That most definitely has NOT been my experience…
Loose fit = often able to burp a tire by hand just by pushing the tire off the bead shelf…have also had tires burp cornering hard, hitting a bump, etc.
Super tight fit = essentially impossible to burp a tire. I can push the tire off the bead shelf without so much as a wisp of air escaping. I’m a heck of a lot more comfortable with that than some random erto guideline…
Personally I want both the suppliers to make certified product (even self-certified would be a start) and to test it myself.
The air-tightness test isn’t going to test everything. Notice how wall height, inner bump on the bead seat, radii, etc are also specified in the ETRTO specs in the screenshot? Those aren’t being checked by your air seal test, but they are all important.
That radius on the wall top is to keep your rim from cutting your tires. The bump is to keep your tire from falling in the center channel if you mr tire gets pushed to the side in an impact. There maybe other requirements for other failure modes.
Engineering is way more complex than most understand and validation has to cover a great many potential issues. At home testing can’t cover it all.
ERTRO, an internationally recognized organization used to set manufacturing standards across multiple product categories, is “random”, but your “I’ll just use more tape” method, without understanding how the various systems work, is somehow more reliable?
OK, then…
his comment is random and possibly not what was intended? 
My point is that etrto numbers have no bearing on the fit of your tires relative your rim, other than a possible measurement for manufacturers to target. Why would one be more worried about what etrto says the size should be rather than what your actual size is?
I mean, you can stamp your feet all day long and say, “all tires and wheels should be exactly this size!” All day long, but the reality is otherwise. I dont know why you’d prefer to just run a horrible setup rather than fixing it. Kind of seems like cutting off your nose to spite your face…
if several different tires go on to easy, its likely a problem with an undersized rim. Get rid of that rim. With properly sized rims and tires, every tubeless tire install should be a bit of a struggle.
No one has said that, as far as I can tell…but the idea that ERTRO numbers are just “random” and have no bearing on tire fit is just factually wrong.
I think we’re just speaking past each other here.
I’m saying etrto is just a guideline. It is not a physical measurement of your rim or tire.
What? That is exactly what ERTRO specifications are meant to provide. A recognized set of specifications / measurements to ensure a properly functioning product.
Is there a regulatory body to ensure compliance? No…and that has been discussed upthread.
Yea agreed…if the rim is drastically small. Degree here matters though. I’d prefer if a rim is just a tad on the small side. For example…
I set up my current pair of CX wheels 2 years ago. When I initially mounted my tires…they were tougher to get on than a tubed tire…but I was only just barely able to seat them with a floor pump with the valve core removed. Too loose for me. So I added a layer of gorilla tape, remounted tire, which I was just barely, with a lot of swearing, able to get on by hand. Seated immediately with a floor pump. That tire has not gone anywhere over the course of 25 cx races and a few gravel races. I did actually manage to burp about 5psi out of the front tire once…but that was the result of an airborne crash at trek where I landed with the wheel mostly sideways on impact lol…
I’m talking about the difference between target measurement vs actual.
I’m really lost… Just barely able to seat them, and you concluded they were too loose and added a layer of gorilla tape? What voodoo is this? Really don’t understand what’s going on in your garage, but at face value it sounds like you live in backwardsville. I dunno.
By “seat,” I mean pop them onto the bead shelf with a floor pump. I’m not referring to just getting the tire on the rim.
And also…I dont think it’s necessarily a bad thing for it to be tight enough it’s impossible to get the tire on by hand…they make tire jacks for a reason.
Yes I understood the use of the word “seat” but in my language if it barely seats (with floor pump) that means the rim/tire combo is either too tight, or I forgot to spray water on the rim and tire. It doesn’t mean the tire/rim is too loose but hey maybe we are separated by a language gap.
No…I think we’re just looking at it from 2 separate angles.
When I say just barely seats…I mean I have to pump like mad to put more air into the tire than leaks out as I’m trying to get it to seat. I try to set it up so the system is essentially completely airtight with both beads still in the center channel, so I can just slowly, calmly pump the tire up to pressure at leisure.
If the tire was a little challenging to mount, then when that happens in my garage it’s either because a) the rim/tire are dry, or b) the tire isn’t straddling the valve. I’ve had an out of spec tire - too large - and it mounted without any real thumb pressure and the bead set immediately.
Not saying you didn’t have an issue, but I wouldn’t immediately conclude the rim/tire were out of spec and it’s time for another layer of tape. Let alone gorilla tape that for my rims would not be the correct width.
Another Lotto - Dstny tire failure…this time at Strade Bianche.
while Vittoria and Zipp both blamed a rock as the cause of De Gendt’s crash.
Hey Vittoria and Zipp, this is not comforting. An unexpected rock should not cause a tire to blowoff a rim. Cause a flat? Sure. Completely blow off a rim? No.
Zipp really needs to proactively get their arms around this issue. Yes, there is likely a setup issue at play here (and I’m betting on too high PSI as a critical element), but this is a horrific look for Zipp. Especially since they continue to insist that their approved combo (28mm tire on a 25mm internal rim) is fine, despite being outside ETRTO standards.
I am still very much on sidelines on hookless for the road at this point…and if I did go hookless, I would not go over a 23mm internal width. Again, I think a big part of the issue is the “well, more is better” mentality that is prevalent in the bike industry. “23 was better than 21 which was better than 19 which was better than 17, so 25 must be better than 23, right?”
This is a good read:
Josh Poertner lays out the issues - here is one quote
“32mm seems to be the largest size before aero really starts to fall apart, while also being the narrowest size I feel comfortable running hookless based on our internal testing experiences.”
Thanks for posting that EscapeCollective article, it and the Dan&Josh SlowTwitch article underscore what I’ve said over and over - all my road/gravel rims are and will continue to be hooked.
I’m with Josh - hookless is probably the future, not the present 
Both my road and gravel bikes are hooked at the moment. I would go hookless for gravel as I run 40mm tires, but I’m not going hookless road until the inflation safety margins are noticeably increased.