I've got some Crossmax and they will run with tubes but I found that its a sod to get some tyres to seat well - tried Panaracer Fire XC pro and Conti Vapour and they didn't really want to know. Suggest plenty of soap round the bead and pump them up to at least 60 psi to get them to snap onto the rims even so they might just be rather wonky and you'll need to try a few times. Now using tubeless with sealant and its worth doing IMHO.
PS. If you don't need the valves anymore then I'll have them off you.