fatbillybob

I use the dual shoulder schroth belts and hans w/o QR tethers. I do this out of personal paranoia. I use a full containment seat too and it is all really tight. It is much harder to get in the car and attach all the shoulders. The 3" belt has to go on the shoulder and you need to wiggle the 2" over the hans yolk with a helmet on your head. It is harder than you think. Then you need to make sure all 4 straps are not twisted or partially hung on the hans to make sure when you tighten the belts you have not kinked them. We had a discussion a while back where you metioned and I agreed with you on the schroth issue of lap belt anchor length and getting the adjuster too close maybe stuck on the seat lap hole. The same kink is possible with twice as many shoulder straps. While doing all this I have visions of disconnecting my hans qr tethers as they get stuck or I pull them as I am figgeting with the shoulders. So I don't use the qr's but I always have a knife handy. I have had to exit a fire with hans and the 4 belts and I got out fine.

fatbillybob

oh so why do I use the dual shoulders? 1) percieved increase in system effectiveness 2) they are more comfortable with hans than a 3" shoulder system without a hans.

Are they worth the trouble? I ask myself that question every time I strap into the car.

fatbillybob

I was at a lecture by Dr.Hubbard. He thought the 323 belts was to sell more belts. He saw no material value. He did like the dual shoulder strap system.

chris walrod

OK, now that I am back from other places, I have finally uploaded an image of an example with respect to the double, over the shoulder bolder holder

Here is one way to mount it:

Circuit Motorsports

Thanks. Looks nice. I was wondering what the mount looked like for a open wheel/sports racer. Or is that one of the Pimpy carbon fiber NASCAR seats that Hendrick makes.

However teh spread looks far greater than you want for a HANS device. IIRC the spread between the 2 inner edges of the belts is supposed to be 3 inches.

FlyingDog

That is one jerry rigged high tech seat.

Bryan Watts

The spread is determined by how far behind your shoulders the belts mount. In the case of a single seater or a seat like above, the belts mount right at your shoulders...mounting them 3 inches apart would cause the belts to wrap around your neck. In some instances where the belts mount a long ways behind the driver, HANS actually suggests crossing the belts according to the literature that came with my HANS from HMS.

Bryan Watts

Just looks like they've done a foam insert to fit the driver and then covered it in tape for durability. It's a pretty standard setup in single seaters I've driven.

Circuit Motorsports

Nope not according to HANS. Those belts are probably about 6-8 inches behind where the driver neck would be.

Circuit Motorsports

Here is an article aobut one of those high tech seats getting the bead seat poured.

http://sports.espn.go.com/rpm/column...vid&id=3161760

You can either cover them with gaffers tape or a bit of fabric, usually nomex.

As Bryan said it's pretty standard to see seats like that in open wheel.

Bryan Watts

Perhaps my eyes are tricking me, but those belt mounts don't look to be nearly 6-8 inches from the driver's neck. They appear to mount to the carbon bulkhead that the driver's back is against.

There are VERY FEW tin top cars where the belts can be mounted within 8 inches of the driver's neck. A traditional seat and harness bar setup almost always has more room than that.

Further, the suggestion to mount the belts close together is to help keep the belts on the HANS. The double strap setup would seem to help solve that problem while allowing for a more traditional mounting setup. Perhaps the direction for the double mount are different?

SundayDriver

Chris - thanks for posting - very educational.

I too, have seen instructions for crossing the belts for a HANS depending on how far they are from the driver.

Circuit Motorsports

Standing with my back against a wall my neck wearing a tshirt my neck is 3.75 inches from the wall another 1.5 inches for seat foam and drivers gear and you are right at 6 inches. I've been fabricating a mount in my FC and was shocked how far my neck was from the belt mounts. Yep. That's one hurdle that the doorslammers have to contend with vs. the purpose built cars.

Didn't think fo the double belts needing a different geometry. That could explain it.

As for the belt crossing I know that a number of Skip Barber people have done it since their harness mounts are pretty wide.

gbaker

From a NASCAR Cup car:

chris walrod

This seat is very typical of the open wheel crowd, crude as it looks. Gaffers tape is the interior material of choice simply because drivers are often times having their seat adjusted here and there for max comfort.

Drivers are really really sensitive how the seat fits particularly around their Sciatica nerve near their butt. If a seat doesnt fit properly in this particular area, a drivers legs stand a chance of going to sleep, or numbing. No bueno.

So, this is one reason why gaffers tape is the tuck-n-roll of open wheelers