Harness Bar vs. Half-Cage, and Airbags

[alexrobinson202]

I know this kind of thing has been discussed before, but it would be good to collect people's thoughts and get more people's views on it - normally whenever harnesses are discussed, most people just talk about the strap angle and that's about it.

So assuming you want the angle to be correct, and so are considering a weld-in harness bar or a rear half-cage, what are the safety differences between the two, for road driving? In theory the half-cage would give you a bit more protection, but in the real world, is this really necessary? I own a 172 Cup, which has coilovers and a few other bits but nothing crazy, but I am running fixed buckets (see pic below) so would like to get the harnesses sorted out properly. I would prefer to just go for a harness bar, as the cost will be much less, but would like to get people's idea on safety.

I should add that here I am discussing the safety relative to a standard car with normal seatbelts, rather than some high spec track car built to withstand anything!

An interesting point is the R26.R is available with or without the half-cage, so presumably Renault decided harnesses without a cage are safe enough? And interestingly, they seem to have ignored the rule about having harnesses straight completely! (see image below)

View attachment 75722

While we're at it, if you have got properly installed 4-point harnesses, are airbag's still of any use, i.e. what are the safety concerns about going to a non-airbag wheel?

It would be great to get people's thoughts on this, particularly if they have experience of a similar decision.
Cheers

 

[Silent_Scone]

Open for debate, but the thing to realise is that the stock belts will normally (or should) keep you head away from the roof of the car. If you've not got a cage in there at all, harnesses don't really let you go anywhere, so if the roof comes in you're going to know about it. In all honesty though in the event of a crash who knows where you're going to end up, but you shouldn't really run harnesses without a cage...really

 

[alexrobinson202]

Open for debate, but the thing to realise is that the stock belts will normally (or should) keep you head away from the roof of the car. If you've not got a cage in there at all, harnesses don't really let you go anywhere, so if the roof comes in you're going to know about it. In all honesty though in the event of a crash who knows where you're going to end up, but you shouldn't really run harnesses without a cage...really

Yeah I guess that's what I was considering, although is only a rear half-cage going to make any difference to this? And by the time you've rolled, wouldn't an inertia reel seatbelt lock anyway?

 

[dmallett]

Theres a lot of ifs and buts and variables with something like this tbh.

 

[MarkCup]

An interesting point is the R26.R is available with or without the half-cage, so presumably Renault decided harnesses without a cage are safe enough? And interestingly, they seem to have ignored the rule about having harnesses straight completely! (see image below)

View attachment 75722

I'd never thought of this...do Renault not have a clue as to what's safe, or is it general CS opinion that's flawed?

 

[.Adam.]

Yeah, what do Renault know about making cars?!

 

[alexrobinson202]

I'd never thought of this...do Renault not have a clue as to what's safe, or is it general CS opinion that's flawed?

Yeah I was surprised when I came across it to be honest, especially given how easily it would have been to use the cage! I can see how in theory straight harnesses will be better, but maybe Renault decided it wasn't such an issue.

Theres a lot of ifs and buts and variables with something like this tbh.

Yeah of course, I guess I was just after what the general opinion is, and what people actually are doing?

 

[dmallett]

In which case Mine are to the floor. Until I cage it.

 

[alexrobinson202]

In which case Mine are to the floor. Until I cage it.

I guess the problem that I can see is that having them to the floor puts a lot of stress in to the actual seat during a crash, which maybe Renault planned for, but normal buckets dont?

 

[tommyl]

The most quoted reply to running harnesses and fixed back seats without a cage is the risk of serious spinal injury. In a road car I believe the inertia reel and reclining seats allow the user to move around in the event of an accident. With a fixed bucket and harness you can't move at all, hence collapsing roof collapses your spine.

From a personal experience many years ago, where my brother and I rolled my car a number of times slowing down from 65 mph, I know that my brother walked out of the car whereas I had to be dragged out due to injury. I wasn't wearing a seatbelt. He was, and not only that, the roof on his side of the car had been flattened to the line of the bottom of the windscreen! I would not like to know the result if he was using a fixed bucket and a harness.

Personally I've only used harnesses with a full cage in a previous track only car; and a Schroth quick-fit harness with OEM seat in a previous road car (only when on track). If push came to shove, I would use harnesses and fixed buckets without a cage 'now and again'. It's down to how much risk you want to take.

