I have a question.
What was there first when designing hookless wheels.
The design and they, the manufacturers, found that the limit a tire stayed on safely was 5 bar max.
Or was the limit 5 bar rule already there and the design based on this existing rule of 5 bar?

I mean, is it technically not possible to create a hookless wheel that can hold a tire on at, lets say, 6 bar?
Why was it set on 5 bar at some point? Was this the result of testing after the design was finished and they found it couldn’t hold a tire safely beyond that pressure.
And started calculating optimal pressure to weight with that as a starting point?

Jeroen

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Owner at TRIPRO, The Netherlands

I'm guessing the process was "we can manufacture wheels quicker and cheaper by eliminating the hook". And then they probably determined 5 bar was the safe max PSI. Zipp and Enve seem all in on hookless, and it does seem like the "technology" is safer at lower pressure's, which wider tires will allow.

There are some ways you could increase the pressure but they all have trade offs, mostly about mounting the tire. A tire bead with less stretch would be one way to do that. You could also increase the actual diameter or the wheel, specifically the edge of the rim, or decrease the diameter of the bead. A potential way around this is to increase the diameter of the rim and increase the depth of the rim channel, which would give more slack for mounting. You can only go so far with this until the rim edge/tire interface is happening up the sidewall at a section of rubber not designed for that.

There's also the added complication that the tire and rim manufacturers are usually different, so the margin for error needs to be greater. In theory if Zipp made hookless rims only for specific Zipp (or similarly known QC controlled) tires then the error margin could be lessened.

My guess is that a limitation of design was the ability to mount by hand, or at least with common plastic tire levers. That will fundamentally limit the psi unless there is something positively engaging the tire to provide extra holding force. Aka a hooked rim.

I've been avoiding tubeless (and disk brakes) because I just didn't didn't want the hassles. I was quite content with my HED wheels and 25mm tires with latex. But that all changed when I rode a bike with ENVE's latest 3.4 wheels and 28mm tubeless tires at 60 PSI. No loss of speed and a limo-like ride.

I bought a new road bike almost on the spot because of how good the system felt.

My triathlon bike is a Felt IA with rim brakes and latex tubes. To make a meaningful upgrade, I would have to jump to a modern TT bike with disc brakes. I am not there yet, but I cannot deny the dramatically superior ride I would get with 28mm tubeless on the latest carbon wheels.

1. One thing is what the industry offers to buy and the other thing is what people ride nowadays. There’ll always be a lag of a couple of years, simply due to limited riders’ budgets (there’re other reasons like buyers’ hesitation / negative sentiment, that you seem to exaggerate). If only any new beautiful disc wasn’t costing us over 2’000 USD…

2. Preferred wheel and tire choice for road cycling isn’t the same as for triathlon nor TT. Triathlons & TTs are faster, often non-drafting and usually on better closed roads chosen specifically for a race. This makes the aerodynamic properties more important than rolling resistance, even more than in the same comparison for road cycling. Your preferred tire width for road bike might be 28/28 or 30/30 nowadays, but it’s probably 25/28 for a triathlon bike. Most triathlons are on the roads, so I don’t think 25mm is entirely dead, as it’s the most aerodynamic choice for 19-21 inner width wheel.

3. Would you care to share some bike count data from the last Kona and/or Nice? Or at least the pro bikes, please. We would clearly see how few of those pro riders rode anything more than 25mm in the front.

I am no Marcag, but I think most of us already agree that 28mm is the sweet spot for the rear tire - my issue is the front wheel on a Tri, or even more specifically, a TT bike.

For example, the GCN video comparing tire width vs speed that concluded there is statistically no difference, but they had a max speed of 23.6mph - pretty slow even by my 77 year old standards. "https://www.youtube.com/watch?v=AK5KLvrzrb4"

Again, I remain unconvinced for the front wheel.

"Road" is a wide range of terrain. Consider IM New Zealand's rough chipseal, versus some other courses with smooth asphalt. There are plenty of courses where I'd happily go with the wider / lower pressure tires.

Yeah, I resisted for a long time. Until I tried 30mm tires on my road bike in my mountain-y terrain. The difference is not subtle.

It's a problem for me. I used to spend around 50% of my time on my TT bike - which benefited me immensely when racing other roadies in TT. I could beat people with superior physiology simply by being trained for the TT position.

