Nice video.

Hooked rims are a thing of beauty, and proven by years upon years of use.

The only tangible benefit that come from hookless is a lowering of assembly cost by removing the need for tooling that wears out to make the hook. The industry is trying to solve the issue of hookless by making sure that the tolerances are tight, tires don't stretch, and specs are set with some wiggle room.

It turns out that keeping control over all these tolerances is tough. In this case, running slightly under ETRTO makes for a catastrophic failure. The way and pressure this tire blew off would make me question even at ETRTO spec, would the tire stay on?

However, with a hooked rim, you don't care because hooks allow a tremendous variation of tolerances to specifications without failure.

Time will tell if specs and tolerances can be selected and controlled enough to allow hookless to go into all bicycle applications, but it certainly seems like this is not a technology that you want to be aggressively using if you are not forced to use it.

I personal hate that putting on a Conti GP5000 has turned into a 4 minute ordeal of coaxing, making sure the bead is in the center of the rim, and watching my tire iron almost break every time as I pray the tube is not pinched.

More ideal would be somebody smart figures out how to put on a cost effective hook. Peak Torque recently talked about SRAM's new patent to do just this.

Just fwiw, Extralight has some really explicit taping instructions for those rims, and there's little to no mention of this in the vid other than "taped by expert". From what little is visible in the video, it sure looks like the tape is a bit narrow for that rim, and he never mentions checking either the width of the tape or that the thickness meets the total of .3mm required by the manufacturer. Judging by the fact that they mention the tape requirements at least 1/2 dozen times in the one page tech sheet for the wheels (with big yellow warning graphics) they think this is pretty important, so it strikes me as odd that it's not really considered in the vid.
That's a lot of tape, by the way. It's three full wraps of something like Tesa 4298. I haven't measured the Schwalbe tape, but I would imagine you aren't going to hit that thickness requirement with the one wrap of tape that Schwalbe says to use in their own installation docs.

That big Topeak charger pump in the video is also worth noting. Extralight explicitly warns of damage if more than 5 bar was used in initial beading of tires, and if he used that thing it absolutely was. Reading between the lines, using a charger pump or compressor on these wheels will actually void your warranty, which is pretty unusual.

It's definitely a problem that you need to dot all the "I's" and cross all the "t's" with some (or a lot) of the tubeless stuff out there these days, but you do still have to, especially with the more exotic offerings like these Extralight wheels, which... I mean, the name kinda says it all, doesn't it?

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Tech writer/support on this here site. FIST school instructor and certified bike fitter. Formerly at Diamondback Bikes, LeMond Fitness, FSA, TiCycles, etc.
Coaching and bike fit - http://source-e.net/ Cyclocross blog - https://crosssports.net/ BJJ instruction - https://ballardbjj.com/

Well I'm not an absolute expert, and the video maker probably neither, but he did not make a blatant error. The only things (reading the posts above) could be the 1mm outside of the ERTRO specification or an alleged incorrect application of tape.
It certainly would not bias me to buying a hookless rim when I would move to tubeless at all ( I still use clinchers).

If you are using tubes on a hookless rim, you are doing something wrong!

I don't think it is in any way possible after reading the manufacturer's tech sheet for this product to characterize (potentially!) incorrect application of tape as anything other than a blatant error. The manufacturer makes clear just how important it is to tape the tires correctly.

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Tech writer/support on this here site. FIST school instructor and certified bike fitter. Formerly at Diamondback Bikes, LeMond Fitness, FSA, TiCycles, etc.
Coaching and bike fit - http://source-e.net/ Cyclocross blog - https://crosssports.net/ BJJ instruction - https://ballardbjj.com/

I do not deny you're right about the thickness of the tape and that the warnings are plenty in the manual of the rims. It is debatable though whether you can expect from a "normal user" to measure thicknesses of < 0.3 mm.

"normal" users shouldn't be on something like a 1080 gram Extralight wheelset. If you choose to run something like this, you need to get stuff like this right. The margin for error went out the window along with those couple of hundred grams.

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Tech writer/support on this here site. FIST school instructor and certified bike fitter. Formerly at Diamondback Bikes, LeMond Fitness, FSA, TiCycles, etc.
Coaching and bike fit - http://source-e.net/ Cyclocross blog - https://crosssports.net/ BJJ instruction - https://ballardbjj.com/

Interesting comments. I had no idea.

Even more reason not to choose those rims if they come with instructions and dire warnings like you’ve just adopted some Gremlins.

I mean it’s clearly common practice to use compressors or charger pumps to seat tubeless tyres. And pretty tough to get your rim tape that accurate. I reckon I’ll buy from the wheel brands that have to idiot proof their products.

That's a real problem with videos like this. Niche weight weenie products aren't representative of much of anything other than themselves, and problems people may have with them certainly shouldn't be seen as an indictment of an entire product category, much less the more "normal" products (in this case, tires) that are sometimes tortured into failure by the exotica they're attached to.
In this case, despite not meeting the etrto guidelines, Extralight claims the conti tires will work on these wheels if you follow their directions. The video glosses over essentially all those guidelines and directions, and then seems to largely blame the tire manufacturer.
I'm definitely not one to claim there aren't problems still to be resolved with tubeless bike tires, generally, but this ain't on them.