 

[alexrobinson202]

The most quoted reply to running harnesses and fixed back seats without a cage is the risk of serious spinal injury. In a road car I believe the inertia reel and reclining seats allow the user to move around in the event of an accident. With a fixed bucket and harness you can't move at all, hence collapsing roof collapses your spine.

From a personal experience many years ago, where my brother and I rolled my car a number of times slowing down from 65 mph, I know that my brother walked out of the car whereas I had to be dragged out due to injury. I wasn't wearing a seatbelt. He was, and not only that, the roof on his side of the car had been flattened to the line of the bottom of the windscreen! I would not like to know the result if he was using a fixed bucket and a harness.

Personally I've only used harnesses with a full cage in a previous track only car; and a Schroth quick-fit harness with OEM seat in a previous road car (only when on track). If push came to shove, I would use harnesses and fixed buckets without a cage 'now and again'. It's down to how much risk you want to take.

Cheers for your advice, sounds like you were lucky to make your way out of that one!

I of course don't want to discredit your view, but just found this on the net which is an interesting read on this topic:

http://www.justracing.com/driver_safety/viewtopic.php?p=90

Basically says that almost all injuries in a roll-over accident are due to your head hitting the b-pillars or similar, and so that a harness, even without cage, is the safer option.

Of course, as mentioned in the story above, there will always be exceptions to this!

 

[JackJack]

Surely Renault wouldn't be allowed to sell the R26r like that if it was unsafe?

Edit: Interesting info in that justracing link.

 

[alexrobinson202]

Surely Renault wouldn't be allowed to sell the R26r like that if it was unsafe?

Edit: Interesting info in that justracing link.

Yeah you wouldn't have thought so!

The more I read on this it seems you just cannot win, because if you run a roll cage but have no helmet then there's risks there too!

 

[Sam@NP]

Harnesses have to be mounted at the correct angle to meet MSA/FIA regulations.

The only downside in terms of safety regarding harnesses is that in a big enough head on collision the occupant could suffer from a greater whiplash compared to a standard 3 point seat belt. This is why Hans Devices where introduced. In all other crashes id much rather be in a harnesses, all this 'if you roll you can move out the way of the roof' is utter b****cks the G force on your body means you have no control over your movements. FACT Id rather stay as still as possible in a crash.

Harnesses really do have draw backs such as not being able to reach things like heater and radio controls but I much prefer them.

The more I read on this it seems you just cannot win, because if you run a roll cage but have no helmet then there's risks there too!

There is only a risk is if you can hit your had on the cage, but then what design a cage/seat position if you can hit your head on it.

 

[alexrobinson202]

Harnesses have to be mounted at the correct angle to meet MSA/FIA regulations.

The only downside in terms of safety regarding harnesses is that in a big enough head on collision the occupant could suffer from a greater whiplash compared to a standard 3 point seat belt. This is why Hans Devices where introduced. In all other crashes id much rather be in a harnesses, all this 'if you roll you can move out the way of the roof' is utter b****cks the G force on your body means you have no control over your movements. FACT Id rather stay as still as possible in a crash.

Harnesses really do have draw backs such as not being able to reach things like heater and radio controls but I much prefer them.

Absolutely, the confidence and (in my opinion at least) ability to react quicker to things because you feel them through the whole car is brilliant. Even just for slow driving, there have been a few occasions where I've caught the tail from stepping out in serious rain or similar, which I don't think I could have done in time before. And I sit relatively close so the heaters are no problem!

And I agree, either way I'm going to get them set at the right angle, for piece of mind as much as anything else

 

[Sam@NP]

Ideally they should be mounted at the correct angle and if my car wasnt a road car it would have a rear cage simply so I can have mine at the correct angle.

 

[alexrobinson202]

And what are people's thoughts on the airbag question? Are they of any benefit if using harnesses?

 

[Sam@NP]

I guess they wont be a bad thing, have you ever experienced an airbag? Loud bang, burnt arms and very hard, not the soft marshmallow most people expect them to be.If its an out and out track car with correct harnesses and seat Id bin mine but not if its a road car and you are keeping the 3 point belts as well.

