Author Topic: Cage/Helmet Clearance  (Read 205 times)

Offline lake_harley

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Cage/Helmet Clearance
« on: September 15, 2022, 07:17:08 PM »
Started constructing and planning the roll cage for my FED. Driver was here today and we mocked it up with him in the car, helmet on, with 2" of clearance over the top of his helmet. To that we added the thickness of SFI padding to be installed. Called S&W race cars where I bought my chassis plans and talked to a tech. He said there's no actual minimum but to have enough clearance for some head movement, and not so tight to hamper doing a quick get-out in an emergency. So, am I on the right track with 2" between the helmet and the roll bar padding? It seemed to me that too much clearance would be as bad as not enough.

I'll appreciate thoughts.

Lynn

Offline tcoupekyle

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Re: Cage/Helmet Clearance
« Reply #1 on: September 16, 2022, 07:38:17 AM »
I don’t know but…. I have about 1inch between my helmet and pads in mine and it seems to be fine

Offline tcoupekyle

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Re: Cage/Helmet Clearance
« Reply #2 on: September 16, 2022, 07:41:12 AM »
It looks like more in these pics but my helmet will touch the padding pretty easily if I move around.

https://photos.app.goo.gl/k7mFA2SeYw8PLmsD6

Offline lake_harley

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Re: Cage/Helmet Clearance
« Reply #3 on: September 16, 2022, 10:54:49 AM »
Thanks for the replies. Based your examples of closer fitting cages, I might "tighten up" my cage a bit. Your examples verify what the tech at S&W had to say.

I can't stand the looks of a big tall, gangly-looking cage, but certainly didn't want to compromise safety by thinking too much about only looks. My driver is a tick over 6' but I'm only about 5'9". In talking it turns out both of us wear 34" inseam pants so his extra 3" of height is mostly in his torso which made sense considering the headroom I had sitting in the car. When I sat in the car with the rear cage tube mocked up I had a GOB of headroom and would have looked like a gnome sitting in it.

Thanks gents. Now I have some info the move on in an informed way.

Lynn

Offline wideopen231

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Re: Cage/Helmet Clearance
« Reply #4 on: September 16, 2022, 12:09:45 PM »
You want to fit comfortably,but not loose. When checking it is best to have full suit on.It make huge difference.
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot

Offline janjon

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Re: Cage/Helmet Clearance
« Reply #5 on: September 21, 2022, 09:17:54 AM »
Should harness stretch on impact be a consideration?
Just keep the same amount of stuff on the right
as there is on the left. Seeing straight ahead is highly overrated....

Offline wideopen231

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Re: Cage/Helmet Clearance
« Reply #6 on: September 21, 2022, 03:07:59 PM »
As tight as we have belts that should be nothing. Now if you wear them loose tighten them .
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot

Offline fuel749

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Re: Cage/Helmet Clearance
« Reply #7 on: September 21, 2022, 03:47:00 PM »
Started constructing and planning the roll cage for my FED. Driver was here today and we mocked it up with him in the car, helmet on, with 2" of clearance over the top of his helmet. To that we added the thickness of SFI padding to be installed. Called S&W race cars where I bought my chassis plans and talked to a tech. He said there's no actual minimum but to have enough clearance for some head movement, and not so tight to hamper doing a quick get-out in an emergency. So, am I on the right track with 2" between the helmet and the roll bar padding? It seemed to me that too much clearance would be as bad as not enough.

I'll appreciate thoughts.

Lynn

There is an actual minimum listed in the SFI spec.  Either 2 or 3 inches I can't remember and it doesn't really seem to be enforced

Offline JEFF/21C

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Re: Cage/Helmet Clearance
« Reply #8 on: September 22, 2022, 07:16:56 AM »
Always make sure your belts are tight, I've seen people hurt when they flipped and belts were not tight enough.you should set-up your cockpit with all your safety equipment on, street clothes are not the same!

Offline Supercat

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Re: Cage/Helmet Clearance
« Reply #9 on: September 22, 2022, 07:34:47 AM »
If you are planning to do a seat pour(foam) take that in as part of your measurements.

Offline lake_harley

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Re: Cage/Helmet Clearance
« Reply #10 on: September 22, 2022, 05:02:46 PM »
Did a 2nd fitment today with the driver wearing a driving suit (3 layer Sparco) over jeans. Decided to shorten the back "spine" tube of the 5-point cage by 1/2" which will leave 1"-1 1/2" clearance after allowing for the thickness of SFI roll bar padding.

I am going to bend a different spine tube with a bit tighter radius which will allow a longer tube between the front and rear hoops without the cage sticking W-A-Y forward of his helmet. With the rear tube I had the connector between front and rear hoops would have only been maybe 2" long. Leaning the rear hoop back a bit further by having a tighter bend radius on it will also put the rear hoop in a better position, like more out directly to the side of his helmet. I plan to have the front of the front hoop 3-4" out from the front of the helmet, measuring at about the top of the visor opening. I think I read somewhere in regulations that 3" is a minimum, and I believe that was to the front of the front hoop.

If you read anything wrong into what I have tried to describe, please call me out on it and correct me. I want to do this right. To me, it's the most important part of the whole chassis.

Lynn