surak

I found this SlowTwitch article from 2023 between Dan Empfield and Josh Poertner on hookless safety to be quite illuminating, and it avoids the drama/emotions drummed up from the high profile blowouts in the news that spurred the current focus on hookless.

It's balanced in the sense that neither are arguing for a ban on hookless and agreed that it was the direction wheels were going to go, but they disagreed on how dangerous current hookless wheels were to use for road cycling. Two things Josh said jumped out to me: 1) no measurable performance benefit to hookless, and 2) an alarming rate of blowoffs in testing hookless rims vs. none with hooked.

Also Adam Hansen, CPA head, wrote in the comments of an Escape Collective article

79pmooney

[QUOTE=surak;23177690]I found this SlowTwitch article from 2023 between Dan Empfield and Josh Poertner on hookless safety to be quite illuminating, and it avoids the drama/emotions drummed up from the high profile blowouts in the news that spurred the current focus on hookless.

It's balanced in the sense that neither are arguing for a ban on hookless and agreed that it was the direction wheels were going to go, but they disagreed on how dangerous current hookless wheels were to use for road cycling. Two things Josh said jumped out to me: 1) no measurable performance benefit to hookless, and 2) an alarming rate of blowoffs in testing hookless rims vs. none with hooked.

Suggesting Thomas de Gendt isn't totally out of his head.

Trakhak

If I'm reading correctly, you're not so much saying that there's an advantage to hookless as that there's no disadvantage.

On the other hand, I have read suggestions that the walls of hookless rims have to be stronger to keep from flexing outward from tire pressure - otherwise, the chance of a tire blowing off would escalate - and are therefore, as a fortunate coincidence, also less prone to being damaged by potholes and such.

tomato coupe

Okay. But, you certainly didn't address it.

Sy Reene

So you've had a number of major punctures on hookless doing this and it was just fine?

Atlas Shrugged

I live in a mountainous area with a strong cycling community. On an average weekend on our local climb which is approx 3000’ there are hundreds of riders most on premium gear of which I am sure some are hookless. Also one of my best friends owns a local premium bike shop who moves hundreds of quality bikes a month some of which run hookless. I have never heard of an issue the death cult seems so obsessed about.

Sy Reene

I don't doubt it, but how many have had major punctures while doing the downhills at 50mph?

Koyote

You’re implying the number is very low — which supports the conclusion that the scenario isn’t worth worrying about.

Yan 

Exactly!

elcruxio

The advantages of hookless are purely in the manufacturing side. There are no advantages for the rider in terms of riding. I won't address the price thing because there has been a good amount of discussion on that already.

There are however disadvantages for hookless in terms of riding and use.
they aren't as safe as hooked.
This one's pretty self explanatory when you think about it. The tire and rim width combinations are extremely limited when compared to hooked. With hookless you have one rim doing one job, because there's so few tire widths you can use on a given rim width. With hooked you can use a narrow road tire and a wide gravel tire on the same rim.

The pressure limits are low. The tires can't hold on for more pressure, which isn't confidence inspiring.

Tire choices are limited, because manufacturers need to test whether a tire is safe on their rim. Which is absurd. Standardization should be enough.

ETRTO is enough for hooked. Hookless is based on ETRTO but that's a wrong standard, because ETRTO was made for hooked with the assumption there would be a hook. Taking the hook away makes the rims pretty darn different.

In order to make hookless safe there needs to be tighter tire manufacturing tolerances, which just isn't going to happen. Bicycle tolerances are what they are and have always been. To assume they're magically going to get better is silly.

To address the tolerance issue AND the blowout issue, sidewalls of hookless rims need to be taller. But this in turn can make mounting tires nearly impossible on the road. Having floppy 200g tires on rims which have had THE major tire retention device removed is just asking for trouble.

I remembered correctly btw. There was a manufacturer that proposed glueing on a hook after the rim has initially been manufactured with the hookless process. That manufacturer was no other than SRAM.
That might actually be a pretty good idea, because you'll get the advantages of hookless manufacturing and a bead hook. So to have your cake and eat it too.

Sy Reene

To your points above, it seems that many of the issues relate to the very wide rim widths being made hookless but for road riding (ie. 25mm ID widths). All of this for the supposed aero benefit.
From the below, a hookless rim with a 19mm ID width is supposedly compatible with every road tire width you'd probably ever want to be able to run, and supposedly, a 19mm rim width allows higher pressures than the 73psi bandied about all of the time.

eduskator

Yeah, the word ''extremely'' in his post is a little extreme (see what I did there?).

msu2001la

The hooks only work when the tire is inflated. A deflated clincher on a hooked rim is still going to come off if you keep riding it.

