Also, try adjusting the stabiliser rods. Your footplate may be tilted too far back so all the pressure is on your heels. If you move the nuts down the rods a bit it'll tilt the footplate forward slightly, see if this helps at all.
np, i see what u mean.. tell me you didnt get youe bocks like tht? or are they a more expensive version?.. if not where did you get that knee bit from and such
They are the kid's model, they are for kids between about 8 and 14. You can only jump about 1-2ft on them, they are a lot easier to bottom out (because of the smaller spring) and generally no way near as good as the adult frame/springs.
Also, the plastic bindings wouldn't be strong enough on the adult model, hence the kneebar.