Member - Graham H (QLD) replied:

As long as you have them adjusted correctly and go slow you shouldnt have any trouble.
5-6 links are good any less are too short cos if you make a sharp turn doesnt leave enough slack for the bar to move back on the inner side and can snap a bar.
Saw a guy nearly do it yesterday when he had a rig nearly jacknifed and the bar was starting to bend.

Any more and they hang down too much,and dont just pull your jockey wheel up TAKE IT OUT. Friend didnt and destroyed aTrailmate jack on the Plenty highway last week on a big corrugation.