Psimet2001 

That's a nice thought but it's never going to happen. Josh Poertner had a lot to say about the current state on the nerd alert podcast (latest one maybe). He is way more optimistic about all of it than I am. He touches on some legacy issues that will always be present and yet I still believe he lives in a rare world where there is way more control than what actually exists in real life.

The fact that many enthusiasts are running to hookless is way more upsetting to me now than it was. I really don't think most users really have any idea exactly how bad and uncontrolled of a situation it really is.

I was hoping Josh would rattle off a list of gains that hookless represents but even he said it's just simply manufacturing. This is the wheel equivalent of pressfit BB's and it makes me kind of queasy.

EDIT: I see the podcast linked above. It's worth a listen. If you're a staunch advocate of road tubeless on hookless rims then maybe you should take a moment and dull that enthusiasm. Fine if you feel like you've cross all your T's and dotted all your i's but coming out here on a forum and recruiting a ton of people that seem to know how to read but not think (trust me they end up walking in and saying they read all this online but don't really get it) is not something I would recommend.

Chilepines

Interesting thread (minus the bickering!) which I found after having a hookless blowout today - luckily not when I was on the bike.
Light Bicycle WR45 rim, 25 mm ID, with Specialized Sawtooth 700 x 38. This was the rear tire on a tandem. Tires have been mounted for a while and have just 2 rides on them. I pumped them to 65 psi today, but the tandem in the truck, and while sitting about 100 feet away thought I heard a gun shot! Pretty frickin scary in my mind. As far as I can tell, the tire is hookless compatible - but honestly that is hard to find. It is 2Bliss, so tubeless ready, but are they OK to use on hookless? If Specialized says yes or no I can't find it. I'm pretty sure the tire blew off because of the pressure, but 65 psi is not that high.
I have a set of Rene Herse Hurricane Ridge tires going on Enve AG25 wheels for a gravel bike. RH says the tire is tubeless compatible, but again it is not clear that they are hookless compatible.
So I don't know if this is officially a mess or if I would have sued someone if we crashed our tandem - but I really wish the tire didn't blow off today!

Racing Dan

Bummer.

According to Specialized your sawtooth tyre is hookless compatible, but lightbicycle quotes a 55psi (!) max pressure for your wr45 rim.

The ENVE AG25 rim is equally rated to only 55psi max, and RH seem to recommend against using the Hurricane Ridge on a hookless rim "that don’t meet the current standards". What ever that means.

It appears the before mentioned 72psi max pressure only applies to strict road rims, seeing both ENVE and Light bicycle quoting even lower numbers. - Imo, its safe to claim its a big fat mess and requires way too much homework to not get in trouble.

https://support.specialized.com/tire...s/gravel-tires

https://www.lightbicycle.com/700C-32...ompatible.html

https://www.enve.com/learn/tire-compatibility/

https://www.renehersecycles.com/new-...rance-casings/ (In the comment section)

chaadster

Standards and compatibility being a mess is one thing, but failing to know anything at all about what one is doing is something else.

I just don’t think it’s either desirable or reasonable to expect tire/rim compatibility to be idiot-proof.

Sy Reene

The max is the max, but even as it is for tubed tires, you can't put 23mm tire on a wide rim and blow it up to 116psi.

Mavic I think has the best charts for max out there, listing (as it should be) on all 3 factors.

Racing Dan

?! You are the only one talking about a 23mm tire on a wide rim at 116psi. Hardly relevant to the discussion at hand.


But yeah, its true a wide rim will reduce max pressure and wide hookless rim even more so. For instance a 28mm on 25mm hookless rim is 59psi max. The same tyre on a standard, hooked, 17mm rim is 105psi max. Almost double, leaving you with a much wider safety margin to you normal riding pressure and seating pressure.


That said, you should always adhere to what ever the actual manufacturer of the rim and tyre says is max, no matter what a generic chart says.

lessthanideal

FWIW I have seen three RH TC tires blow off three different tubeless rims in the last year.

35mm Bon Jon Pass off a Mavic Open PRO UST Disc (UST)
38mm Barlow Pass off of a Weareone Revive (hookless)
26" Natches Pass off of a Stan's Crest (BST)

All tires were new and fitted dry first to confirm the bead was evenly seated on the rim prior to adding sealant. All three blew off at pressures under 50psi. Two while the sealant (which was added through the valve) was sitting to properly seal and the third while the rider was on their first ride (luckily they did not crash).

In the past, I have run their tires tubeless with zero issues and have sold and set up exponentially more that did work than ones that did not. But there's definitely an issue here that simply isn't coming up with tires from larger companies like Maxxis, Vittoria, Challenge, and so forth.

I have long suspected that the more flexible casing of the RH tires (compared to other Panaracer made tires) allows the bead to stretch more. Bead shape and more importantly, stretch characteristics, are pretty key in tubeless tire design after all. I have noticed that Sim Works (also Panaracer made) does not endorse tubeless on their tires that do not use their stouter sidewalls despite having a bead that is the same dimensions as their TC offerings. Time will certainly tell what happens with the lawsuit. Regardless, the tubeless tire and rim world is certainly not as standardized as it should be and riders and shops should be diligent in talking to both rim and tire manufacturers to confirm compatibility and best practices.


YMMV of course.

