you will get this with flex, have a look at the screws that hold in the hinge pins. ie the hinge pin holders.. they tend to get loose, i had a race last tuesday and my front uni popped out 2 times, i replaced the hinge pin holder and no more problems.. also pull your castor in to shorten the uni travel.. Um what elce ..... thats all i can think of, good luck

Sorry forgot to mention it was the lower hinge pin holder... check both though