Harness and head and neck support

[BlueBDA]

For this season I have bought a new helmet (Snell 2020) and this head and neck support:

 

https://www.schroth.com/en/segments/racing/products/details/show/id-20-shr-evo-medium.html

 

I just tried them out in the seven. I tightened the shoulder belts as tight as I could, and I was surprised at how easy it was to move the shoulder belts around on the HANS (ok - this one is an "SHR"), especially on my right side. I could shift the right belt further to the right, so it was no longer centered on the SHR. Then I realized that the belt mounts are not centered with the seat (see pics).

 

Belt mounts and seat position are standard Caterham S3, so I am guessing that others have encountered this? Advice?

 

 

 

 

[Croc]

 

 

Yes it is a well known problem with Caterham and Hans.  I have seen people live with it but not sure I like that idea.  Two options to address:

1) Move belt mounting locations to fit Hans.

2) Using a Tillet seat where the shoulder belts pass through the holes tightens up how the belts can move across the shoulder such that you do not need to change the belt mounting holes.  

 

[FE07]

I use a HANS and had the same concerns in my car.  I fabricated the adapter below to change the mounting points for the harnesses.  The gold bolts mount the adapter into the existing holes for the harnesses so it's solidly mounted to the car.  There are 2 steel plates so that the shoulder straps are mounted between them in double shear.  Some spacers between the steel to space them out so the straps have a little wiggle room to rotate.  Just be careful that the harnesses don't go onto your shoulders from more than about a 20 degree angle from horizontal from the adapter.  If you're tall- the harnesses could compress your spine in an accident. (although they'd still save your neck with the HNR!)  I'm 5'7"- works for me.

 

(Sorry the last 2 images are upside down)

 

Jim

 

 

 

 

Edited May 8, 2021 by JohnCh
Last 2 images rotated

[BlueBDA]

Makes sense Jim. I had to think about it for a while to understand why 2 plates, but I get it. Nice work. The screws that mount the belts look pretty tiny though?

[FE07]

You could make them larger but you'd have to drill through the mounting plate that comes with the harnesses.  If that size is good enough for Sabelt, it's good enough for me

 

Jim

[wemtd]

What grade & thickness steel plate did you use?

[wxywb021254]

Another option might be using simpson hybrid s instead. It is designed for even 3pt seat belt, so I would think it is fine with off center harness.

[Croc]

2 hours ago, wxywb021254 said:

Another option might be using simpson hybrid s instead. It is designed for even 3pt seat belt, so I would think it is fine with off center harness.

 

@wxywb021254 you are correct.  The Simpson Hybrid works correctly without needing modification.  I have one.  

[sf4018]

Do you have the 5th harness point going down into the seat between your legs?

[BlueBDA]

7 minutes ago, sf4018 said:

Do you have the 5th harness point going down into the seat between your legs?

5th and 6th - 6-pt harness.