Cheap helmets for autocross, Does this sound wrong to anybody else? Options

[sgarnett]

I personally would like to see more dual-certified helmets.

The impact testing between SA and M helmets is mostly identical (same number of impacts, same energy, same flat, edge, and hemispherical anvils). The SA test does add a cylindrical rollbar anvil test, but this is not cumulative. In other words, it does not add any additional impacts to one site, it just uses a different type of anvil for an additional test on a different site.

The value of the SA flame-retardant requirement should be self evident.

I suppose the wider periphral vision requirements for M helmets might not be applicable to some forms of auto racing, but in general I think unobstructed vision reduces the likelyhood of an accident and is therefore safer.

I want a helmet that meets BOTH standards (and still fits).

[robz71lm7]

I cringe everytime I see a harness that's mounted below the shoulders. It's a spinal fracture begging to happen. No doubt the owner feels much safer, though.

That was something I had thought of, but forgot to bring up. I see tons of intelligent people at local autocrosses that have their shoulder harness mounted to the floor. I chuckle and think of Darwin. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/tongue.gif) Maybe that is how I should look at all of this.

[00 Trans Ram]

Well, I must admit that I've got a 5-pt harness, and no roll cage.

I will qualify that, however. One, it is attached to the "baby seat" holders on the rear deck. Those things are rated to hold about 60lbs, so I daresay that they'll rip out in the event of a bad crash. Plus, they're about 2 inches below my shoulders,and 5 feet back. I really don't think that I'm in danger of spine compression. I also wear my seat belt below my harness, just in case.

I really don't get the guys who bolt it to the rear seat bolts. They're both permanent and below the shoulders!

[trackbird]

I'm sure they will hold more than 60 lbs. If that were true, I should be able to hook a strap to it and yank it out of the car (not happening). While I agree, you'll not be likely to see a spinal injury, you may see enough belt stretch to hit the steering wheel (if it ever came to that kind of impact). Not perfect, but only you can make that call.

[sgarnett]

I see tons of intelligent people at local autocrosses that have their shoulder harness mounted to the floor. I chuckle and think of Darwin.

Remember that not everyone (intelligent or not) has your level of familiarity with vector addition. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/wink.gif)

My point was that sometimes it isn't obvious whether an action actually furthers your goals or not.

BTW, I can't bring myself to try a torso strap for autocross either. It just seems like it would be very dangerous in an accident. If it's placed high enough (mid sternum) it might be OK, but I'd still be worried about spinal damage.

[LT4Firehawk]

The SA helmets are tested against a rollbar anvil and are struck 3 times in each test zone.

While you are correct on the addition of the 4th test (roll bar), which is tested 3 times, the other tests are all exactly the same as the M standard and are either 1 or 2 impacts:
2 on flat anvil
2 on hemisperical anvil
1 on edge anvil

I really don't get the guys who bolt it to the rear seat bolts. They're both permanent and below the shoulders!

The rear seatbelt mounting point is far enough back that the angle created is acceptable to meet DOT restraint standards IF they are used with an appropriate restraint system like those from Schroth, which has a unique anti-sub-marining design ( http://www.schroth.com/products_en/asm.htm ). Unfortunately, I think many people have seen these belts in use like this in other cars and think they can use any harness safely like this, which is not the case.

[00 Trans Ram]

Come to think of it, you're probably right (about the "holding 60 lbs" part). I asked one of the guys at the dealership, and he did some "research" and that was what he came back with. Of course, that may have just been how much change he had in his pocket, or the air temp that day. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/laugh.gif)

I'm not overly worried about belt stretch, as I also wear my regular seat belt.

Thanks for the concern! I'm always open to suggestions!! (IMG:http://www.frrax.com/rrforum/style_emoticons/default/smile.gif)

[sgarnett]

Well, I must admit that I've got a 5-pt harness, and no roll cage.

I will qualify that, however. One, it is attached to the "baby seat" holders on the rear deck. Those things are rated to hold about 60lbs, so I daresay that they'll rip out in the event of a bad crash. Plus, they're about 2 inches below my shoulders,and 5 feet back. I really don't think that I'm in danger of spine compression. I also wear my seat belt below my harness, just in case.

The role of the harness is to keep you firmly upright and in your seat (including your head). The role of the rollcage is to prevent the roof from meeting your head. Using the harness without the cage means your body can't move when the roof reaches your head (IMG:http://www.frrax.com/rrforum/style_emoticons/default/wink.gif)

Ignoring that, though, you'd be better off with the belts anchored 2" ABOVE your shoulders. Even anchoring them at the same level causes compression as your body is thrown forward and increases the tension.

You might be better off making some kind of adaptor (from steel) that mounts temporarily to the childseat anchors, but raises the belt anchors. Another approach is the harness bar, but I'm not sure it's high enough either.

[Dewey316]

you'd be better off with the belts anchored 2" ABOVE your shoulders. Even anchoring them at the same level causes compression as your body is thrown forward and increases the tension.

Interesting enough, simpson recomends the should straps be mounted below shoulder level.

(IMG:http://www.teamsimpson.com/catalog/restraints/restinfo/big_up6pt.gif)

I had always heard that it had to do the angle of shoulder strap, compared to the shoulders.

[00 Trans Ram]

Well, I actually thought of another problem with my setup. I was betting that the anchors would give way in a serious crash, allowing me to move around freely when/if the roof gives way. However, if my regular seat belt holds me in, then I won't be thrown forward enough to break them. Which means that I'll be sitting straight up in a rollover.

Now, this risk MAY be worth it at my home races. The runway is bordered by trees. You go from concrete to wood wall. Not much chance of a rollover (you'd hit trees first). But, I'm going to really think about this for places with wide open runoffs into sand or dirt.