You either believe that DeGent's tire spontaneously blew off the rim, causing the crash (and rim damage occurred during the crash) - or you believe what Vittoria and Zipp have concluded, that he hit a rock, which damaged the rim causing the tire to deflate, which then came off the rim.

On either system, you're probably in a world of trouble if you have a spontaneous blowout at 50mph on an alpine descent. Pretending that hooked rims are going to save you in this situation is silly.

eduskator

Yeah, lets wait to see the conclusion of the investigation. I would not 100% rely on the manufacturer's statement given that they are in a conflict of interest, but for what it's worth I think that hookless rims are safe.

People skip to conclusion too fast nowadays.

seypat

Can we get some decent, zoomed in footage of the wreck? I'm not seeing the sudden, violent deceleration from hitting an immovable object hard enough to break a supposedly strong sidewall rim. I don't need to see an endo, but he just looks like he lost traction in some loose surface covering. It doesn't look like he hit a trip wire, curb or expansion joint sticking up slightly. We need to see the rock big enough to cause that damage.

elcruxio

If you look at rim manufacturer websites the allowable tire widths are far more restricted.

As to the 5 bar / 73psi, that comes directly from ETRTO. So essentially the absolute do not exceed limit of hookless on any size tire is 5 bar / 73psi or lower if dictated by the manufacturer.

I'd love to get the current ERTRO standards handbook but it's 150 €, so a bit too steep just for wanting to know a few things.

eduskator

False. I had a pair of hookless Giant SLR-1 wheels on my previous race bike and they had a maximum pressure limit way above 73psi. It was 125psi if I recall properly. Most manufacturer, however, have a maximum pressure of 5 bars.

Giant Hookless Technology | Giant Bicycles Canada (giant-bicycles.com)

elcruxio

You may want to review the content behind that link. Like I mentioned earlier, the 5bar / 73psi is set by ERTRO, meaning that rims / tires deviating from that would be outside the specifications set out by ERTRO.

phrantic09

You guys convinced me!! I’m selling my Zipps tomorrow and buying a set of hooked alloy DT Alexrims wheels that weigh 2200g. I mean between no hooks and possible crabon asplosions i definitely should ditch these wheels.

mstateglfr 

Over the top responses that go to the extreme and dip into the absurd are always fun to read.**

phrantic09

Well, I guess since it was supposed to be as absurd as some of the responses we’ve seen in this thread, mission accomplished.

Sy Reene

From digging around, the 73psi guidance is for a very specific subset evidently (namely tires labelled as 25-29mm). And then using the 'because physics' logic, well maybe you can interpolate that if 73psi is max for 29mm tires, it should really be higher for a 25mm tire because there will be less volume of compressed air . And as you get more away from the sweet spot for tire vs rim width compatibility, the PSIs should change for those reasons as well.

mstateglfr 

genejockey 

As entertaining as all this is, it's all moot for me because I can't justify (to myself) spending that much on wheels, so I'm stuck with hooked alloy rims.

DaveSSS 

I agree with the poster who said that a major puncture at 50 mph is going to be a big problem with hooked or hookless rims. I go that fast dozens of times each year. I'm not going to worry about it, but I do watch well ahead for possible road problems.

Whoever said that hookless rims make for limited tire choices is correct. The most popular tire widths have been increasing as disc brake frames have gradually replaced rim brake frames. Along with disc brakes has come wider tires. 25mm is now considered to be on the skinny side and very few are listed as compatible with hookless rims. 28mm tires have become the new minimum, like it or not. Hookless rims also work with much wider gravel tires, so they don't restrict gravel tire size. If you move up to the 25mm IW hookless rims that I use, most tire brands approve of 28mm and larger tires to be used on them, but ETRTO has recently decided that 29mm is the new minimum. In 2022, 28mm was OK. I've had no problems with 28mm and I'll at least use them until all of mine are worn out. I've got six 30mm Pirelli P-Zero Road TLR tires that are significantly less expensive than race version, waiting to be used.

Those complaining that they can't use hookless without exceeding 73 psi are probably restricted by a frame that can't handle a tire larger than a 28mm and/or you're not using the Zipp pressure calculator. The Silca pressure calculator does not consider internal rim width or hookless rims and limits the combined rider and bike weight to 200 pounds with 73 psi. The Zipp pressure calculator allows a total weight of up to 270 pounds with 28mm tires and 23mm IW hookless or 21mm or wider hooked tubeless rims, at higher pressures. I use the Zipp pressure calculator exclusively.