I am about to weld some strengthening plates to the Moke for the roll cage.

The question is: should the plates be larger than the size of the feet of the roll cage or the same size?

I've just gone down and had a look at my moke and there doesn't seem to be any strengthening for the roll cage (81 californian , factory fitted half cage) although the bar that holds the seatbelts does bolt onto the panel where it meets a vertical divider so would be strong . Just for peace of mind though , maybe make the plates a bit larger than the feet but that's probably just personal preference on my part .

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My weld-in cage has, from the top: cage tubing, 6mm thick foot plates about 100mm square then 2mm spreader plates that are welded around the outside and plug welded in multiple spots to teh top of the side of the car. These 2mm plates are the full width of the moke side and square.

I recommend this approach because it will prevent the foot plates from punching through the moke panels in an impact and also adds considerable rigidity.

Some people have criticised this saying that the cage should go to the floor, not the top of the sides. These people obviously don't have any knowledge of momentum and load paths, so they get ignored.

M

My one is the type that bolts to the floor. What concerns is that the floor would not take load in that direction as it is an untressed element.



So what do you reckon of a full width of the side on the back and a thick lump running from the floor tunnel to the side, runnoing up the side about 3 cm? Overkill?

Waaay overkill

I just looked up my engineers report for the AWDmoke roll bar.

Paraphrasing Code of Practice 105A Section 4 (vehicles under 1150kg)



But remember, mokes came out with "seat belt mounting bars" not roll cages

Hope that helps.

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Too many cars, and too little time.

Since it's bolting to the floor I'd say what you're planning sounds alright , mine bolts to the top of the side pods so is a fairly strong area , it bolts onto the top but closest to the inside vertical edge and right behind a vertical divider inside each side pod so is braced on two sides and the outside edge isn't far away either . Remember , if anything happens and you do roll it (unlikely but anythings possible) , it's not like a conventional car , there's nothing really to stop it landing flat from the top of the firewall (windscreen's not much support) to the rear panel , reinforcing the floor sounds a good idea .

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What I have gone for is a top piece that is 20% larger than the foot of the roll cage (I mean seat belt hanger) and a piece under the car that is 40% bigger than the foot. Both the top and bottom pierce is 2mm steel.

That makes the top 170x100x2mm and the bottom approx 210 x 120 x 2mm.

I have cut it up, but as usual I am out of Mig wire. Dont you hate that!

Tomorrow I turn it over and finish stripping the bottom, then its painting time. Yippeee

[quote="awdmoke"]Waaay overkill
[/quote]

The thing that concerns me with these roll hoops is the floor mounting.

Just think what the weight of the car (plus inertia) might do.....those small mounting pads could easily punch through the floor under the right circumstances.

But....if it were me, I would be looking at reinforcing and load spreading plates under the floor.

Best idea is to not roll at all!!!

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"Show me the Mini!"

I need it to be CAMs compliant. It has to be a roll cage not just a seat belt hanger.

[quote="Blokeinamoke"][quote="9YaTaH"][quote="awdmoke"]Waaay overkill
[/quote]

Best idea is to not roll at all!!![/quote]

I need it to be CAMs compliant. It has to be a roll cage not just a seat belt hanger.[/quote]

Well maybe you should beg borrow or something else a recent CAMS Manual of Motorsport and look at the guidelines first....then have a chat to a Scrute

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"Show me the Mini!"

The best cages don't have any unnecessary bends. Yours has bends in the main hoop and the rear legs. I think you'll find that these don't comply with the CAMS rules.

Here are some pics of Mokesta's cage. The main hoop is a bit too high because it was designed for the correct above head clearance with the seats mounted higher. I wanted a diagonal in above my head but I couldn't have it with the head clearance as it was. Maybe it would be ok now.


Note the reinforcing under the main hoop base plates in this pic and the sturdy seat belt mounts. There are welded in threads for harness eyes that can't be seen from here.


The cross tube under the dash is welded to the the body where the engine steadys attach. These weak areas on the moke always crack and my passenger side one has been reinforced with 2mm plate.


Windscreen frame to dash bar to side intrusion bar to body join.


Long bends in main and windscreen hoops look bad but are much stronger than tight radius bends. There is a bar across behind the seats and another between rear shock mounts. Makes the load area pretty useless.


You could throw a strap around any node on this cage and pick the car up no problems.
It is not the lightest cage at about 32 kg plus base plates and not the most torsionally rigid, with no roof or windscreen diagonal or corner gussets. But it is a thousand times better than the standard cosmetic thing.

M.