30mm is a little narrower than I would have expected, since my 25mm blow up to just around 29mm, but not by much. I guess I would have expected 31-31.5.
As for mounting, yes I need a blast from an air canister to get my 25 and 23mm pro ones to mount to my HED rims.Its easier after the tires wear a bit but just using a floor pump in insufficient. With new tires, replacing the rim tape helps with sealing the first time. For a while I used a coke bottle compressor hack, which worked,but recently bought an airshot canister because I feared coke bottle explosions.
But I have not had an issue with tires staying seated. The tires stay locked to the rim even when completely deflated. In fact, whenever I have deflated a tire to remove it, it takes considerable pressure to get the bead to disengage from the rim. I also can get tires to mount without levers, although its not easy. Levers make things easier, and since there is no worry of pinching a tube, I usually use one.
As far as unpressured bead seating - I'll have to see how it goes after the tires have been mounted a while. I had seated the beads, then deflated them to insert sealant and the beads did pop loose. I did have to reseat them with the compressor after adding the sealant. The whole thing did seal up super tight pretty fast though and I'm happy with the mounting.
FWIW, these were a pair of 28's I'd bought more than a year ago and never got around to mounting. I'm wondering if newer manufactured ones do a better job of staying locked to the rim.
J.