So I mounted up the Marathon Mondials on the ArchEX rims and the fit like a glove. Didn't put in enough sealant the first time so had to pump in another ounce with a home made injector. They are now sealed up nice and am running 27/30psi F/R and the ride is nice but still fast and easy on pavement. I tried as low as about 25psi (rear) and found I bottomed out on a fist sized rock at speed, so it seems 28-30psi in the rear is the lowest I can safely go. I've seen 1-2MPH faster than the same tires w/ tubes on some flat and downhill pavement sections.   (16/16)