Polaris OBark

Here is what is said in the first comment on your link, which I assume is what you are referring to:




I wonder if the person asking the question is the NMR guy?

chaadster

RHMV of course (Rene Herse Models Vary)! Standard, Extralight, and Endurance casing are not equally flexible, so which casing is at issue is probably relevant. I mean, I’m not sure what the mechanism is by which the casing inhibits bead stretch, but maybe. I mean, I know Sim Works have a nice writeup about tubeless compatibility issues here, but they don’t call out casing as a factor, so I wonder if tubeless concerns for lightweight sidewalls is more to do with permeability, both to air and sealant, which is something I’ve experienced with Herse extralight casings in contrast to Herse standard casings.

lessthanideal

It would make sense. Simworks calls out their Homage tires as specifically not TC. They use a different casing construction compared to their TC tires. I routinely handle both. The TC tires have sidewalls that are noticeably less supple. When you compare a standard casing Gravel King to a standard casing RH tire the differences in construction are pretty obvious too.


I should also add that all three tires I mentioned were the standard TC casing.

chaadster

As lessthanideal points out about Panaracer producing the tires for both SimWorks and Herse (as well as Ultradynamico, I think), “the current standards” Heine refers to are probably the ISO standards to which Panaracer builds tires and which do not have either specific tubeless or hookless standards. The SimWorks explainer link I included in my previous post talks about that element of the issue.

chaadster

Yeah, I just pulled off some GKs (to replace with American Classic) and was reminded of how rigid the GK gumwalls were. Thin, but rigid, which I guess helps keep the bead located on the rim, although I’d expect, given the ISO spec, that Panaracer tires are not great on low G-height rims, either. We seem to hear less about Panaracer blowoffs— dunno what you hear; you sound like an industry pro— but it may be more to do with market segment and the type of consumer than sidewall stiffness…

ThermionicScott 

Did they install "easily"? It seems like we should expect a certain minimum level of frustration if we want a combination that can't squirm around and blow off.

Sy Reene

True, but interesting to note that Chilepines scenario being discussed: "Light Bicycle WR45 rim, 25 mm ID, with Specialized Sawtooth 700 x 38" lines up on the Mavic ETRTO guideline chart referencing pretty much the same 55psi max you discovered that LB indicates. As the manufacturers get better about uniformly designing and speccing their products, a well-done 'generic' chart should be able to provide pretty good guidance, and the manufacturers should get to a place where their guidance is pretty much the same.

Polaris OBark

I get what you mean, but the only tire I have had blow off (a Vittoria) was an extreme struggle to mount. (It was tubed, and on a hooked rim as well.)

merlinextraligh

The ad damnum in the complaint, as quoted in the reports, makes no mention of any loss of wages, permanent impairment (other than scarring), loss of ability to earn income, or medical bills. or needed future medical treatment. All the elements of damage you would expect to be set forth in a typical complaint. The absence of such allegations is in part why I surmised that this appears to be a pretty minor injury.

I've got a few road rash scars, none of them have caused me to miss work, limited my ability to earn income, cost me any medical bills, or motivated me to seek reconstructive surgery.

Polaris OBark

The screen-shot I posted shows that Jan says the sidewalls clearly make a large difference, with the Endurance version being more tolerant to higher pressures before blowing off.

I also wonder if the very thin sidewalls might contribute to roll-off. I often see those cross-hatched markings on my sidewalls which I only recently learned is a symptom of having too little air in the tires, causing the sidewall to collapse on cornering, especially on-road.

tomato coupe

I gotta say, if I was on a jury for this lawsuit, I wouldn't be too impressed with JH's response to a pretty simple compatibility question. He seems to be implying that the wheels don't meet current standards and, therefore, they can't recommend it. But, because the tires offer a larger margin of safety, he also seems to imply that they'll be okay.

chaadster

I understand what Heine said as not necessarily being the same thing which you said, i.e. a stiffer casing being more suitable for higher pressure (on hooked, hookless, both…the context was unclear) is not necessarily saying the casing inhibits bead stretch. The stiff casing may resist bead movement, but all movement is not stretch, so I just wonder what that relationship is like.

Regarding the cross-hatching, which I thought was the casing weave showing through, I’ve had that with some tires, but I never run underinflated to the point where the sidewall collapses, so I’d question that manifestation as an accurate diagnosis of underinflation. I’m not certain, of course, just having a hard time relating it to my experience. In particular, old Conti GPs used to show that a lot back in the day, when, if anything, we all ran overinflated!

Koyote

If you were running those tires tubeless, that was too much psi.

Sounds like your problem was user error.

Sy Reene

IMO, the problem is that going hookless for a tandem setup was the wrong choice in the first place, at least with rims that wide. I'm guessing somewhere like a minimum requirement to hold 250+ lbs of rider weight is needed and I don't think the use case here would likely ever work if we're talking about a road setup. EDIT: I take that back, perhaps the max rating of 55psi would have been just fine, that is if the rim/spoke combo themselves are rated to hold whatever system weight we're talking about here.

GhostRider62

ran hearse/compass tires a lot, they are not very tight out of the box and loosen up a LOT with use. It ain't rocket surgery

Chilepines

My point in posting about the blowout was to let people know that it happened. I was not blaming Specialized or Light Bicycle, so yes it was user error. Maybe I should not have gone hookless for the tandem, so there may be a set of very lightly used LB rims for sale soon.
Having said that, 65 psi is not crazy high and I'm sure someone else out there is running a similar setup that might blowout on the front wheel on a descent. Sharing information on here ought to be the point.

phrantic09

I think it’s a Panaracer thing. I’ve got a set of Gravelkings that are so loose I can pull both beads up and off of my Zipps at the same time. Meanwhile other road tires are much tighter and tougher (but still easy) to get on.

chaadster

Looser/better/tighter/harder clincher rim/tire combos have been a thing since the clincher, or at least since I started working on bikes in the ‘80s. Tubeless designs might have exacerbated the commonality of the issue, but the issue has always been with us insofar as I can tell.