The Stryker has two indentations in the handgrip, just above where your fingers would be holding. Try to balance at that indentation. If the aircraft tips forward, it's nose-heavy. If backwards, it's tail-heavy. You can adjust the center of gravity on a Stryker by moving your battery forward and backward. I apply Velcro tape to the battery and the inside of the battery compartment where I want my batteries to stay still.

There are other stops on the road to a perfect-flying Stryker, but that's the first station. If the CG is off (nose or tail), the Stryker flies horribly, as does almost any other plane.