Originally Posted by
terrymorse
Yeah, that was the type of thing I was thinking of that would unseat a tire: rolling while fully deflated.
I've gotten a few rapid deflations from large punctures while riding clinchers, so I continue rolling straight and brake gently. That several seconds of rolling drops the tire off the rim hook, where it can still be ridden safely. Unless the tire fits really loosely (modern tires like GP5000 are tight), it's not going to come off the rim.
The whole deal here is that while making a high-speed descent if a tire fails, because of the higher forces involved the chances of the tire unseating are higher .... even a lowish-speed downhill corner will possibly pull a tire off before the rider can safely brake to a stop (he said ruefully, picking up his bike, his bottles, his lights, and his scraped, bruised, battered, bleeding body.)
In other words, experience has taught me that any sort of clincher tire, tubed or tubeless will come off the rim if you keep rising it ... and yes, the tire will for a while ride half on the rim, which makes handling very sketchy, but in my experiences I have not been able to keep on riding safely on a deflated clincher. It has always either dumped my by sliding back and forth, (so that I am balancing on a rim edge, and alternating between rim edges, with one rim edge atop a sliding rubber cushion) or has come off and jammed in the brake or fork.
I have never ridden tubulars, but I would bet coming downhill at speed, a rider would feel just as unsafe because the tubular would grip the road while the rim would shift side to side .... but it might be safer for the amount of time needed to get the bike safely stopped. Not intending to perform that test.
And pretty much none of that has to do with WHEEL failure.
if the thread were titled "Is descending on anything but tubulars worth the risk," well, that is not this thread.
So if the OP deems either wheelset to be safe enough regardless of which tire style it uses .... then we are back to choosing which wheel based on other criteria.