I rode my rigid Cindercone with a 1.8" on the front and 2.1" rear on Thursday offroad. Trails were dry and dusty in places and the tyres were great, absolutely flying! However, wet rocks were hard work and they clogged badly in gloopy mud. Having to ditch the 2.1" on the rear as when they clogged up I was struggling for clearance against the seat stays and chain stays. Nice looking tyres that suit my old Cindercone, however don't think I'd use them on my XTC or FSR.