In the trees the 650-155"x2.75 is more than capable of keeping up with the big machines. You just need to hit the volume control more. That being said, it still gets better gas mileage while doing it. The 650 may not be a lot lighter, but with the incredible throttle response, it feels way lighter. If your into big hills or handle bar deep riding all the time, the 650 just does not have the torque of the big sleds so it will suffer, do a bit of poaching and again it will hold its own no problem. For normal tree bashing it comes down to rider skill and sled set up. I have ridden with Cats (Alphas, Ascenders, HCRs and Proclimbs, Doos (800 T3 174s, 850 165s, 900 big bore and 850 Turbo 165s) and at NO TIME did I struggle to keep up and usually am up near the front of the group and whenever possible making my own trail through the trees. On several occasions embarrassing some of the big sleds on the trail in, across small lakes in the back country and in the trees. That being said, I think mine is well set up and I am a pretty good rider for an old guy and maybe some of the guys I have ridden with are not very good riders or maybe their sleds are set up poorly or both?
Bottom line, its a GREAT sled. I call it an Over Achiever. Last ride out one of the guys told the rest of the group, Maybe he's on to something with that 650.
Here's the best part, if they beat my 650, who cares (If I had a 800 or 850 or Turbo) I wouldn't brag I beat up a Grampa on a 650 with a Snow cross track. However, if Grampa on a 650 keeps up or beats them, now that's something.....................
