping, etc with UST vs regular tires takes a different engineering approach

    Instead of pursueing the argument about bead cords breaking, can we focus on tolerance stack up of rims and tires? 26" MTB rms have a tolerance in the ERD, every last single one of them.

    So do tires.

    So do rim cross section (i.e. bead profiles) extrusion processes.

    I bets dollars to doughnuts that each has a normal distribution. When you get a rim:tire combination that is large:large, you need pedros levers. When you get a small:small, you can mount a tire just by breathing on it. When you get a nominal:nominal, it's neither too big, nor too small.... in other words, in-spec.

    If you have to use pedros levers or find your self spending more than 5 minutes per tire (with associated cursing and sprained thumbs) due to tight installation, than I bet you are on the large:small (rim:tire)

    My suspicion is that burping comes from the bead moving IN TOWARDS the center of the rim -- creating VERY small a "momentary" gap that might or not not be catastrophic -- and NOT in (to center), up and over the bead. I really dobt that a tube prevents this tire movement, but does in fact force the tire BACK into position. If this gap is small, the air in teh tire would be moving at a very high velocity creating a vibration of the rubber in tehtire and hence, the "burp" sound. Think about how air sounds when released from a ballon.....

    Man... I gotta stop. This is an insane waste of corporate bandwidth...

    Anyone with a rebuttal?

    The next area of research will be tire sealant chemistry (ammoinia and latex) impacts on the elasticity of rubbers used in tires.... THAT should be fun....

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    Cool-blue Rhythm Yea I think so..

    Didn't go back and read all the posts on this one..

    Personal experience with Kevlar-beads and tube-less..
    Tends to agree with your assessment

    Rarely had a tire "burp".. run 2.5" wire-bead tires on Mavic 823 tubeless rims (quality is not a question)
    And I run LESS than 22 lbs in the front with both tubeless and non-tubeless wire-bead Maxxis, with Slime or Stans..
    I have run Specialized Resolution Pro 2Bliss.. 2.3's they have Kevlar beads
    Early last summer, after mounting one on the front rim and making sure it was properly seated all the way around on both sides, I misread the air-pressure in my air tank and ran it up to what I thought was 65psi to let it "stretch" (was more like 85psi)
    About an hour later, down it the garage working on my Ducati, I heard a bang.. Came back up to my dog on the couch looking very confused and green, Slime all over the ceiling, walls and floor..(very easy to clean fortunately, I had just painted)
    Now the tire was seated, for sure.."popped" twice on both sides
    I reseated it, and rode it for about 250 miles after that..
    The bead was not damaged
    So my guess is there is enough 'give' in the rubber in the bead area, to allow the Kevlar over the rim-bead.. (Aggravated by the lubrication of the Slime when I mounted the tire)

    And , i have had a similar thing happen with an "over-pressure" when mounting a Kevlar tube tire in a hurry.... destroying the tube and not damaging the tire..and I have been running Kevlar beads since the 1980's
    And I have watch 700c Kevlar s blow of the rim sitting in the hot-sun and going overpressure..

    Kevlar is nice for a "folding-spare", and its a bit lighter.. but I will take wire-beads for the reliability
    --
    By the way, I have been mounting tubeless tires on cars, trucks, and motorcycles for the last 40 years...

  19. #19
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    HA!

    If the Professor agrees, then I MUST be right!

    Shiggy?

  20. #20
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    Yet another potential reason for burping with tubeless......

    bent rim channel - fixable?

    Probably no sealant can overcome this. Also, while tires can "absorb" some amount of this tolerance mis-match, there are practical limits.

    I bet this dude crunched the side wall of this tire when this happend creating a point of potential failure that could be exacerbated by sealant, etc....

  21. #21
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    Quote Originally Posted by yogidave
    ... about the so-called breaking of kevlar beads on tires. So I started to look some stuff up on Wikipedia, etc...
    That would be all well and good if the Kelvar bead was one continuous piece. It is not.

    At best it has several strands that are wrapped around the bead and may or may not be wrapped tightly. If not, it can "stretch," settle in, after inflation.

    At worst, the tire uses a segmented kelvar bead with no single piece reaching clear around the bead. Just short overlapping pieces. This can definitely stretch and break.

