This indeed has been asked many a time. You can get away with DMR tyres if you have good tubes. I've got a big high roller on the rear and a schwalbe tabletop on the front, which is dead light. If you want to do street, I might suggest a pair of DMRs. If you want to do more trials, a rear kenda blue groove perhaps, and a front DMR If you want to do mostly trials maybe get the smaller high roller, it comes in two sizes, and a DMR front.