Rim tolerance and pressure.
Eventually standards will tighten up and hookless (like disc) will be universal imo.
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Maybe Iām not phrasing my question properly.
When I say what scenarioā¦Iām talking about movement of tire bead relative to the rim.
If the bead of the tire is loose enough to be able to lift off the rim shelf and shift aroundā¦how is it going to still be airtight in the scenarioā¦and further how would the little hook sugnificantly contribute to this when there is space between the bead and rim shelf? It seems like the hook should never be exerting any force on the bead if things are set up right.
It just seens to me if your setup allows the bead to lift off the rim shelfā¦itās not going to work well under any circumstancesā¦
I guess at best, I see hooks as a sort of parachute. Sure I guess additional insurance is good, but your plane is already crashing if you need itā¦
Giant SLR2 with GP5k STR 28mm here running flawlessly. Combination carefully checked on Giantās material before mounting (approved). Interesting though, Pirelliās TLR arenāt recommended (approved). BTW, the list of compatibilities is pretty narrow, which wasnāt a problem for me as Iām intending to use GP5K anyway.
I have no issues with new technologies, if they say it works and they tested, here Iām to ride.
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You are only looking at one side of the equationā¦.the other side is the tire bead. It is a different bead for hooked rims. It works as a system and the overlapping nature of the system provides a more secure fit.
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Yes. Also, the pressure in the tire is passing the tire up and away from the rim. The part of the tire in contact with the ground is getting pushed back towards the rim, but the other 95% of the tire isnāt.
With hookless, that force is trying to dismount the tire. Thatās why hookless rims require lower max pressures. On hookless additional pressure is more force overcoming friction between the rim and tire, which causes the bead to move.
With hooks, the force is locking the two hooks together. On hooked rims, max tire pressure is only limited by the strength of the materials. Itās the shape and strength of the hooks (tire and rim) that keep the system safe.
With either hooked or hookless, tubes vs tubeless is another factor. Tubes are another force resisting the movement of the tire relative to the rim. It adds more friction and and fills in the little gap between the tire bead bottom and rim. So the tire canāt move up and over the room wall as easily as with tubeless. Thatās why with tubeless you need such a tight fit between rim outer diameter and tire bead inner diameter.
However, weāre talking about 2.1 meters (7 feet) of rubber circumference and rubber inherently stretches. (Even your Kevlar bead is coated in rubber). Also, manufacturing tolerances off larger diameter inherently are larger, for both rim and tire. And tires vary a lot, just look how the weight of the same tire can vary by +/-10% even on a road tire with minimal tread.
Material strength and shape are a lot more predictable and consistent than friction coefficients and tolerances on a large diameter, especially with stretchy rubber involved. Therefore, hooked, tubed setups have inherently more consistent capability and hookless and tubeless are inherently less consistent and therefore less safe.
Can hookless and tubeless on the road be done well enough? Sure. Would I trust anything out there right now, given the engineering and quality control status of the bike industry combined with the relative immaturity of this technology? Thatās a hell no for me. Even major players like Continental are struggling with it. (Not just this incident. Look at all the issues with their original GP5k tubeless).
This particular failure might have been defective parts or user error (using a setup with not enough of a tight fit). However, if thereās that little safety margin, itās not safe enough IMO for a consumer product. Especially once that a significant percentage of consumers replace themselves.
Just the fact that you have to fine tune the rim diameter to match the tire (by layering on extra layers of tape until it fits real tight or buying and returning or reselling tires until you find a good combo) is utterly ridiculous and way too errors prone for consumers and even bike shops. How tight is tight enough? Will it stay that tight as the tire breaks in? How much safety factor do you have? WTF kind of engineering solution is this for a safety critical issue?
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Exactly.
I have hookless rims and didnāt have to do any of this, the below scenario is not what the majority of users are experiencing in 2023, or frankly 2022 which was when mine was purchased and setup.
With certain combinations of models it is necessary. Or if you bought 100 wheels you might have needed to do that on a significant percentage of them. Either way, thereās plenty of reports of bad fits, including earlier in this thread.
