Fully agree that it isn't a straight cantilever. That said, the 600 lbs tongue weight limit has no relevance at anything more than 8" from the pin to the CoG of the load. It would be like saying that a bolt was overtorqued to double the specified torque, but it is OK because the tech used a longer wrench to accomplish it. Torque is torque.

I don't have the distances or weights for this carrier, but a sample calculation would be:

240 lbs bike, plus 60 lbs carrier, equals 300 lbs.

Load being applied at 24" vs 8" spec is a three time multiplier on the bending moment, so 3 x 300 = 900 lbs equivalent tongue load.

Using the OE hitch, it would likely survive. That assumes the load didn't bounch at all (which has a 1.8 multiplier effect, recalling limit of 330 vs 600)

Using an aftermarket hitch, no idea. But it appears to be surviving so far. I would still inspect the trunk seams from time to time.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue