Question about bolting through bed material and strength...

So. when i am out camping I use a swing away that mounts in my trailer hitch receiver. For just commuting and general getting around I made a vertical mount that attaches to the slide rail on the end of the bed (with tire weight supported on bottom.) See picture:



Problem with this is I cannot see out the back window.

Someone on here made a cool horizontal mount that attached to the bed side rails and was supported in the cross (2x6) pockets. I really liked the idea but want access to my bed rails-what says the hive mind about making similar item that then bolts to the composite bed in the cross pockets? Only loads would be from bouncing or rolling over (for which I have an aversion...) This will "float" the tire over the bed and allow me to use the back window! Any engineers that might have a perspective on potential failure?

 

So I have bolted many things down to my bed. I have a pelican case with all my tools, some spares, etc bolted to the bed with only 4 3/8" bolts and with all the crazy mess I've done it hasn't failed yet.

I think that is a good idea you have with one modification I would do. That would be to put D-rings on the factory bed bolts then run a strap over the tire to cinch in down to the floor. That way it takes some of the fore and aft as well as side to side loads off the mount you are talking about doing. Heck I have my tire ratchet strapped to the front rail then one that goes over the top and cinches it to the floor. This took away a lot of flex I was seeing just attached to the rail.

 

I am planning to use a steel circle with studs for the wheel to be bolted to, that will be welded to the cross pieces that bolt to the bed. I have the D rings already... not sure they should be needed with the tire bolted to the cross pieces bolted to the bed...

So you don't think the weight of the wheel and members will destroy the bed with a plate and say three or four 3/8 bolts at each point of contact? Seems stout. just not sure about the composite material.

 

I'd have a plate under the mount as well so that you sandwich the bed.

Cross pieces??? I'm not sure I'm following you on that part.

 

Use about 1.5 sq inch backer plate for each bolt used based on the sizing of Toyota addon bed D rings design. If I understand you are bolting through the horizontal 2x6 bed pocket which should be fairly stout.

However I would recommend a vertical support to the bracket that bolts through the upper part of the wheel well. That would support the bracket in multiple axis so dynamic loads like bouncing wouldn’t just leverage against those bolts on the horizontal part. Also the vertical wheel well sides are sloped so the tire could still sit against the bottom corner.

edit:
To clarify I would be thinking along the lines of 3-4 bolts spaced across most of the horizontal surface and 2 bolts on the vertical.

 

I cant get my SketchUp to load so I could draw it; however, what I'm thinking is a large X across the 2x6 bed pockets, bolting through them. You can see one on the wheel well of the picture above.

 

I get that-okay. So a vertical down the side at all four spots. Easy. Plates under-I missed that, but also makes sense.

 

Ah I got lost in my head before you talked about keeping the tire horizontal and using all 4 locations. In my head I was thinking about a Y shaped bracket mounted at one area holding the tire up vertical.

FYI my bumper and sliders bolted through unistrut washers, which should be about the right size for backer plates if you want something cheap and easy.