Outer Limits 4x4 Board

Just wanting opinions on what people think is a stronger design for the B-pillar cross bracing on a 6 point cage for a zook. It will have a harness bar and the b-pillar hoop will be fairly think-something around 50mm OD with good wall thickness. Do you think it would be stronger to have 2 diagonal cross braces like this:


or just a single bar like the pic below. It has been suggested to me that this design is better as your not welding to other main diagonal bar which would only weaken it and the thickness of the b-pillar hoop would be more than adequate.


I would like the opinions of anyone in the know of what would be stronger as i want this cage to be strong to save doing things twice. Thanks in advance

John.

The single diagonal according to CCDA is adequate enough. I'm not sure if adding the second diagonal would weaken it. If you are going to do it properly use 48.3 OD seamless for strength.

LudaCris

2 cross bars will be far stronger, Is it needed well i dont know how u drive, but like u said u dont want to do things twice.

Look at rally cars, I belive they have to have the best cages in the world because of the speeds they travel down narrow roads with either trees or cliffs either side. They are crossed behind u like the first pic, crossed on the roof, and thoses 2 bars that head out the back are also crossed. Who ever told u another cross bar would weaken it, is a dipshite

just a minor thing with the single cross brace when fitting /building it

is to have it run from the top of the passenser side to the drivers bottom side

mine was built buy a shop and it goes the opposite way ,and the bar does create a blind spot when your trying to look back when going backwards

Id have it from driver side dowm as that is where you are sitting

2 cross bars would be stronger,just make sure that the cross bar behind drivers and passengers seat that supports racing harness seat belt as it come through the seat is level with the eyes in the seat (the black zook's looks to low)as it would put huge pressure on seat back and your back in rollover.

i agree with rhett... im doing mine from drivers down to passanger, just incase. john you dont NEED a cage as u dont drive hard enough or anywhere difficult enough to roll it....as you seem to want one so much you may aswell get the two as you said yourself, dont want to do things twice.

What happens when it rolls on passenger side? which either way you bace the main hoop it it shouldent matter,it will still stop it from folding.

thanks for the input guys..much appreciated. Will definitely be putting the harness bar higher than on the black zook and plowy...wouldnt it be harder to see out the back with the bar running from top of pass to bottom of driver?

As far as "not needing a cage" ev, you don't have to be driving hard or fast to roll. Anyway if i ever decide to enter any timed comps in the future at LCMP im goin to need one and i may as well have one just for safety in the mean time....also be an advantage onroad coz who really wants to hit a roo or something at 100km/h when ur only surrounded by al-foil and glad wrap? (soft top zook) not me!

i told this to modified toy and made them aware or it when building theres
and the vision in theres is alot better compared to mine

its the part of the bar on mine were it comes down behind the seat that blocks the rearward vision
when you spin round to look behind you get a face full of roll bar n padding

as to wich way the diagonal goes what is the difference ?

the brace is to give the cage strength in a roll over to stop it from loosing shape correct ?

but on that not it probably be better to have bouble cross braceing to keep its strength on a left or right roll over

plowy wrote:

as to wich way the diagonal goes what is the difference ?

but on that not it probably be better to have bouble cross braceing to keep its strength on a left or right roll over

U just answered your own Q

driver top to passenger bottom, second will not weken but add more strenght although with the speeds you are doing the single is strong enough to do the job.

put the harness bar a little lower then the position the harness will exit the back of the seat, to low will end up crushing your shoulders in the even of a decent roll over.

make sure you run two front legs / hoops thar run along the roof line and down follwing the profile of the window and firewall and run a removable spreader from each side of the a pillars as you are supposed to be able to remove this section for road use.

also can be benaficial to mage the rear legs removable as dont have to re engineer as a two seater

Tiny wrote:make sure you run two front legs / hoops thar run along the roof line and down follwing the profile of the window and firewall and run a removable spreader from each side of the a pillars as you are supposed to be able to remove this section for road use.

According to CCDA or RTA?

Gribble wrote:

Tiny wrote:make sure you run two front legs / hoops thar run along the roof line and down follwing the profile of the window and firewall and run a removable spreader from each side of the a pillars as you are supposed to be able to remove this section for road use.

According to CCDA or RTA?

RTA, CCDA DGAF, as long as it meets there specs and the vehicle registered as required for the given class

While you're building a cage you may as well fit the 2nd cross brace. You may not drive difficult &/or high speed terrain now but you may do in the future.

Just be sure to attach the cage to the chassis and not only to the body. In a zook where space is tight a roll that moves the body slightly (thats what your seats are attached to) may cause the cage to impact on the vehicles occupants.

thanks again for the all advice guys....yeh i believe i cant legally run a dash spreader bar on the road according to RTA so removable is probably the go. Its already registered as a 2 seater coz already got defect from qld trans for not having back seats among other things so this isnt a prob.