Now when I walk into my garage for a "TT bike day" I often cringe inwardly looking at the 23mm tires, and then grab my road bike instead.

I make up the difference by spending 100% of my Zwift time in the TT extensions.

It seems that Zipp is saying that a glass smooth wood floor is the cut-off between hooked and hookless with respect to optimal presure for the majority of riders. At this point, that is a very helpful exclusion - for them.

Almost an indoor / outdoor “determination” by Zipp.

However, outdoor testing shows a whole lot of conditions (road surfaces) where pressures over 5 bar is faster. As the article points out most TT and triathlons are held on normal road surfaces as opposed to chipseal or cobbles.

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Dan Kennison

facebook: @triPremierBike
http://www.PremierBike.com
http://www.PositionOneSports.com

I think it is JP Ballard of SwissSide who likes to remind people that the Laws of Physics haven’t changed. So you can’t ignore the A in CdA. Now it would take a real aerodynamicist to tell you if widening the entire tire/wheel system can change the overall shape in a way that Cd is reduced and if that change can offset the 12% increase in A of going from a 25 to a 28.

As mentioned before, reliable test data finds real world situations where the fastest pressures exceed the 5 bar limit, so I think it is incumbent on companies like Zipp to demonstrate that their pressure calculations are correct and that Silca, SwissSide, Marc Graveline, Premier, AeroCoach,… are wrong (as an example, Marc found that Sylvan Adams was fastest on a 23mm front tire during their testing for Master’s Worlds).

I think the real solution to the hookless issue is to reduce the stretch in the tire bead. If hookless tires stayed on at 7 bar there would be no debate that it was the way to go. Maybe we will see wire beads come back in style.

In a previous Post I had suggested (tongue in cheek) that they should use a titanium wire bead, and eliminate the pressure issue.

Quote Ronan McLaughlin @ Escape Collective - "The dimensional conversation highlights one inherent design challenge with hookless road systems. For all the talk of the missing hook, rarely mentioned is the dimensional and customer-expectation hurdles manufacturers must scale in producing hookless road system that is both safe and easy to use from a tyre installation standpoint.


One could argue a truly safe hookless road system should consist of a steel-bead, stiff-walled, non-folding tyre. That tyre should be mounted on a rim with a BSD, flange height, and rim well depth all exactly to standard.

The only issue with such a system is that it would prove all but impossible to install a tyre at home, let alone do any roadside repair that required more than a plug, some sealant, and air. The claimed and debated benefits of hookless road system may exist, but if they do, they do not come for free. The cost is either a thumb-busting process for changing tyres, or a system that allows for easier tyre mounting but is perhaps more prone to tyre dismounts." unquote

...and since moving away from tubular tires, when was the last time you had to change the whole tire while out on the road?

We are in agreement.

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Dan Kennison

facebook: @triPremierBike
http://www.PremierBike.com
http://www.PositionOneSports.com

X2!

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Kiwami Racing Team

Are there issues with pressure for hookless and mid-race flats? Seems like they have a fairly narrow pressure window (high enough to ride, low enough to not have blowoff risk), and inflating with a CO2 isn't exactly science.

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ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)

Is the rim brake track still in tact on the new super 9 like it was on the older version even for the disc brake version? It’s had to discern from the pictures.

I think this version is a little more expensive than its predecessor. Maybe $100-200 more.

Is there any aero data that can show the delta between the older (25mm optimized) vs newer (28mm optimized)?

Edit: Is this the first hookless disc? I’m a little surprised zipp came out with one before enve.

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blog

I’m far more offended by the $3,000 price tag than hookless. 😁

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Favorite Gear: Dimond | Cadex | Desoto Sport | Hoka One One

i think what you might find in the future is that max pressures for hookless will scale with tire size. the 5 bar max was pretty arbitrary. i think that'll get tuned. however, what i think you're likely to find is that 5 bar for tires 28c and larger is plenty enough for almost all people in almost all use cases.

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Dan Empfield
aka Slowman

i will share any data i have. i wasn't in kona or nice last year; i think i might be able to help get tire size counted. just, it's hard to count. you have to almost just ask those taking their bikes in what tires they're riding. or, if it's just the pros ask them prior to or after their races via some other contact method.

