roll cage mounts?

[hopefulcj]

For those of you that have full front roll cages, where did you mount the "foundation" of the roll cage? to the body? to the frame? i have seen people mount full tubular roll cages with seats mounted to the roll cage and I have seen people mount roll cages to the frame? which is safest? the seats are mounted to the body so protect the body, or mount the cage to the frame and hope the body says put? whats the safest and most economical way to mount a safe cage?


something along the lines of the cage in the pic?

Thanks guys, Jacob

 

[mylittlecj5]

The safest way to mount it would be go thru the body to the frame, using bushings on the tie-ins. But that can decrease flex (if you need it for your style wheeling).

 

[Old Dog]

My cage is mounted to the frame, and the seat brackets are part of the cage.

 

[Purple77CJ7]

I used these brackets from M.O.R.E. to tie the front hoop to the frame.
WCK101 Frame Tie in kit for CJ & YJ

 

[Manhattan]

Talk to your fabricator about "cage stakes". There are a couple of ways to mount a cage to the body/frame...
1. Cage has square feet and bolts to body: Purely for show, offers very little protection
2. Same as no.1 but the plate under the body is welded/bolted to frame via "out riggers" - tubes extending from frame: MUCH better than above - very strong, but does not allow for any body/frame flex. This design has an inherent problem... explained below.
3. Same as no.2 but integrates a joint and bushing in the outrigger - retains strength of cage AND allows for body/frame flex. This design has the same inherent problem as no.2.

Okay, that inherent problem. The typical design uses two 4"-6" plates (per pillar) to sandwich the body/floor. Plate A is welded to the cage. Plate B is welded to the outrigger. The two plates are bolted together with 4 grade 8 bolts.

This ^ does make for a VERY strong cage. You could swing the Jeep around (big crane) for days like this. But it does rely completely on the shear strength of those bolts. All that HREW or DOM tubing is out of the equation at the point where the cage is attached to the frame.

Cage stakes solve this. They're sold by fabrication suppliers. Picture a plate with a large nipple - that nipple's O.D. is the I.D. of the cage tubing. The top plate welds to the pillar and has a large hole in the center. It bolts to lower plate (under the body) via 4 bolts. The lower plate has that nipple. The nipple goes through the body (yep, 5th hole - the size of the tubing I.D.) and INTO the cage/pillar. Now the shear load is taken by the tubing (and the welds) NOT the bolts.

When the fabricator who built my cage explained it to me, it seemed like overkill. And it probably is in most cases - mine included. We rationalized that the impact that would shear 4 grade 8 bolts was not going to happen in a 3 mph rollover on the trail. it was going to happen at an intersection on the street. And, the cage stakes are an insignificant cost in the big scheme of building a cage.

 

[JR74CJ5]

i was going to try to fab something like this up myself, or the above linked one...

TJ Roll Cage | Roll bar | Jeep Parts | Jeep Accessories | Jeep Bumpers | Jeep Gas Tanks

I know it says TJ above, but when you look at it says CJ too on the page

anther forum, but some good options (when they get done arguing... love this "jeep-cj" forum): Roll cage frame tie in ??? - JeepForum.com

all these just from a quick google search: https://www.google.com/search?source=ig&hl=en&rlz=&q=Roll+Cage+stakes&oq=Roll+Cage+stakes&aq=f&aqi=&aql=&gs_sm=e&gs_upl=191l9171l0l9315l23l23l6l3l1l0l190l1711l4.10l14l0#pq=jeep+roll+cage+stakes&hl=en&sugexp=lttmo%2Cn%3D230&cp=18&gs_id=8p&xhr=t&q=jeep+roll+cage+tie+in&tok=sCC6k9yM5SvaCu00RgEuqg&pf=p&sclient=psy-ab&source=hp&pbx=1&oq=jeep+Roll+Cage+Tie&aq=0v&aqi=g-v1&aql=&gs_sm=&gs_upl=&bav=on.2,or.r_gc.r_pw.,cf.osb&fp=bacf1ad0836eaa60&biw=1280&bih=817

Searched for "Jeep roll cage tie in"



~ JR

 

[Old Dog]

Manhattan, great idea with the cage stakes.

 

[BajaEdition]

I have experience with a roll cage having saved my life
flipped a jeep at 75 and rolled down the freeway, doing about 125 yards upside down in a slide before it stopped

first, safety belts are way under rated, factory retractable belts are worth their weight in gold

second, a roll cage needs to be mounted to 8 points, 2 in the rear of the jeep, 2 behind the seats, 2 on the top 2 corners of the windshield and 2 either to the dash or the floor board in the front.

I can say the guys who are saying to the frame is better, but good solid to the floor saved my life

and that windshield mount, saved it to, the frame of the windshield was wrapped around the upper cage, without that it would have collapsed on me and that would have taken out my neck

bolted is nice, welded is better

but a full cage saved my life, if I had only had the factory cage, I would have been ground beef.

Jim

 

[AussieCJ7]

Most race car associations around the world only specify body mounted cages with sandwich plates the size of these plates is normally specified by vehicle weight and cage tube size

as long as the top plate is different size to the bottom plate you eliminate most of the "tearing" of the body sheet metal and if the body is sound then you looking for failure at 4 to 6 points for this style to be an issue


One thing to think about Never have the Belts and seats mounted to different structures eg belts to cage an seats to body if you do get them separating you run the chance of being cut/compressed by the belts

Here is the specs/ rules of our local 4x4 competition ruling association gives you some good guides on tube size and thicknesses

http://www.ccda4wd.com.au/images/RolloverProtectionDrawingMaster060428.pdf