I like the Swagman too but another thing to think about is the movement after it is installed,that is a big thing to adding life to your bike rack,after all they bounce around a lot while on the road.
I have tried almost every Anti Rattle device on the market, most have been no good or so complicated and cumbersome that they are useless.
While looking for a Trike Rack for my Catrike I stumbled on a place called
Hitch RiderThere I saw a Anti Wobble device and thought I would give it a try.
Their
Hitch Vice is the best and easiest one I have come across and it really works.