Also if you read the manual for these rims, it explicitly says this. But I think other manufacturers are saying the same. Users certainly are for many models.
And imagine if you bought a car and found out that only a few certain models of tires will not suddenly fail on you (regardless of being the same size and speed rating). And even approved tires might fail on you and thereās lots of reports of that happening. Thereād be lawsuits and recalls if it was automotive, but the bike industry gets away with it.
Anecdotes, like āmy hookless wheelsā are problem free are meaningless. Having a tire blow off a rim is not acceptable even if itās a 1 in 10,000 occurrence.
The risk of ending up with an out of spec tire, a stretched tire, or an out of spec rim just doesnāt seem worth it. What is the consumer getting for this risk?
(BTW, every one of my Continental TR tubeless tires as stretched after being installed for a while. Cars have hookless rims but they also have steel wire beads which will not stretch.)
The ability to buy Zipp wheels for $1000 and Enve wheels for $1500? There are tons of other wheels with hooks in that price range. So far, this is the only benefit Iāve seen posted about hookless.
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Easily as useful as anecdotes like āI overinflated my tires above the limit set by the manufacturer and used tires that arenāt listed as compatibleā.
No one is forcing you to buy hookless, and if the problems are as bad as you think they are then you wonāt have to worry about it because manufacturers are not going to want to open themselves up to lawsuits.
Give me the hooks, Iāll spend an extra 50 grams and 50 dollars on them.
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That is a brilliant argument. We are discussing a new technology that has entered into road cycling. Itās good to know pluses and minuses before buying. And yes, based on the current evidence, I wonāt buy hookless.
I really havenāt heard any pluses on this tech other than āmy wheels have been fineā. Thatās not good enough as I expect failures to be low.
I was tempted by the Zipp 303s a few weeks ago but there are tons of other wheels in that price range with hooks.
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The reality is that there is no data on this issueā¦.the only thing we have is anecdotes.
There are a lot of questions about the video linked aboveā¦.quality if the rims, was the bead damaged during installation, etc. Honestly, while I made a joke about the guy running this experiment in his kitchen, it gives me pause as to his setup and if the tires were installed correctly.
I am not defending hooklessā¦.I have no plans to buy hookless or ride hookless on the road anytime soon. But there is also a lot of hand-wringing over what appears to be very few incidents (with unknown causes, honestly).
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I still am basing my thoughts on this on the fact that when I push my tire off the edge of the hook on my rim, it still is airtight. I just dont think the hook is where the air seal is on a properly set up system.
I think it sits there as functionally an appendix, until POSSIBLY acting as insurance to keep a flat tire from coming off the rim.
At first I was like 
Then I was like 
Now the original video has been set to private Iām like 
Iām also shocked that both hookless AND Lizzo have been cancelled in the same week! What are the chances of that?! Damn it Internet.
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Iām not surprised. The guy runs cycle tours on Majorca. People have been accusing him of staging or faking the video to generate clicks. Other youtubers did videos about his video showing him where he was so wrong. I sincerely believe he simply showed what was happening with his wheel and tire combo.
Why are so many consumers so defensive of hookless? Nobody can explain to me why I should buy hookless over hooked if Iām looking at two similar wheelsets.
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Itās just another debate that canāt be answered in black or white, so it becomes Internet attention fuel.
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The same reason so many people are critical of it.
When youāve considered the risks, reviewed the products, and made an informed decision on technology, itās a little annoying to hear people dismiss it without adequate (if any) evidence.
People were defensive of disc brakes when they first pleaded, too, and critics were assuring us weād be cut to bits of melt our spokes.
Bb
You make it sound like one shouldnāt be critical of a new technology where a tire can blow off a rim at a pressure that was previously thought of as a normal road pressure on the lower side (72psi) . It doesnāt matter to me whether it happens 1 in 1,000 or 1 in 10,000.
Not from a safety point of view. They were already a proven technology.
There were a couple of incidents in pro racing or riders getting cut in crashes and, guess what, the industry responded and rounded the edges of rotors.
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Noting yet again, there are a host of variables we know nothing about in the video that started this thread. There is a reason we prefer to get our science from labs and tests and not from youtube videos.