max psi is/was 72.5 on those wheels. as 128lb rider 58-60psi is my norm on 28mm road. but lmk thoughts
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I’m so glad you’re safe!! I definitely would have 
my bibs after that incident.
Glad you are OK….certainly scary stuff.
But it should be noted that using a 28c tire on those rims is consistent with ETRTO standards.
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I ran your numbers in SRAM calculator, I get 49psi front, 53psi back. Besides, what is the point of running tubeless and a wide internal rim if you are going to pump it that hard?
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with your blessing let’s stay focused on how and why the etrto updated the guidelines and what ramifications that might have for us all. The psi debate is too subjective and personal to the rider and preferences. 10 calculators will give you 10 different recommendations/ranges and 58-60psi is what felt best for that wheel and tire combo to me. All that said , being well below the max of 72.5 psi means that prsssure shouldn’t have contributed to the blowoff imo.
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Yeah but not everyone is small and lightweigth, as a 190cm 81 kg rider i get Pressures of 64/68 for 28cm tires… If you can’t run them at 70psi without the risk of blowing them of the rim then the whole system is badly designed and they need to rethink their whole approach with Hookles and ultra wide internal rims…
I have a pair of Zipp 303s and didn’t have any problems with 28c and 30c tires until now, but as soon as I have the cash for another wheelset they will be back to gravel duty only…
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Stories like this are why I actively avoid hookless rims. I don’t think we can conclusively say the cause of this incident, but hookless is definitely a leading suspect, along with the rim to tire width ratio. Most likely is that specific combination since many people run i25 rims with 28mm tires.
When I look at hookless rims I see no benefit for me, only increased profit margins for the manufacturer (hookless requires less labor to make). If there’s no benefit for me, then there’s only risk in changing. And the bike industry isn’t known for high levels of quality control. There’s still issues trying to use certain combos of tubeless tires and rims, even sometimes with tubes! Given the consequences of tire / rim failure, especially on the road bike, count me out.
ETRTO is conservative in specs and show to change, but given the consequences of failure, they should be.
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This simply is not true.
The combination in question on this incident met ERTRO specs.
If the bike industry is so known for quality control, then how come we have dealt with years of creaky press fit bottom brackets from most manufacturers? The same press fit that was introduced to deal with poor quality threaded BBs?
Or again tubeless tires and rims not matching well in diameter and fitting too loose to seal or being so tight that they are impossible to remove with regular tire levers in case of a roadside flat.
Yes, the current ETRTO spec allows this. I expect them to act quickly if they believe it’s causing problems.
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Because it was a poor application of technology to an area where it didn’t work well.
That statement is ahistorical. Pressfit BB was introduced so manufacturers could have something “unique” and “differentiated”. Others then followed suit, because the bike industry tends to follow trends (which is one of my biggest complaints about it).
That is because there was no industry standard, not because of poor quality control. Tire manufacturers were doing their thing while rim manufacturers were doing theirs. And let’s not pretend that there haven’t been tight and loose fitting tires for decades prior, although admittedly not to the same level.
I’m not here to defend hookless…I am not sold on it. But these ideas that it is about profit over safety or that the bike industry doesn’t have good QC are factually wrong.
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But this is exactly the issue that the ETRTO standard addresses. ETRTO standard on tubeless and hookless bike tyres was published in 2020. Prior to that it was pretty much a free for all with the rim and tyre manufacturers doing their own thing and you had to go digging through Google trying to figure out which tyres would fit on which rims. Since then it’s become much easier - all hookless rims and hookless-compatible tyres comply with the ETRTO standard, and as a result there’s a growing list of wheels and tyres which (in my experience at least) offer a very similar and consistent fitting experience. I’ve got one set of hookless and one set of hooked rims made since the ETRTO standard came out, and have used hookless-compatible tyres from 4 different manufacturers - Conti, Schwalbe, Vittoria, Pirelli - on both wheelsets with no issues. Prior to that when I first tried to go tubeless in 2018 it was a nightmare - first set of tyres I tried every trick in the book to get them on, eventually had to heat them up so much with a hair dryer that I worried I had damaged them in the process, then when I got a flat that wouldn’t seal or plug I broke 2 levers trying to get them off and eventually had to get a taxi home and then cut them off.
Bike wheels is a competitive market with plenty of different manufacturers. So an ability to make good wheels more cheaply doesn’t just mean increased profit margins, it also means cheaper wheels. Not just in theory but in practice - Zipp 303S retail in the UK at about £850 for a set, that’s amazing value for a wheelset from a big brand manufacturer offering lifetime warranty. Enve Foundation are also relatively good value (at least relative to what Enve normally sell wheels for!) and have seen them on discount a few times.
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Regardless of ETRTO, I want nothing to do with hookless for road as things stand.
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I don’t mean to hijack the thread, but is there a consensus that hookless is safe for wider gravel/MTB tires?
I’m so glad @Bigevil is safe after the blowout with road wheels/tires, but my MTB rims are hookless. Just want to make sure I don’t need to be worried.
Thank you!
After hearing this story I can understand it. I have hookless on the road bike too. I’d like the tires to be an absolute bitch to install. Plus an insert. Then cut’em off at end of life. When the review is like “easily put them on without levers” I’m thinking…maybe that is a bad thing?
Seems like if we have big commercial jet tires pumped up to like 300psi working without hooks we should be able to have bike tires without hooks too.
Thanks for ruining descents for me! ( JK 
)
Joe
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Reading this makes me question the “advantages” of hookless rims and whether those outweigh the unintended consequences & costs?
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Well, we heard the same logic re: pressfit bearings. "Well they work wonderfully in aerospace applications, so they should be fine for a bike.
Some of the major differences I can see are sidewall stiffness (who cares how supple a plane tire is?), rim construction, hysteresis differences, etc.
Similarly, we use TPU for many of our upper arm BP cuffs…but we don’t use it for our wrist monitors because it is not accurate in that application. Why? I have no idea…on its face, it should work. Same concept, just smaller volume and lower hysteresis. But the data doesn’t lie. 
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2 piece wheels that don’t require a tire to be stretched over the rim to install is how those work. The fact that you need to be able to stretch a tire over a bike wheel means that it can in theory stretch itself off in the right circumstances. Commercial jet tires have wheels bolted around them.
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Oh…well that makes perfect sense, thanks 
I’d kinda like my tires to be bolted to my rims too!
Joe
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The closest thing you’ll likely get is inserts, which aren’t exactly like a 2 piece wheel bolted around the tire since it still has to stretch on, and more like a beadlock you’d find on an offroad or drag application for cars. A 2 piece wheel is somewhat more feasible now that we have disc brakes, but still not really something that would work for a bike wheel.
That or maybe one day someone will design a means to install an airtight bladder inside of the tire that will provide an outward pressure against the tire and help lock it into the rim. Sadly I feel this technology will never come.
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