Originally Posted by
DesertRat
The center pivot is actually compressed during entry into the corners as the car scrubs speed and the weight tries to shift forward. It goes to neutral then to full extension as the car transitions to mid corner and exit under power as the motor torque causes the motor to try to "climb" the spur gear, lifting the center pivot. The entry to the hardest corner is the spot where the center is most compressed, or possibly an off-power high speed sweeper.
So basically after every slow speed corner when throttle is applied. An o-ring is probably easier to do than a spring. Many 1/12th shocks will not have that much down travel built in.