    How can you tell the difference? You can't.

    Then add it the fact that some folding bead tires do not even use kelvar but lesser (weaker and/or more elastic).

    Also note that Hutchinson had to resort to carbon fiber in the beads of their tubeless road tires because Kelvar alone was not up to the stresses.
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  22. #22
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    Quote Originally Posted by yogidave
    Yet another potential reason for burping with tubeless......

    bent rim channel - fixable?

    Probably no sealant can overcome this. Also, while tires can "absorb" some amount of this tolerance mis-match, there are practical limits.

    I bet this dude crunched the side wall of this tire when this happend creating a point of potential failure that could be exacerbated by sealant, etc....
    You did not even read that thread!

    It is a brand new, unused wheel that was damaged during shipping.
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  23. #23
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    Quote Originally Posted by yogidave
    ... The next area of research will be tire sealant chemistry (ammoinia and latex) impacts on the elasticity of rubbers used in tires.... THAT should be fun....
    Have fun looking for the specific rubber compounds and bonding agents used in each factory and for each model tire. They are far from the same and sealants (with or without ammonia and/or latex) affects them differently.
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  24. #24
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    OOOOPs!

    Quote Originally Posted by shiggy
    You did not even read that thread!

    It is a brand new, unused wheel that was damaged during shipping.
    Shiggy, you are correct, I did not see that the wheels where new. Good catch. Idoes appear that I did not folllow my own advice about thinking before I type. My Bad.

    But while we are on the subject, suppose a rim had a ding in it like this... the ding would/should/could preclude the tire bead form properly seating itself and be more prone to burping.

    Would you disagree?

    My thought is that a brand new rim (or one that has not been abused) might be better at sealing up.

  25. #25
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    Retort, Retort!

    Quote Originally Posted by shiggy
    That would be all well and good if the Kelvar bead was one continuous piece. It is not.

    At best it has several strands that are wrapped around the bead and may or may not be wrapped tightly. If not, it can "stretch," settle in, after inflation.

    At worst, the tire uses a segmented kelvar bead with no single piece reaching clear around the bead. Just short overlapping pieces. This can definitely stretch and break.

    How can you tell the difference? You can't.

    Then add it the fact that some folding bead tires do not even use kelvar but lesser (weaker and/or more elastic).

    Also note that Hutchinson had to resort to carbon fiber in the beads of their tubeless road tires because Kelvar alone was not up to the stresses.
    Great point about segmented/discontinuous beads.... if that is the case, the bead probably will stretch. Not the kevlar, but the rubber. The kevlar cords might move relative to one another.

    You probably know WAY more about tire construction than most on the forums, so I am not directing this at you....

    However, my comments came from 2 pieces of information.
    1. Kevlar fibers DO NOT stretch. Go to the DuPont website and read this. Now, yarns made of discontinuous fibers might stretch; that is different.
    2. I have kevlar beaded tires (WTB) that I have been riding for almost a year and they are no easier than day one to put on and take off the rim (Velocity VXC). Same tire, same rim. PITA every time. Iknow, I know, this doesn't constitute extensive data, but still, it makes me think.... But maybe others have seen there tires get "looser" over time.... Maybe.

    After reading your comments, I kept digging. I found one website that suggested mounting tubeless tires with high pressure (60psi) during installation not to "stretch the bead", but rather to allow the rubber at the bead (deformed from being folded) to relax, settle into the rim bead, what ever you want to call it. This makes WAY more sense to me.

    Now, I don't have extensive data collected on the frequency of bead breaking (nor have I ever seen one break), but it seems unlikely to be honest. Data is data and I'd be more than happy to change my mind with the right data.

    For road tubeless, the stresses on the tire are SO much higher than in MTB tires. The math would show that a 23mm wide road tire has roughly 1/2 the surface area of a 2.3" MTB tire. And, add to that, the pressure in a road tire is roughly 4x that of MTB tire. So, we essentially talking about 8x the force on the bead of a road tubeless. The Dupont Kevlar spec actually shows some data for carbon fiber and it is roughly equivalent (actually about 15% less) in tensile strength to kevlar. CF is 3x the modulus of kevlar.....

    But I digress.......

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