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NoCoast

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heymagic
Grant, there is nothing to be gained with your main hoop bend as shown. It doesn't gain any room over tilting the whole hoop back 3 degrees or so.

What about the more squareness of the connection of the half lateral to main hoop and rear stays? Not pictured yet in that drawing...

I don't see how putting a complex bend in there makes the 1/2 lateral joint more square. Looks like it makes it less square?

Not the direct connection. The one that's near your helmet that connects 12-15 inches or so outward of the junction.
And back to the rear stays.

Here's a good question for you tech inspection types.
Does the main hoop X have to be welded to the main hoop X? Or if you had a straight bar that ran longitudinally between the bottom of the main hoop, can the bottom of the X connect within 100 mm on that? Just trying to maximize the space in the upper X to potentially be able to fit a helmet through there.

Also, rules state 1.75 for main rollbar, lateral half rollbars, their connections, and at least one continuous door bar per side.
Their connections? Would that just be the windshield longitudinal member then?

Diagram on RA site shows the bar above the windshield as 1.75".

Blue is what I interpret can by 1.5" diameter. Rest is 1.75.

The lean back was just experimental. It does however move the main hoop H's intersection back almost three inches, which will be noticeable and give more room for the seat.
I just did some quick measurements on the Merkur to get used to the cage software. None of this is precise or being used to actually build anything.
Impreza cage design starts soon though.

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heymagic

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modernbeat
Once upon a time people didn't race because it was "dangerous". Now they don't race because it is "expensive".

Choose your poison. This season's wind blows towards the no-expense-spared in the name of safety direction.

Not buying into this statement at all. NO new expensive safety rules are in effect that I can think of. The basic cage design now (since 2007) is probably $60 more in materials than the previous minimum cage. Most cages are built beyond the minimum anyway. NRS and RA have worked diligently to keep the sport both safe and affordable. There are always compromises. The basic cost of a minimum spec build is still pretty affordable if done at home. The cost of insurance and roads keep going up, out of our control unfortunately. I can assure you that no sanctioning body or organizer is getting rich off of rally in the US.

Well, yes, you are correct. And I was speaking tongue in cheek. But safety cost HAVE gone up. Insurance (which replaces real safety in some places) has increased the cost of preparing a car, outfitting a driver/codriver, sanctioning fees, and is a possible reason for the increase of road closure fees.

Grant,
Your design is ok, main hoop bend no more than 10* rake backwards. The X bracing must attach on the actual hoop, not a cross bar.

Ok, listen guys, I HAVE AN X in my cage. Its very easy to pass a helmet through. My SEATS get in the way of doing it.


The X isn't the problem... it's the distance between and the width of your seats.

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NoCoast
Blue is what I interpret can by 1.5" diameter. Rest is 1.75.

The lean back was just experimental. It does however move the main hoop H's intersection back almost three inches, which will be noticeable and give more room for the seat.
I just did some quick measurements on the Merkur to get used to the cage software. None of this is precise or being used to actually build anything.
Impreza cage design starts soon though.

No sill bars? oh I see, just playing ,not final.



Edited 1 time(s). Last edit at 03/17/2011 04:21PM by alkun.

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Dazed_Driver
Ok, listen guys, I HAVE AN X in my cage. Its very easy to pass a helmet through. My SEATS get in the way of doing it.
The X isn't the problem... it's the distance between and the width of your seats.

Actually, in the two cars I've rode in, the X is the problem.

Sill bars aren't required. I did sill bars plus an X in my car though. I figure the more side protection the better. I actually like the sill and one diagonal style better.
And yeah, roughly based on quick Merkur measurements. Wanted to figure out software and what measurements I need to be exact on.

I agree with the sill bar. But a lot of WRC cages don't have them. I would think stump intrusion block is a good thing. Maybe for the fact that you take a tree stump and damage the sill bar, you're out? Didn't that happen to Gronholm at one rally?

The problem with my car is not the X, but the V in the rear stays. It pinches too much at the top and doesn't allow me to fit my helmet behind us. Kind of a bummer if you ask me. I would like to have have two helmets sitting in the co-driver's lap on transits.

I was thinking of helmet hooks, but i've heard of them bouncing up and cracking windshields at times too.

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NoCoast

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Dazed_Driver
Ok, listen guys, I HAVE AN X in my cage. Its very easy to pass a helmet through. My SEATS get in the way of doing it.
The X isn't the problem... it's the distance between and the width of your seats.

Actually, in the two cars I've rode in, the X is the problem.

Sill bars aren't required. I did sill bars plus an X in my car though. I figure the more side protection the better. I actually like the sill and one diagonal style better.
And yeah, roughly based on quick Merkur measurements. Wanted to figure out software and what measurements I need to be exact on.

Here is what we have done so far:

In the cars I've ridden in with an X, the problem isn't with getting the helmets through after you've taken them off, it's recovering them afterwards.

The X is really quite a PITA if you have a two-door.

Can you figure out a way to put the helmets in the trunk? Or is that space going to be taken up with a fuelcell and the spare?

Oh hey, wouldn't the main hoop lay back also make the X in the roof (it came about when the x in the roof was the thing to do) much wider, IE, more head room?

No.

hmm, I drew some lines, it looks like when you rake the main hoop back, and run the X to about 4 inches from the half laterals, and then run the little corner tube back from the roof bar to the half lateral, you actually DO get the most clearance. Now, obviously, it DOES depend on where you sit, but in general, that configuration DOES give the most room. That is the lime green line. It's a bit buried..