The Yakima Rack and Roll Trailer Heavy Duty Shocks are a recommended upgrade when carrying 1 or 2 cargo boxes full of gear.
The Heavy Duty Shocks restore the load rating to 250lbs.
Increases your 78" trailer load rating to 300 lbs. (with no cargo boxes).
Note: Do NOT carry over 250 lbs. on the 66" Crossbars, even with Heavy Duty shocks.