@ JCL: some pretty good points except if you look at how I load my tools, they are very CG forward. about 14" or less from the hitch pin (i'll measure at some point but from the photos, the 2" ball appears about 8" from the pin; the spacing of the bars in the rack is just about 4" center (16 inch front to back).

The pin is a reference for 'the consumer' and by no means the torque axis. based on how far the mounts go into the car, it would be fair to consider the center of the main cross bar the 'axis' for torque calculations. (the entire assembly is robust enough to consider nearly solid); solid enough the effective torque center could easily be forward of the crossbar because of the amount of body work that becomes part of the mount. In fact, when i do my measurements I will use the vertical plate as the torque axis until i would be shown why that would be at fault.

I didn't measure but it's a 2" bar at least; it's at least 2-3" forward of the hitch pin, so.... if my CoG is 12" behind the pin that means 15 from the axis, and using 600x11 as the rated torque, divide 6600 ÷ 15 = 440; so for a CoG in the front 25% of the 16" rack, I would be quite comfortable in saying 400# as mentioned earlier.

If i extended the CoG to center, than the ratio is 600x11÷19 or roughly 350#, only double what i'll every be loading. (other than the static load of 4-5 people sitting on it at a tail gate party). (which the hitch won't even notice; if it can handle 600# on a road or 350# off-road it'll handle double that static easy).

It is a very good idea to 'pull out the slide rule' occasionally and make sure common sense prevails, but i'm not the least bit concerned that my 120# of tools will be even within 33% of the capability of the rack/hitch/mount.

I 'only wish' i could apply 'off road' to the equation. Even so. 350 x 11 ÷ 19 = 200#, so the rack 'as is' with a CoG centered front to back would handle 200# 'off roading' I'm good with that.

I *always do the math*. I'm quite confident i'm nowhere near the 50% safety margin I will usually design around, and as I approach the 2:1 ratio i'll get more serious about measuring details.

A rough estimate of the original design before mod: 13" Cog from the pin = 16" to torque center means 6600÷ 13 = 507 #; imagine that. rack is rated 500# coincidence, notsomuch, i would argue a good case of using the crossbar as the torque axis making sense. (and most certainly not the hitch pin).

-awr