I generally get tyres on easily by pushing the beads into the well of the rim and talcing the tube (a lot of the friction is caused by the tube, rather than the tyre against the rim). However, Vittoria Open Tri Evo on Exal XR1 literally left my hands bleeding and raw. The good news is that folding tyres, while often hard to fit out of the box, always loosen up after a couple of weeks inflated on a rim. Tyres that were nearly impossible to fit become removable by hand on the road. I don't carry tyre levers when riding most of my bikes.