Questions about roll cages

[Mr Revhead]

I got a half cage, really was to strengthen up the rear end as the rear flexed ALOT that i couldn't even open the boot after a run. The half cage def fixed that issue.

now where is the load transferred to?

Whats your point?
Where is the load transferred to in any roll cage lol.

If you have a whole heap of flex in one area, and you solve it by fitting a half cage, you have to be careful you dont concentrate all that flex to one or two smaller points in the car.

[Bazda]

I got a half cage, really was to strengthen up the rear end as the rear flexed ALOT that i couldn't even open the boot after a run. The half cage def fixed that issue.

now where is the load transferred to?

Whats your point?
Where is the load transferred to in any roll cage lol.

If you have a whole heap of flex in one area, and you solve it by fitting a half cage, you have to be careful you dont concentrate all that flex to one or two smaller points in the car.

I did it for 3 reasons, to fix the rear end up, provide some safety, eventually make it into a full cage later. .

The load is now being transferred to the roll cage. As the suspension rear towers are welded to the cage bars. I think it will def be strong enough to not effect anything else. Its just like making a strut brace to stop the front towers from moving. Similar thing but the roll cage fixed it not a normal style strut brace.

[Mr Revhead]

Oh yeah for sure, I was thinking the flex would be between the strut towers. So you have basically built an uber strut brace. No issues there then.
I was just wondering that if your flexing issues where in other areas/directions there could be problems.
I have heard of cars with stiff cages to a point developing cracks and the weaker uncaged sections as all the twist that usually goes along the length of the chassis is concentrated in a smaller area.

How that would apply to a half cage could be say you have made a really stiff rear structure tying into the top of the pillares, struts and floor etc stiffening the whole rear of the car. Potentially in some cars that could cause an issue. Also probably highly dependant on the use of the car as well

[d1 mule]

it doesnt have to be done by a certified welder, but on the homologation form its got like a occupation/qualifications on the welder section

[Truenotch]

The certifier looks at the heat signature on the bare metal and decides if it has enough penetration to be strong. No welding ticket required, but it helps.

[Leon]

You can add front stays and side intrusion to a half cage, no problem. To do this you have to make it to the right specs and get a "homologation extension". This basically consists of re-drawing the cage design to the new specs, getting the engineer to fill in a form and having MSNZ sign it off.

very minor correction, essentially you're 90% right. It is no problem to change from a half to a full cage. But it's not done through an extension, it is done through a new homologation. Really only a paperwork difference though, your main point is totally correct.

If you're doing stuff like adding or changing intrusion bars to a cage, or some diagonal brace bars or such, then it is done through an extension. But when you're altering the principle structure design, then it's a fresh homologation.

Full cage in a daily driver is a nightmare. You duck and bend every time you get in and out of the car, and you have to adjust the belts every time. Reversing in belts is a prick. You wear out your belts super fast too. I've seen a set of FIA Silvester belts (two sets actually) completely poked in the shoulder straps in slightly over a year. Just because they didn't like that many adjustments (every time he sat in the car).

[B1NZ]

Full cage in a daily driver is a nightmare. You duck and bend every time you get in and out of the car, and you have to adjust the belts every time. Reversing in belts is a prick.

2nded, 3rded, 4thed, 5thed etc.... When our car had been off the road for a while I though before the next event I would give it a bit of a run so used it over a weekend to go everywhere, Never again, it's so annoying, it's exceptionally great when you park in a car park and someone parks too close to your door and you need to open the door a certain distance to actually squeeze under and over the bars

[CAMB01]

I have yet to get it certed or homologated. But will be doing that later this year.

How did you do Superlap if you dont have homologation?
Or is there an exception?

[rollaholic]

i thought cars only had to be road legal to enter superlap

[CAMB01]

I believe they still have to meet clubsport basic rules.

[DRFTIN]

yeah a car might be road legal but if it has any form of cage is has to be homologated to run in a MSNZ event
i think theres a clause to get away with this for basic events at the scrutineers discretion but it wont count for super lap i doubt

[Distrb]

I have yet to get it certed or homologated. But will be doing that later this year.

How did you do Superlap if you dont have homologation?
Or is there an exception?

According to his build, he didnt have the half cage done by superlap, so wasn't an issue.

[Bazda]

No cage for superlap. I put it in later.

As for running a 'half' cage it just has to have a cert. If its homologated then you have to enter the Pro street class. If its just certed the street class. If you have both I guess you can choose lol.

[CAMB01]

Ah yep my bad

[Santa'sBoostinSleigh]

Full cage in a daily driver is a nightmare. You duck and bend every time you get in and out of the car, and you have to adjust the belts every time. Reversing in belts is a prick.

2nded, 3rded, 4thed, 5thed etc.... When our car had been off the road for a while I though before the next event I would give it a bit of a run so used it over a weekend to go everywhere, Never again, it's so annoying, it's exceptionally great when you park in a car park and someone parks too close to your door and you need to open the door a certain distance to actually squeeze YOUR FAT ARSE under and over the bars

yeah, who ate all the pies?

[cat007]

I think I'll go with a half cage at present - as long as they make it so the harness bar can be taken out - and the whole thing can be extended and made into a full cage at a later date, if I so choose to do so.

[KE25-KP30]

I was under the impression that any cage needed cert, and in the cert booklet that says you dont, it's talking about rollover bars you see on the likes of MX5's and such.

Has anyone actually got a WOF with an un-certed half cage?

[pc]

I was under the impression that any cage needed cert, and in the cert booklet that says you dont, it's talking about rollover bars you see on the likes of MX5's and such.

Has anyone actually got a WOF with an un-certed half cage?

Nope, MSNZ homologated cages need a valid MSNZ authority card to get a WOF. No LVV cert required.

[Rick]

No LVV cert required.

Correct.

[KE25-KP30]

Really!? That's cool!

So what we're saying is that a half cage will go through a WOF with no problems? So long as what? You can't hit your head on any part of the cage no matter how hard you try?