I have put 27 zillas on my Kodiak with stock suspension and clutches. These tires work well on just about everything I have thrown at them. Mud, creek gravel, hard pack, and even run fairly smooth on asphalt. With stock settings in low gear they bite hard and will stand the bike up from a stop. Plenty of power for mudding and hill climbing. No noticeable power loss as these are very light albeit aggressive tires. 27's have one and an eight inch tread. Best part is I can go places in two wheel that took four wheel before.