Originally Posted by
vespasianus
On the MTB side, hookless rims have had wide use for a long time. They work well and I run my 27.5 x 2.4 tires at 15 PSI (200 lbs) and love the ride. Never once even burped a tire at those levels.
You just touched on why they "work" over there= 15 psi. The issue isn't about burping on road it's quite literally about tires being blown off the rim. Its the other end of the spectrum.
The most troubling thing for me is that the parts of the industry that will talk about it openly just use in house rules of 150% of target pressure. That's a 1.5 safety factor. That's the LOWEST safety factor I have ever run into in my engineering life. Especially in a consumer product. The worst part is that not everyone even agrees on going that "high". Hushed anecdotes say some OE's have been fine with 1.2-1.3. Think about that: If they are rating a particular tire and rim combo to 70 psi then that means they have experienced blow off at 84 psi. Keep in mind that even all these years after we went to "wider" 23mm rims (13 years ago) we are still having an impossible time convincing people not to ride pressures in the 115 psi range for road. Old habits die hard. This is an absolute recipe for more than a handful of deaths. Also...84psi? how accurate is your crappy pump that you've used for 15 years? I've run across new *redacted* pump gauges that are as much as 15-20 psi off at lower pressures.