ORIGINAL: Lantern
When you say "every bump and jump" do you mean every one that should involve air time? Meaning a significant jump instead of a bumpy track. If you mean a bump or jump where all tires are leaving the ground then I would think there is a problem with the breaks dragging. I'm currently battling this problem as well......sure makes flying my LST interesting!!
If the problem is just handling bumps I would suggest softening your suspension at the end that is bouncing the most first and work from there.
If you are having problems with the brakes holding to much, you can try adjusting the brakes by tapping the button just to the left of the steering wheel (Left as you are looking at the radio controller) The way I got mine set correct, or at least close. I set the truck up off its wheels, while it idled with the controller in the neutral position, I tapped the button until the wheels stopped spinning freely. I then tapped the other way til the wheel just started to spin slightly. Before I did this, the truck would start going on its own at idle while in neutral. I may still need furture adjustments, but it seems to be close.