Before this trip, I had had many rides in the deep cold, but they were on a mid-’90s rigid Kona. For the jbd, we weren’t sure what setup to run – tubes or tubeless? A quick search online of “does tubeless sealant work at -40 C?” was no help. There’s lots out there about sealant in cyclocross season where the temperatures are rarely as low as a balmy -5 C and where wheels are exposed for an hour or two at most. We were riding the newest 26" x 85-mm Woven Precision Handbuilts carbon wheels with 45nrth Dillinger 5 studded tires. We tested our gear in the -15 C range a few weeks prior to the trek and all agreed to stick with it. The idea of having to change a flat in 30 below is enough to make one ill. We brought a few ultralight tubes for backup, but we had zero issues. No burps or flats. The rims and tires were a tight match. We took air out as the days passed and the sealant stayed fluid. Every one of us started with too much pressure and the crash counter went up and up. Ted had the fewest, but one real beauty.