Question about the 2" above part. Is that "absolute 2" above your shoulders" or "relative 2" above your shoulders"? Meaning, if I were to sit straight up, they should be 2" above. But, I sit semi-reclined (not lowrider - more like 20-30 degrees from straight up). If you look at the angle formed by the belt as it comes over the seat, it forms about a 60-70 degree angle. So, in relation to my shoulders, the harness is actually above them. But, measured from the ground, it is below or even. Which is the preferred method?

[robz71lm7]

The SA helmets are tested against a rollbar anvil and are struck 3 times in each test zone.

While you are correct on the addition of the 4th test (roll bar), which is tested 3 times, the other tests are all exactly the same as the M standard and are either 1 or 2 impacts:
2 on flat anvil
2 on hemisperical anvil
1 on edge anvil

I really don't get the guys who bolt it to the rear seat bolts. They're both permanent and below the shoulders!

The rear seatbelt mounting point is far enough back that the angle created is acceptable to meet DOT restraint standards IF they are used with an appropriate restraint system like those from Schroth, which has a unique anti-sub-marining design ( http://www.schroth.com/products_en/asm.htm ). Unfortunately, I think many people have seen these belts in use like this in other cars and think they can use any harness safely like this, which is not the case.

Yes, as I said in my other post the 4th test is the difference-I didn't mean to imply the other impact tests were any different. I see I wasn't entirely clear there.

On to the belts...

My issue isn't with submarining (although I see how that could happen), but rather with spinal compression. It's funny you mention Schroth, because those are the belts some guys are using locally. I've seen them making a roughly 45* angle with the seat/floor. Ideal is around 5 to 10*.

Man I didn't expect this to turn into a long thread. And btw, I'm no safety nazi. In fact I find the safety program here at work (power plant) to be quite annoying at times.

[John_D.]

You're on a good point there. The harness mounting point makes some difference.

But it seems to me, that my seat, with harness cutouts, defines the harness angle, relative to my shoulders....

And those cutouts are low. So any tension in the belt creates a downward force on my shoulders, no matter where the harness is anchored.

[trackbird]

I think Simpson lists the 10 degree downward angle as a way to keep you from impacting the roof due to belt stretch. You begin to deal with the "lesser of two evils". Do you risk spinal damage or a head injury, etc? That may be the question and yet somehow, the solution?

[sgarnett]

Question about the 2" above part. Is that "absolute 2" above your shoulders" or "relative 2" above your shoulders"? Meaning, if I were to sit straight up, they should be 2" above. But, I sit semi-reclined (not lowrider - more like 20-30 degrees from straight up). If you look at the angle formed by the belt as it comes over the seat, it forms about a 60-70 degree angle. So, in relation to my shoulders, the harness is actually above them. But, measured from the ground, it is below or even. Which is the preferred method?

First of all, I said 2" above because you said 2" below. I was just trying to make the point that "almost horizontal" is not good enough. I'm was not trying to imply that 2" is the magic number - I don't want to lead anyone astray.

That Simpson picture shows the belt anchored below the shoulders (apparently to keep your head off the roof), but assuming it's reasonably to scale, the angle from pelvis to shoulders to belt anchor is still significantly greater than 90* to reduce the risk of compression fractures.

Ignoring the issue of keeping you in your seat, it's the relative angle of the belt compared to the spine that matters for protecting your spine.

[sgarnett]

Man I didn't expect this to turn into a long thread. And btw, I'm no safety nazi. In fact I find the safety program here at work (power plant) to be quite annoying at times.

What the heck, it's a good topic to discuss every now and then.

[Dewey316]

Ignoring the issue of keeping you in your seat, it's the relative angle of the belt compared to the spine that matters for protecting your spine.

that is the way I had always understood it should be at a 90* angle compared to the spine, but being that most of us do not sit with our spines vertical, the mounting does end up being below shoulder level.

[trackbird]

Safety Nazi has always been my job. Just ask Mitch (IMG:http://www.frrax.com/rrforum/style_emoticons/default/wink.gif)

[Jeff97FST/A]

I've seen installation diagrams before (in addition to the Simpson pic) that show the shoulder belt mount 90* to the line formed by the shoulder belt as worn by the driver. The 90* mount causes the load on the belt to be in a straight line during an accident, not pulling down on the spine as it would at greater than 90, or allowing the body to rotate forward, as it would at less than 90.

My understanding of the submarine strap is to prevent the lap belt from riding up on the drivers torso. During an accident, the body pivots forward, the shoulders want to rotate away from the seat. As the body rotates, the rear mounting point for the shoulder harness stays stationary (we hope), effectively lengthening the distance from rear mount to the shoulder, shortening the distance from shoulder to lap. The shortened distance from shoulder to lap wants to pull the lap belt up on the torso, allowing the body to slip under the lap belt.

A properly installed sub strap (I think parallel to the line of the shoulder belts) keeps the lab belt placed across the hips.

[00 Trans Ram]

Well, Sean, I think I'm safe. But, I am gong to take it to a shop that installs these things for local drag cars. They will be able to look and see. Thanks for bringing it up! I'd MUCH rather question what I am doing than just drive around ignorant!!

[jraskell]

Here's pics of my helmet after a 40mph highside. Happened a little over 4 years ago.

(IMG:http://home.comcast.net/~jraskell/helmet_damage_2.JPG)

(IMG:http://home.comcast.net/~jraskell/helmet_damage_1.JPG)

I can't find pics of my leather jacket after the event. It was in pretty rough shape as well. I walked away, though with a noticable limp from re-establishing contact with the pavement right hip first.