Hi stepheng,
The security for my Cub Escape is a pair of high security chains with good solid padlocks.
also when I am towing the Cub Escape I put a padlock on the safety chain chain along with the D link.
From the local locksmith I purchased 2 x 1.25M lengths of special security chain, it is meant to be very hard to cut. It came with the black sleeving to protect the wheels from the chain, I also got 2 good quality ABUS padlocks both locks use the one key.
The chains wrap around the wheel and the coil suspension frame nicely.
It cost me approx $290 for the locks and chain, This should make it a bit harder for someone to nick my trailer. Sure I have insurance but I would prefer not to have to claim, to much work went into this Cub Escape.
HTH
Ray