Schroth Harness & FHR

[Dobson_justin]

A bit of advice please regarding my car’s harness.  I have a Schroth 4point harness at the moment, which has 2” belts at the shoulder, expanding to 3” further down towards the buckle. So has previously been used with HANS presumably, as it was a race car.  I have no idea what model harness it is.

I cannot work out what is correct and what is not from the various Schroth safety guides available online which are may as well be in another language, so thought I would ask for help. My questions below, any help gratefully received!

I have no idea if my harness has the Schroth ASM technology included to stop anti-submarining, or what this even should look like - can anyone help me identify this?

Can I use the 2” belts without Hans in Sprint events?

If I have to buy a HANS device, what do I go for? I think the harness chassis mounting points may have been moved closer together, as there is at least one extra hole in the boot cover. My shoulders are level with the mounting points, so belts are level from mounts to my shoulders. Can I just buy a Hans that fits my neck? Or is there something I am missing?

Does the Simpson Hybrid allow the use of 2” belts?

Should I change to a 6 point harness?  Or just buy the anti sub strap? Have no idea which one fits a Caterham, but assume this fits to the 2 mounting points at the back of the floor.

As you can see, I really have no experience in this, so any advice welcome?

Thanks! 

[Dannyboy]

You really do need the crotch straps fitted to prevent submarine gold.. Unsure whether you can use 3”, however several manufacturers do sell 3” HANS compliant straps. I know mine are HANS compliant from Simon at Meteor and are 3” shoulder straps. 

Holes- there is guidance online for spacing with Hans and angle behind the seat. I can’t recall recommended spacing but some guidance here https://www.tillett.co.uk/shop/documents/downloads/seat-belt-fitting-information-2012.pdf

And, I do have a very sexy Stand 21 Ultimate carbon Hans available size L, 20 degree, only as personally i really didn’t get on with it..

[Shaun_E]

We have 2" belts with Simpson Hybrid FHR and that works really well. If I didn't have an FHR I'd prefer to have 3" belts.

If the belts are level as they go over your shoulders then that's OK - between 20 deg and 0 deg is recommended. If they sloped down that's no good.

I would definitely recommend 6 point harness.

[Richard Price]

Justin,

I'd really recommend changing to a 6 point harness (preferably the style where there are individual crotch straps that pass through a loop on each lap strap).

Unlike Dan, I'm happy using a conventional 20° HANS. I'm only aware I've got it on when I'm in the paddock (but, can easily unclip the teathers from my helmet to allow my head to turn enough to be able to reverse into a paddock spot).

My shoulder straps are actually fixed to the underside of the rear bulkhead crossmember, and pass through the bulkhead panel, so that the harness's are a suitable angle in the horizontal plane.

[Dobson_justin]

Danny boy, Shaun and Richard thank you for your advice, really helpful as always. Dave Gemzoe came to my house today with his HANS to check, and all looks ok, and I understand a bit more now. As usual, it is not that complicated but trying to figure it out on your own is quite tricky.

Just need to get my crotch straps now and I will be sorted.  

Thanks again 

[Simon.Rogers]

I would very much advise 2" with any FHR.  Personally I could not get the 3" belts tight with the FHR.

If you can imagine although the 3" belts are approved for use with all FHR's the belt tends to curl up.  Then as you tighten you are only placing a strain on the top of the curled edge.  The belt itself remains a little loose.

As soon as I swapped to 2" it all felt natural and I was able to feel tight in the car again.

Each to their own but I like the Simpson Hybrid and it always looks easier to get into the car without the device and helmet already fitted.

[Richard Price]

"it always looks easier to get into the car without the device and helmet already fitted."

 

I don't have a problem.

I climb into the car, slip the HANS over my shoulders, fasten the harnesses, put my helmet on, then clip the tether clips onto my helmet. I find the clips easy to fit and remove by feel. 

[SimonR300]

Hello d-j,

I might be too late but here's my advice anyway.....

I too have an ex-racer and use my car for sprints, hillclimbs and trackdays and have replaced all the seats and belts in the last year.

If the car was raced with the belt sizes you have, it more than likely had crutch straps.  Are you sure they are not still there?  What seat do you have?

2nd thing to check is the expiry date of the belts.

If you are not sure that the current belts have never suffered  "an abrupt halt", replace them.

The Schroth asm will be the yellow bit on one of the shoulder straps.  As far as I can see, none of the racing 4 point harnesses have 

 

2" shoulder and 3" lap belts.  Which also suggests it was a 6 point harness originally.

2" shoulder straps will cut in to your shoulders too much without a Hans, best use 3" shoulders.  The Sprint event regulations should tell you if you they are run under MSA/Motorsport Uk regs which will also determine if you need to use a Hans.  A helmet with Hans posts too, obvs.

The Hans does require the shoulder straps to be closer, another reason I think you had a full race 6 point Hans harness.

The adjustable Hans has been discontinued, so yes you need the neck size and the angle.  As already said, 20deg should be the one.  If you use the Hybrid FHR then angle isn't an issue and you should use 2" shoulder belts with it.

You are right to consider the shoulder to mounting point angle.  There is plenty of info and regulation on that point.  You should be ok as you are I think.

Best thing is to read all the regs etc and buy a new harness.  Schroth do a Caterham specific 6 point (with or without Hans 2' or 3")

eg:    https://caterhamparts.co.uk/seatbelts-harnesses/6490-schroth-6pt-rh-kit.html

Hope that fills in some of the blanks!

[Dobson_justin]

Thanks Simon. Much appreciated. All sorted now, crotch straps now obtained and installed, and Hans purchased, so I am ready to go I think.