 

[MarkCup]

Very, very interesting.

So it does seem as though all the CS experts who said my Cup was dangerous and that I was a f***ing idiot...were in fact...wrong (or at least not 100% right)!

LOL

As for airbags...I can't see how they'd materially benefit you with a full harness.

 

[alexrobinson202]

I guess they wont be a bad thing, have you ever experienced an airbag? Loud bang, burnt arms and very hard, not the soft marshmallow most people expect them to be.If its an out and out track car with correct harnesses and seat Id bin mine but not if its a road car and you are keeping the 3 point belts as well.

Thankfully not, though I can imagine it's not exactly pleasant, even if the crash itself isn't too bad!

I'll be using harness all the time but it's still a road car, so maybe a 197 wheel is the way to go.

 

[alexrobinson202]

Very, very interesting.

So it does seem as though all the CS experts who said my Cup was dangerous and that I was a f***ing idiot...were in fact...wrong (or at least not 100% right)!

LOL

As for airbags...I can't see how they'd materially benefit you with a full harness.

I feel like I may have opened up a big can of worms here, I think we can all agree that having harnesses at the right angle can't be a bad thing (I assume this is what you're discussing), but is maybe not necessary. But further than this is where the debate starts!

And with airbags, does anyone know how far back in to the car they go? E.g. if one was to go off with you just sat normally in your seat, would it reach you?

 

[Heez]

I feel like I may have opened up a big can of worms here, I think we can all agree that having harnesses at the right angle can't be a bad thing (I assume this is what you're discussing), but is maybe not necessary. But further than this is where the debate starts!

And with airbags, does anyone know how far back in to the car they go? E.g. if one was to go off with you just sat normally in your seat, would it reach you?

If you have no HANS or the likes it could do more damage than good. Front impact, head goes forward, airbag deploys, face to airbag, head smash the headrest in bucket, bucket is rigid, knocked unconscious.

Might I add I have no idea if this would happen as I have no idea if the bag would get that far. It's just what I would think would happen.

 

[Sam@NP]

^ that wouldnt happen my dear.

 

[Heez]

^ that wouldnt happen my dear.

Eased my mind if I ever get buckets + harnesses without changing to an aftermarket wheel. Fanx.

 

[alexrobinson202]

While we're on this topic, has anyone actually got a weld-in harness bar fitted, or know somewhere in Hampshire that could do this kind of thing?

 

[MarkCup]

I think we can all agree that having harnesses at the right angle can't be a bad thing (I assume this is what you're discussing), but is maybe not necessary. But further than this is where the debate starts!

I was talking more about the;

"Having harnesses and fixed buckets but without a fixed cage is a retarded thing to do"

comments that usually surface.

Learned a lot from this already...good topic!

 

[warwickstingray]

I ran an XR2 with a full cage, buckets and harnesses. It was a track only car so We ran in modified so had an msa guy round to check the car and gives us a log book. He was completely satisfied the car was safe.

Every single f**king event we did we were told buy a different scrutineer that we should have our harnesses mounted this way and then that way and that was just the tip of the iceberg. they would always find something they didn't like. We did initially move stuff as were told as we assumed they knew best but after a whole season of not one scrutineer saying the same thing as another we went back to what got the log book in the first place and just nodded in agreement when someone commented. Best one was our FIRST event with the car and we were given a bollocking because we'd been told before about where some roll cage padding was fitted.

No matter what you do someone will tell you it's unsafe. What got on my nerves was that i never actually got to the bottom of what was best. Unless someone did crash testing of our particular car there was no way of knowing.

If it was me i would use the MSA rules as a guide. If it's good enough to compete then it's good enough. As far as i know you can download the bluebook online.

 

[Struggler]

I have a bolt in harness bar!!

im glad Sam said exactly what i was thinking. An inertia reel seatbelt is designed to hold you in place, not to "give you some room to move around" crashes happen in split seconds, nobody will sit there thinking

"Hmm im experiencing a car crash, and the roof is caving towards me faster than i feel comfortable with. Im just going to move myself slightly to get out of its way".

and even if somebody could think that fast, during the crash you're going to be experiencing some epic G-force in almost every direction, that and the adrenaline pumping, i doubt youll even be able to move!!

