Installing 5 point harnesses

Down&Dirty

Well-Known Member
Joined
Jun 26, 2005
Location
Greenville SC
So I finally broke down and ordered some harnesses for the trail rig. Now I have been trying to figure out how to install them. I have looked at the simpson site and seen the recommendations on angles to pull the straps, but I don't have the bar for the shoulder straps that falls into that range. I have read all about people saying that you will hurt your back if you don't use those numbers. If this is true, why do places sell setups that will reach the floor? I understand that if I was ever going to drive this thing on the street I would want the harness to be setup correctly, but for rock crawling am I really risking more back problems? Basically I have the Summit plastic seats, then the X on the cage behind them. This puts my shoulder straps leaving out the back of the seat and then needing to go down at 2 different angles. About 20 degrees for one side and 30-40 degrees for the other. Is this setup risking more back problems then I already have?
 
just run a bar from the center of the "X" over to the uprights on the pillar.

Sure its added weight, but ya really don't want to fawk with the proper mounting position of the harness.

Remember, a harness installed incorrectly can be worse than no harness at all.

Rob
 
technicaly, they should be IIRC about 6" below your shoulders, but remember your not taking an impact at 100+ mph. You can safely run them to the floor - just dont run them at a 90*, space them back from the seat a hair.
 
One related question. If you have the style seat that has holes for the shoulder and lap belts, wouldn't that negate the need for a proper mounting angle? The holes in the seats should take care of locating the harness in relation to your shoulders and hips, and the angle of the strap behind it wouldn't seem to matter.
 
its not locating the harness on the seat thats the issue, the mounting points the harness' run to determine the restraining force the harness transfers on you when you get tossed forward.
 
Alright, I mocked it all up tonight. If I try to run the bar across the X then the belts are 4 inches to long to tighten up. I can run them at a 45 degree angle out of the seat. This pulls them about 6 inches back and 6 inches down from the openings in the seat. About 7 inches below my shoulders. With the mounting tabs it will pull the mount up a little reducing this angle. This will be for rollover protection only. I don't think I can get this rig up to 100 without finding a tree around 30. I just really don't want to screw this up and put myself at more risk then without the shoulders. I think that with the mounting tabs I will end up between 35-40 degrees out of the back of the seat and just the right length. And I am 6'5" so that will probably be the tallest person in the rig.
 
catfishblues said:
One related question. If you have the style seat that has holes for the shoulder and lap belts, wouldn't that negate the need for a proper mounting angle? The holes in the seats should take care of locating the harness in relation to your shoulders and hips, and the angle of the strap behind it wouldn't seem to matter.
Click to expand...

Not totally. You don't want the belts trying to compress the seat back as well.. it can and has caused seat failure when the belts were mounted at too steep of an angle.

Basically, you want it so that when the straps are VERY tight, like in a roll, that the shoulder belts will not deflect up, allowing you to move up.. That's where that 6"-ish below your shoulder number comes from.

Look at this pic in full-size and you can get an idea of where mine are.. http://www.rnrfab.com/rich/fj/dpg10-05/images/10_jpg.jpg

And I will agree with Nuts.. you CAN run them to the floor, if that mounting point is far enough back to not put too much downward force on the seat, but it would really kill the functionality of that area back there.
 
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