A bunch of my friends want to start trail riding together and progressively work into harder and harder stuff. I am not sure the year but I have a well taken care of Klein Pulse Comp. I ride it on some easy trails but haven't done anything actually hard. Is it capable of keeping up with modern day mountain bikes? They used to retail over a $1000, so I figure it should be decent. Should I upgrade anything on it? If so, what? I don't have squat for money right now so I can't really buy a modern bike or I would. What's the difficulty of trails this bike could handle?