Hard to generalize but most carriers I have built and have used and been impressed by their ease of operation have had a small amount of preload so to speak so a loaded carrier will line up with the latch properly and open close smoothly when loaded with a tire etc. While the hinge is carrying the majority of the weight and is capable of carrying that weight, loads change with inertia on a moving vehicle over a bumpy road. The latch side does provide a substantial amount of support in these situations. To be quite honest I am surprised the rear door does so well in holding the whole enchilada shut and secure as it is designed with the AEV and other systems relying on the door to keep it closed. While there is not vertical load there is considerable back and forth. Leverage some more weight out on the end of that mass and the load increases.
That said I really like the IBEX mount and would like to see more from them.
I know that on the AEV carrier I think that AEV has said that the way the carrier is setup there should be roughtly 20% or the weight supported by the swing gate, and 80% by the frame. The tire carrier is rated up to a 40" tire, so I would guess on weight you are looking at about 140-150 pounds that the tire carrier is designed for. If you have a 37" tire (mine is around 100lbs) and then add another 40-50 pounds a few feet to the drivers side of the carrier I would be exceeding the design of the AEV bracketry that secures the tire carrier to the body and still allows the independent up/down movement for the body to frame flex.
I figure that based on my wheel/tire combo I am placing about 20 pounds on the body, and 80 pounds on the frame. I don't have any exact measurements, but if I assume that the spindle to the center of the tire carrier (where the weight of the tire is centered) was 3', and I decided I wanted to move my tire towards the drivers side 4" to center it on the carrier I would be moving the weight towards the drivers side about 12% on the tire carrier, and increasing the amount of leverage on the spindle and changing from a 20%/80% spilt to a 32/68% weight distribution (I over simplifying the process since I am not an engineer). It doesn't sound like much weight, but the swing gate is rated for about 50lbs (stock Rubicon tires are pushing the limits of the JK swing gate). Based on the math here at some point I am going to move the leverage over enough I am going to exceed what the tire carrier was designed for.
I am not sure where the weak point is on the AEV tire carrier for the load, but you have the spindle and the saddle block that take the weight and distribute it into the proper components. I could see where the Ibex mount with a chainsaw, and a Power Tank could be adding 50-75+ pounds about 12-18" towards the drivers side of the tire carrier. This would probably be far enough past the tire carrier that at least half, if not more of the weight is supported by the saddle block and the swing gate. Now all of a sudden my 20 pounds on the swing gate is up to 50+ pounds, and this is a factory part that is rated for about 50 pounds.
I think that the items that Ibex created that mount direclt to the tire with a rachet strap is a better idea because then we are placing more of the load on the spindle (which is designed for the weight) rather than placing it on the swing gate. I am not really looking to store items on the tire carrier like they have shown, but I am looking for a step that can mount to a 37" tire carrier which their system could provide, so I can have easy access from the AEV bumper steps, to a future roof rack for photography.
