Calvin Pollet, the designer & fabricater of the Cheetah Cub & the Sabertooth cylinder, which lives in South Coffeyville, KS, personally told me that they are NOT trail friendly. But they can be made that way with different port timings and certain carbs. Different port timings ARE NOT detuning a bike either, it is just giving you a different power curve at different times under the throttle. He also said that the smallest carb to use with these would be a 34mm carb. So obviously from his statement, if your using a stock carb or slightly bigger, your gonna lack full potential out of these cylinders, and mostly to utilize these cylinders, he said to make sure and go with alky carbs....If the cub gets enough air and alcohol, it will perform with the best of all worlds, but if you're wanting a trail cylinder, I wouldn't recommend going with them. Just my .02....