Did some measuring. 19" from axis to CoG for my main load. 4" inside from pin = torque axis (my estimation: it's where the main crossbar bolting plate is)

600x12 = 720 ft. · lb torque divide by 19" and it is: 378. Darn close to my "seat of pants" 400.

Thanks for bringing the detail to my attention. I've seen plenty of bumper mounted external cargo kits at a 15° angle because they don't realize they are applying 1000-2000 ft·lb of torque to something inside.

The flip up adaptation adds 4.5 inches. The center of the rack is 24 inches vs 12 to the rated 600 means 300 is a perfect value for the rack evenly loaded.

Without the added length the # works out to 370#

Off-road: 350 becomes 175# (again thanks for bringing to my attention but doesn't apply to my $5000 worth of Milwaukee tools that will be driven to a job on smooth paved roads)

I only lose 70# capacity for the flip up convenience.

One last calculation; hopping off the end: 2 1/2 ft x maybe 250# impact a mere 750 ft•lb of torque.

Assuming at least 2:1 3:1 safety design factor and 600 ft•lb rated the hitch should be able to handle impacts on the order of 1500 ft•lb (load transitions, pot hole induced shock etc). The fact they derate to 350# for off road indicates maybe closer to 2:1 design margin or 1200 ft•lb torque rating (if the axis is where I think it is: sure makes calculation easy being 12" from the rated 8" from pin)

-awr


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2011 E70 • N55 (me)
2012 E70 • N63 (wife)