If I were building a trail bike my 10mil serval would be my first choice, I'm a big guy and with this setup it just pulls hard at any rpm you can be just over idle in 3rd or 4th gear and just roll on the throttle in the trails and it just pulls. The stock stroke bikes I have rode would just make a gurgling sound and slowly start to pick up rpm if it were perfectly flat ground. There is only one downfall I can find with a 10mil serval and that is it costs more than a 4mil or stock cyl.
It really does make nice power that is pretty smooth and easy to ride.