Originally Posted by Racer Ex

On the road, one in the last year. Big nail. Noticed a shimmy going down SGC road at 40. Did a little bunny hop and realized the tire was deflating. Rode another couple miles to a turnout, stuffed a tube in and rode home.

Had one other flat from a piece of wire at some point in a three hour ride year prior, tire leaked out overnight. Removed wire. Patched the inside. Eventually wore the tire out.

That's been it.

My evaluation on the relative safety of the different wheels is presuming proper installation, going beyond that is kinda silly, like asking which car is safer for a blind drunk behind the wheel who isn't wearing his seat belt. People pinch tubes putting on clinchers (bang/crash) or don't get the tire mounted right (bang/crash) and some people do a lousy job gluing tubulars (roll crash). Hard to put a tubeless tire on wrong. I suppose you give a bad mechanic a chance though and they will find a way.

Presuming proper installation you are talking about the results of a puncture.

For a non catastrophic puncture a tubed clincher will deflate much faster because there's no mechanical seal to prevent air escaping. Air comes out around the valve stem, through the rim tape, through the puncture, and through the tire itself, and the sidewall when the tire deflates to a minimum PSI. A tubed clincher will come off the rim once it's deflated to a certain point, there's no mechanical design to help hold it on other than the pressure of the tube itself. So you end up on the rim and in some cases with the tire wrapping into the frame and locking up the wheel.

Tubulars the air escapes out the puncture only and sometimes nominally around the valve stem (glue creates a seal at the base tape both on the rim side and the tire side). You get some warning as the tire goes soft. Glue helps hold the tire on which provides more control and it can be ridden flat.

Tubeless the air escapes out the puncture only. You get some warning as the tire goes soft. The tire bead is designed to hold the tire on and it can be ridden flat (I've done it, though only once as a test; I've ridden multiple tubulars flat so there may be situations where the tubeless might detach). If you use a latex sealant this will actually add a glue effect.

Catastrophic failure (big cut) and the tubeless and tubular stay on the rim to a much greater degree.

In the cases above it's clear that you have have a greater margin of safety with tubular or tubeless from a simple design standpoint.

If someone wants to send me $500, I'll do a Youtube video where I'll ice pick the three designs, time the deflation, then go ride them around.