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Tech writer/support on this here site. FIST school instructor and certified bike fitter. Formerly at Diamondback Bikes, LeMond Fitness, FSA, TiCycles, etc.
Coaching and bike fit - http://source-e.net/ Cyclocross blog - https://crosssports.net/ BJJ instruction - https://ballardbjj.com/

That's the conclusion I was waiting for.

Problem for "Extralight": I would not trust an average LBS to mount a tire on those rims. And when finalky an expert, who knows what he's doing (far from being a "normal" LBS), has mounted the set, who's gonna ride it? A "normal user"? Is he allowed to pump it up, put new milk in it?

A rim which can only be set up by experts and driven by it: great business idea.

Hookless rims - a solution without a problem. And a potentially dangerous one at that. Hookless rims are all about reducing production costs and expanding profit margins, and not about speed.

Some interesting information in this video about hookless - and an SRAM patent to bond hooks onto hookless rims. Generally some interesting other stuff as well. From about 5 mins in.

https://www.youtube.com/watch?v=YJc3DVVcTuM

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He who understands the WHY, will understand the HOW.

Yup.
People rightfully don't expect that they can buy an F1 car and fill the tank at the corner gas station, but...

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Tech writer/support on this here site. FIST school instructor and certified bike fitter. Formerly at Diamondback Bikes, LeMond Fitness, FSA, TiCycles, etc.
Coaching and bike fit - http://source-e.net/ Cyclocross blog - https://crosssports.net/ BJJ instruction - https://ballardbjj.com/

Aerodynamics and rim "toughness" are arguably tangible benefits. I haven't seen the hard data, but the arguments explaining how hookless could provide those benefits seems quite plausible to me. Maybe the're very marginal benefits, but could be benefits nontheless.

I'm an self-admitted tubless newbie, but how does thin tape contribute to poor tire retention? Air retention...I get it, but not tire bead to rim interface. I could see too thick tape or too-wide or off-center tape, but not too thin or narrow.

Or is there supposed to be tape between the rim and tire? I had always assumed it was tire to rim and not tire to tape to rim.

May I ask why thickness of tape makes a difference in this context? Why does 'Extralight' specify tape (?multiple layers of) of that thickness (>0.3mm)? Do some other hookless rims also require 'thick' tape?

I'm not an expert, but my understanding is that tape changes the the effective bead seat diamater, which is a critical thing in tubeless. Too much tape and it's too tight, too little and the bead isn't placed under the proper tension. Enve doesn't have nearly the same repetitive warnings that Extralite has, but does recommend using only their tape. I checked Zipp, and their instructions are more just like generic tubeless rim taping.

Though in general hookless may have made manufacturing easier, but it does seem to have offloaded more requirements on users (us). And the narrow range of acceptable tolerances between rim, tape, and tire is a bit concerning.

I'm reading that "semi hookless" is now a thing, maybe to expand that range a bit.

Seems like this could be claimed 'foreseeable misuse' against the manufacturer.

Interesting. I had always assumed tape was to just cover the spoke holes and not to help the tire to rim interface sealing. Reading some more, it tubeless tape should go up the sidewall of the rim by 1 to 2 mm.

That does beg the question if tape is needed for tire retention or just holding air.

Back to the OP, since 25mm typically recommend pressures at or above the hookless limit of 5 bar/72psi, 25mm tires seem like a really poor choice to set up tubeless anyway. 28mm seems like the minimum, if not 30mm.

I am still using hooked rims, so no anecdotal info from me. But you need to be a total nutjob to purposefully blow a tire full of sealant in the middle of your kitchen/living room, right?

Ha. That's why I have trouble taking the thing seriously, as it was clearly staged for maximum clicks on YouTube. I'm a little surprised there wasn't an 8K video slow-mo of the sealant blowing all over his pristine kitchen.

In all my years cycling ( a lot!), this is the first time I've seen a movement towards a less safe technology. The argument that it works for car tires is a poor one - car tires and bicycle tires are very different. What the heck is going on?

Tubeless rims that are designed to be taped need to account for the thickness of the tape as part of the rim bed, and so they're typically underdimensioned prior to the tape being applied.
The problem here is the non-snug fit of the bead on the bead seat shelf. If a tire bead creeps downward and/or inward on one part of a rim, it gives the bead slack to creep upward elsewhere.

In theory you can manufacture hookless rims thinner or stronger with their more uniform shape. Great news for those hoping for better carbon fiber rim brake wheels, which means people who are adopting tubeless/hookless tech but unwilling to adopt disc brakes (a vanishingly small subset). For disc brake wheels the rim strength is already constrained by the 'holding up the weight of the bicycle and rider' need and can't get much thinner/lighter. See carbon tubular disc brake rims as an example of how thin they can possibly get.

(and for the 'car tire' argument, you need a hydraulic press to mount/dismount a car tire. The forces aren't even the same order of magnitude)