1) the rails pivot in the middle at the bottom of the arm. In order for the sled to pivot back relative to the rail, one of two things must happen; a) the front of the arm must get further from the rail (meaning that you need to have some slack in the straps), or b) the middle of the rail must compress up into the sled (meaning that the spring must be unloaded enough that it can be compressed some).
2) in order for the angle of the rail to change relative to the body of the sled, the transfer/softness arm must be able to change length. You say that you have the transfer set on maximum, thats good, but not good enough. I see from the picture that you have the rubber bumper still in the transfer gap. Remove it. I haven't been able to figure out why they put it there, but it basically seems to be there just to make you crazy. It limits your transfer and at the same time prevents you from limiting transfer. I know thats a contradiction. Accept it.
3) 2 feet of ski lift is excessive. You NEVER want your skis up that far as it will SERIOUSLY slow you down.
4) Without enough traction for your conditions, you'll never get any transfer. The skid can't magically lift the front of your sled up off the ground -- inertia does that. As the track transfers the engine's power to the ground and accelerates the rear of the sled forward, as Newton put it, "an object will remain in a state of rest or uniform motion unless acted on by an external and unbalanced force". That means that the engine will try to remain where it is as the track tries to drive under it. Thats where transfer comes from. It lifts up because the force accelerating it upwards exceeds (i.e., is unbalanced by) the force of gravity. If you have no traction, then the upward force will never exceed gravity.
Now if you want to flip over backwards, its real easy. Use the crest of a hill to help you get lift. Pin the throttle at just the right moment over just the right hill and the front end will accelerate upwards as the back is forced down hard. I very strongly recommend that you be careful though, I don't think you want to do a back flip as I've heard that it can be quite painful and expensive. Note: I will not be held responsible for any damages, injuries, or death that may occur as a result of irresponsible behavior.
Also note: Because the springs act on the pivot point, the full rails will pivot freely when the sled is lifted. That means that when the sled is lifted off the ground, it doesn't mean anything if there is or is not slack in the straps as you can change this by just pushing against the rail. This same free pivot design is the whole reason why this skid transfers so well.... conventional skids have two springs that balance the rail and prevent it from pivoting freely.
So to recap; to achieve maximum transfer, set transfer rod on maximum and set the preload and ride height low to maximize available slack in the straps (when the sled is down and you are sitting on it), but don't set the preload too low as this will cause the suspension to collapse. You also need to have enough traction and power to lift the front of the sled.
Also; The softness nut has absolutely no affect on front to back transfer, it will only affect back to front transfer (i.e., it has a slight control on ski pressure when you're slowing down)