Only other question is how do people go about mounting their harness bar at the right height when running double cross brace because wouldnt the only strong place to weld the harness bar in be as the intersection of the two diagonal braces? What if this doesnt line up in the right spot with the seats?

John

Nev wrote:
Only other question is how do people go about mounting their harness bar at the right height when running double cross brace because wouldnt the only strong place to weld the harness bar in be as the intersection of the two diagonal braces? What if this doesnt line up in the right spot with the seats?

John

You will need to run a bar horizontaly to mount the harnesses to in addition to the diagonal cross braces.

You curve the horozontal bar back at each end to clear the braces
J Top

I just run a double bar one for the cross brace and one for the racing harness one at the top of the seat for the belt to run over and one at the bottom of the seat for the harness to anchor to.

or you can run rear anchored harnesses like I have. In my shorty zook they run to the existing rear seat belt bolts.

Awesome think i should be able to sort something out from all those opinions. thanks again.

sierrajim wrote:Just be sure to attach the cage to the chassis and not only to the body. In a zook where space is tight a roll that moves the body slightly (thats what your seats are attached to) may cause the cage to impact on the vehicles occupants.

I was just going to run large foot plates with a plate underneath to strengthen it when I make the cage for my zook.
So you reckon I shuold atach to the chassi?
How do I do that? Isnt the cab rubber mounted and moves a bit in relation to the chassi?

ausyota wrote:

sierrajim wrote:Just be sure to attach the cage to the chassis and not only to the body. In a zook where space is tight a roll that moves the body slightly (thats what your seats are attached to) may cause the cage to impact on the vehicles occupants.

I was just going to run large foot plates with a plate underneath to strengthen it when I make the cage for my zook.
So you reckon I shuold atach to the chassi?
How do I do that? Isnt the cab rubber mounted and moves a bit in relation to the chassi?

punch holes in teh cab where you want the rolcage to go through to the chassis, make them a little larger than the pipe OD so you can cut a rubber ring around the pipe to seal it. to shop mut dirt water and vibrations,

JEs

So what do others do on a SWB Zook when the B pillar hoops mounts onto the front of the wheel arch?

I would have thought with a big enough ( not excessive) base plate the stress would be spread over enough area to make mounting to the body viable. If I do this which plate should be bigger, the one above the body panel with rollbar mounted to it or the one under the bady panel. I am lead to believe they should be the same size.

Nev wrote:Only other question is how do people go about mounting their harness bar at the right height when running double cross brace because wouldnt the only strong place to weld the harness bar in be as the intersection of the two diagonal braces? What if this doesnt line up in the right spot with the seats?
John

They don’t need to line up, For u to pull the bars out that your seat belt attaches to u will…..well......U just couldn’t, your body would fly to bits from the G forces before that happened. Look at how your seatbelts are attached now, a small 12mm?? nut pressed into some tin, have u ever heard of seatbelt mounts breaking in a accident?? I haven’t.

ausyota wrote: I was just going to run large foot plates with a plate underneath to strengthen it when I make the cage for my zook.
So you reckon I shuold atach to the chassi?
How do I do that? Isnt the cab rubber mounted and moves a bit in relation to the chassi?

I believe a 6 point cage with large foot plates in a road car would be enough to support the weight of a little zuk in a rollover, U can look at it in another way aswell, If u mount the cage to the chassie u should also mount the seats to the cage, if not, if the body brakes loose u get squashed between the floor of the body and the roof of your cage, where do u stop on a daily driver???

ausyota wrote:

sierrajim wrote:Just be sure to attach the cage to the chassis and not only to the body. In a zook where space is tight a roll that moves the body slightly (thats what your seats are attached to) may cause the cage to impact on the vehicles occupants.

I was just going to run large foot plates with a plate underneath to strengthen it when I make the cage for my zook.
So you reckon I shuold atach to the chassi?
How do I do that? Isnt the cab rubber mounted and moves a bit in relation to the chassi?

It is illegal to attach you roll cage to the chassis, you must attach it to the floor pan of the body using 100 x 100 plate. reason being that if in a sever roll over and the cab becomes detached from the chassis then you will still be protected by the cage. And it does happen look at Norm Walters and Kym Bolton at 2005 OutBack Challange after a roll over most of their body mounts had broken and they had to finish the challange using ratchet staps to hold the cab.

I had a look at Col's cage on the weekend (black zook-top pic), must say, it held up very well after his flippin good weekend ...
Safety wise for the speed he does, the overkill is understandable but unless you are pulling the same amount of power/speed , i think a 'tamer' cage would be more than enough.

Mine has the b pillar, top sides, crossbar, twin diagonals (star), side intrusions and across the dash mainly so it doesn't have to get done twice

ps...but only when i get the exo on will i feel safe, would be heartbreaking to fawk the bodywork now