Holding Mobile Goal

Our robot seems to be having trouble with the mobile goal sliding out of the mobile goal lift as we drive around. The lift seems pretty typical with a 5x5 piece of C Channel lifting/holding the mobile goal. What are teams doing to keep the mobile goal in place? Is it just a matter of driving a little smoother so as not to let momentum come into play?

Simply wrap a rubber band around the bottom of the c-channel (what the mobile goal rests on). This works well for us, and several other teams I know of.