Rear seat mounts on roll cage

[bp71k5]

I'm looking for ideas on modifying my stock rear seat mounts and ran into an issue I wasn't confidant I knew the answer to.

I understand the concept behind attaching the seat to the cage along with the seat belts to keep everything as a single unit. But could there be issues with tieing the seat to the roll cage and the body at the same time?

Here's an illustration of what I was considering:


My existing cage is colored light gray and the rear seat bars I'm talking about adding are shown in green on each side of the bed. By running the bars like this I could keep a lot of flat bed space for storage, fabricate some rear seat quick-disconnect brackets (not shown) that included harness attachments.

But...I could use two of the stock rear seat mount holes in the bed as well. The smaller square green blocks on each side are about where the existing bolts go through. Are there any drawbacks to using both the existing mounting points along with the cage tie-in?

Feel free to criticize, suggest other options, whatever...

 

[rcamacho]

I've always wondered if it would add strength to run horizontal bars along the floor between the vertical tubes.

 

[bp71k5]

I've always wondered if it would add strength to run horizontal bars along the floor between the vertical tubes.

Well, it probably won't make it any weaker so it probably wouldn't hurt. I probably could run one across horizontally and still allow the seat to bolt down onto it. Then the seat along with that bar could be removed for hauling big stuff in the back.

I guess tieing it into more places on the body would only make it tougher to break away from the body. Maybe it's not as complicated as it seems.

 

[Greg72]

Brian,

That's a lot of extra tubing just to hold a seat down. I've seen it done that way plenty of times before but I have to wonder if there's an easier way?

How about a true "cradle" effect under the seat that links it to the rollcage over each wheelwell?? That's what I'm trying to imagine for my own setup... you can still do disconnects, but if they're near the wheeltubs they will be easier to reach and the cradlebars will be like handles you can use to lift the seat out completely when you don't need it.

Get creative and maybe you can somehow make that lift-out idea work as a couch for around the campfire at night??

 

[bp71k5]

How about a true "cradle" effect under the seat that links it to the rollcage over each wheelwell??

That's would work fine, but would you tie it into the cage on just the left and right side? Those bars were an attempt to add more rigidity front to back, but maybe I'm thinking too much overkill. Although, I could run two cradle type bars across instead of just one. Hmm.

Get creative and maybe you can somehow make that lift-out idea work as a couch for around the campfire at night??

Nice idea!

 

[Greg72]

That's would work fine, but would you tie it into the cage on just the left and right side? Those bars were an attempt to add more rigidity front to back, but maybe I'm thinking too much overkill.

Keep in mind how the factory did it....only 4 bolts in the rear with a backing plate under a thin sheetmetal floor, and two tiny clamps on the front. There's overkill, and then there's OVERKILL... it won't take much to build a superior mount to the factory one.

Rememer the real loads are on the rear seat mounts in a crash, so that's where to concentrate your efforts...

 

[bp71k5]

Makes sense. Would you be afraid of using any of those 4 factory holes in addition to the cage tie in's? That was one of my early concerns.

 

[Greg72]

Not really concerned...they would just make it less of a "quick disconnect" system if you have to unthread a bunch of floor bolts.

Think about ditching the factory rear standoffs and coming up with your own tubing back there, that might make things easier....or at least stimulate the creativity some more.

 

[ktmoutfront]

Maybe also run a bar from side to side in front an at the back of the seat. These could be tied to the original mounting holes, then the seat to them. I did that and mounted 2 PRP roadster seats. They a extremely solid.

 

[rdn2blazer]

I am going to be mounting my Mastercraft rear bench here in the next weekend or two. I am taking into consideration hear clearence. My cage fits as tightly against my hard top as possible. It does slope down towards the back but not a great deal. I feel mounting my rear seat on top of a tube or tubes with tabs will make the seat way way to high for anyone but a child. An adult will not be able to sit back there safely in a roll over with the seat mounted on tube. For this reason I have decided to mount my seat on a plate thats tied into the cage but sits directly on the floor of the truck.

I sat in the seat just sitting on the plate and it must have some tilt backwards to be comfortable, thats fine. The back edge of the seat frame will basically be touching or as near touching the plate as possible. I estimate about a 4" to 6" max height under the front of the seat. This tilts the seat to a very comfortable posistion IMHO, atleast for me. So I have to build Right angle brackets like a right angle triangle. The plate they will mount to is a piece of 3/16 thick steel. I plan on making some cut outs, or some fairly large holes in stratigic locations to lighten it up somewhat. The plate currently is bolted to the floor of the truck using the factory seat mounting points. Thats where it will mount but it will have cage tubing drop down from the side rails of the cage that land at the four corners of the plate.

I also want to bed floor to be as flat as possible IF for some reason I want/need to sleep in the back using an air matress or sleeping pad. I will be counter sinking the plate and using 1/2-13 Zink plated Flat head fasteners, a actually ordered those today from McmasterCarr. I'm making the seat a Quick realease setup but it will not come loose during a rollover. I want to seat to be able to be removed easily when I have to pull it out. This is still in a design stage but basically I have it all figured out what I want to do. Wish I had some fancy CAD drawings for ya but I don't.