In my experience, I'll get some popping during the initial CO2 blast, enough to keep the tire on the bead when I deflate it (to let the CO2 out, and replace it with fresh air). I'll typically drop pressure to 20psi, then pump it up all the way to 120psi to get it to completely seat.

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I own a lot of Treks

Yesterday I was riding our club's so-called Torture 40, it's a 68km route in the Chilterns that packs in 10 steep little climbs. The roads are mostly single-track lanes and as such rarely maintained, frequently pot-holed and always gritty. I rode straight after a rain shower so the puncture risk was high. I was well through the event on a shallow descent when I began hearing the familiar sound of a puncture. What I had never seen before was little gouts of sealant spraying out of the front wheel. I watched with interest. After subjectively a long time but probably about a minute the sealant stopped appearing. I carried on and completed the ride, highly pleased that a puncture, for the first time ever, had not stopped me.

Checking at home I found that the pressure had gone approximately from 90psi to 45psi. That pressure was still rideable though. I have pumped the tyre back up to full pressure and it does not appear to be leaking. I am highly impressed with tubeless!