Originally Posted by
Kapusta
Well of course.... but I don't understand what point of mine you are addressing here.
The issue is not whether it helps retain the bead seal against the bead seat, it is what happens if that seal gets broken. The same bead/tape contact that lets you seat the bead easily is also what minimizes the air loss before the bead re-seats. This happens very quickly and you might not even know it happened. If there is too much of a gap there, that can result in a very large and sudden loss of air. This is what burping is. And a big burp is a nearly instantaneously flat tire..... and usually this will happen at the worst possible times (when the tire is encountering some hard side load).
If a rim really needs no tape, that would mean you are not having to go through what you describe to get them to seat. If you don't put tape on a rim and need to go through what you describe, it in fact DOES need tape (even if there are no spoke holes), at least with that tire. Whether or not the rims are hooked or more of a Stans design is irrelevant to this.
Here again, I fundamentally disagree with your presumptions and conclusions.
To reiterate, tape has nothing to do with proper tubeless fit, and ideally, is not used at all, because it interferes with the the precise mating of the bead lock (on the rim bed) and the bead. Tapes only purpose is to seal spoke holes, not to ensure fit, and in fact, using tape to achieve fit is a kludge for less-than-ideal rim and tire bead seat diameter matching. The whole reason hookless rims work is because of the precise fit of the bead lock and bead; sticking tape in there softens those interface edges and reduces the efficacy of the bead lock.
If your rim and tire don’t fit together properly, that’s where tape comes in, but that’s not how tubeless should work. Using air, on the other hand, to seat a bead has no impact on the fit; it does not alter the bead-to-bead lock interface, or anything. If you can blow a bead up into place and it holds air, that’s as good as it gets...presuming you’re using a proper tubeless tire with correct fit and rigid bead construction.
The reason we have these issues is because tires are not manufactured to the tight specs that, say, car tires are manufactured to with regards to bead/bead lock fit, so we’ve taken to relying on tape to make up for those failures. Similarly, molded, hooked rims are not not manufactued to the same tight specs, either, so again, tape is a hack to make up for it. Some rims are proper, and some tires are proper. Air is always the same, and has no impact on fit whatsoever, so if you get the bead up just using air, even if you have to work the tire around a bit, that means you either have a bead with an interference fit on the rim bed, or you have a perfect rim/tire match up, but, having beads with an interfernce fit on the rim bed (i.e. before seating) does not mean you have good fit when seated.
Again, my view is that tape is not a part of good tubeless design, but can be helpful when the tire and rim are not matched perfectly or you have insufficient air volume to position and move the bead.