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Dan Empfield
aka Slowman

i'm not convinced of this. if you're talking about 28c and up. i don't think we've yet had that much testing on a 28c tire for TT applications. for Crr, that 28c tire in, for example, silca's calculator swells to 30mm when you put it on a hookless road wheel, because those wheels have such wide bead widths and silca specifies measured width. you have to get to a very smooth road before you exceed 5 bar on a 30mm measured wheel. and that's silca, which is going to yield higher pressures than what the manufacturers say their pro teams are using. i think this is one of those areas where we must agree to disagree pending some moment where those testing generate more agreement in their results.

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Dan Empfield
aka Slowman

I am no marketing guru - but why the heck did they not give it a new name. Now, trying to buy this online, people will struggle to figure out if this is the new or the old Super 9. Shoudda called it Sub-8 :)

I find it interesting that with NO DATA, we are claiming what is better/faster........and "I told you so".

"i don't think we've yet had that much testing on a 28c tire for TT applications", yet we're talking about a $3000 disc wheel for Tri and $2000 NSW wheels for Tri. Are we not ?

"pending some moment where those testing generate more agreement". If nobody shows their data, we will never get agreement. We have no data.

I have not seen any data on roads that resemble those used for TT and Tri. I have asked, nothing, nada.

I cannot release all my data. It belongs to the teams and the athletes and I know the team will not release it and I don't plan to ask the athletes. I can gladly talk about protocols to feel comfortable they make somewhat sense.

What I can release are "aggregated" results: very simply a 28mm tire (size on label), on a hookless rim, on a typical AGer, on a good bike path has an optimal tire pressure above 5 bar. This according to my results, which could be completely flawed. I don't pretend to have "the answer". But I do think what I am finding needs to be confirmed. I have also spoken to WT guys and they go "ya, that makes sense".

Speaking of WT experience, yesterday at breakfast a bunch of mechanics at the hotel were sharing their stories on hookless, tire recalls, disc brake specs, how they see things at 1000x the speed consumers do. That is worth an article all by itself.

I have quantified it for several riders, it's in single digit watts, but it's waaaaay more than the marginal aero benefit of a hookless interface.

The protocol could be optimized, how much you're leaving on the table should be better quantified.....there is definitely more work to do here, but it doesn''t seem anyone is interested on hard data.

We can do all kinds of mental gymnastics to get Silca to spit out a number below 5 bar. I never said Silca was right, I said my results are more like Silca than Zipp that chooses to ignore road conditions.

Dan, have Zipp send a wheel to Ronan. He is aware of the protocols, he has the equipment. Heck, send him the wheel and I am sure he'd come to Girona and we can find some interesting riders to test.

I did order myself a disk brake bike, just for hoots, to do more testing. There are things I've wanted to test as an AGer for a long time so I talked my Plasma 3 TT rim brake bike to share the garage. The tests are targeted to AGers wanting to quantify the BS level of some of the claims being made by manufacturers. Interesting enough, I was speaking to one manufacturer about something else, stumbled on my little project and he said "here, make these part of your experiment, no strings attached". That was cool.

i guess you must agree that it is likely that the companies you talk to are not 100 percent transparent as they dont want to throw their product under their bus
it sounds to me zipp told you 25 mm was fine, now it sounds they dont say this to you anymore so we cant deny that they where likely not too upfront with you or had mistakes in their protocol .
its a bit like how enve said a rear disc is not faster until they produced one and suddenly it was faster...

btw what is the accuracy of the inbuild pressure gauge , ie i see this as something potentially very useful. how easy can it be replaced and at what cost.

so i think you would be wise to take your claims a bit back until you have really solid data that backs up your claims. if you are interested in a evidence based approach and not just your gut feeling.
just to be sure i am not saying you or the companies are wrong far from it .iam saying at this stage the only solid answer is further research is needed. and till then i guess only people that have done proper research should share their experiences and a maracg does still with the cavet that this is not the conclusion yet... which is good science i would think .

A $3000 disc wheel that isn't lenticular and requires a 60psi 28c (or wider) tire. That's a bold move Cotton. I'll bet they sell tens and tens of these.

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Dimond Bikes Superfan

At least they have finally got rid of that terrible sticker cover and copied DT Swiss' removable hard cover.