Secondly, if i was to have a cage supporting my harnesses, id want the kind of cage that mounts to the seatbelt anchors rather than ones drilled through the arches. This is because in a crash, the former cage will be trying to sheer bolts mounted in a double skin, whereas the latter will be trying to tear the skin to pull the mounting bolts though (which is much easier)

Finally, i have harnesses and not airbags. Airbags are designed to stop you hitting the steering wheel. Correctly worn harnesses means you wont hit the steering wheel anyway so whats the point?! theyre heavy too .

These are my harnesses, im not sure on the exact angle of them but its slightly better than the floor option. also its secured by 6 10mm high tensile steel bolts perpendicular to the direction of force.

remember the rules people are preaching are for FIA regulation. theyre drawn up as safety regulations for RACING purposes, and to say that theyre strict, is a bit of an understatement.

 

[Sam@NP]

A scrutineer ask us to prove our roll bars where steel and not ally, so we placed a magnet in it at which point he replied that proves nothing. :banghead:

 

[Heez]

A scrutineer ask us to prove our roll bars where steel and not ally, so we placed a magnet in it at which point he replied that proves nothing. :banghead:

That's bad. Like really bad. How can somebody not know something like that yet tell you if somethings safe or not?

 

[alexrobinson202]

I have a bolt in harness bar!!

im glad Sam said exactly what i was thinking. An inertia reel seatbelt is designed to hold you in place, not to "give you some room to move around" crashes happen in split seconds, nobody will sit there thinking

"Hmm im experiencing a car crash, and the roof is caving towards me faster than i feel comfortable with. Im just going to move myself slightly to get out of its way".

and even if somebody could think that fast, during the crash you're going to be experiencing some epic G-force in almost every direction, that and the adrenaline pumping, i doubt youll even be able to move!!

Secondly, if i was to have a cage supporting my harnesses, id want the kind of cage that mounts to the seatbelt anchors rather than ones drilled through the arches. This is because in a crash, the former cage will be trying to sheer bolts mounted in a double skin, whereas the latter will be trying to tear the skin to pull the mounting bolts though (which is much easier)

Finally, i have harnesses and not airbags. Airbags are designed to stop you hitting the steering wheel. Correctly worn harnesses means you wont hit the steering wheel anyway so whats the point?! theyre heavy too .

These are my harnesses, im not sure on the exact angle of them but its slightly better than the floor option. also its secured by 6 10mm high tensile steel bolts perpendicular to the direction of force.

remember the rules people are preaching are for FIA regulation. theyre drawn up as safety regulations for RACING purposes, and to say that theyre strict, is a bit of an understatement.

That looks good, where did you get the bar from? I agree, pretty sure there's no way at all you'd be able to move out of the way (deliberately anyway) of a collapsing roof! Just comes down to luck by that stage really.

Interesting what you say about airbags - is their main purpose to stop you hitting the steering wheel as you say, or to also slow you down more slowly?

 

[Sam@NP]

Using a standard rear brace is not sufficient as a harnesses mounting bar however a weld in one would be if constructed properly Ill get a pictures of a mates to show this.

 

[Struggler]

Sam, is that comment about the standard rear brace aimed at me?! the mounting places are 3mm steel and theres a plate on both sides of the shell. do you not think this is sufficient??

That looks good, where did you get the bar from? I agree, pretty sure there's no way at all you'd be able to move out of the way (deliberately anyway) of a collapsing roof! Just comes down to luck by that stage really.

Interesting what you say about airbags - is their main purpose to stop you hitting the steering wheel as you say, or to also slow you down more slowly?

how do you figure the "more slowly" technically they slow you down faster as theyre deploying in the opersite direction and as sam said, theyre very hard and rough.

And sorry i dont know where its from, it was donated to me from my friends track car!

 

[Sam@NP]

Sam, is that comment about the standard rear brace aimed at me?! the mounting places are 3mm steel and theres a plate on both sides of the shell. do you not think this is sufficient??

Not at all, its aimed at the many cars we see that are mounted on a standard rear brace. I like your mounting.

 

[mark123]

An interesting point is the R26.R is available with or without the half-cage, so presumably Renault decided harnesses without a cage are safe enough? And interestingly, they seem to have ignored the rule about having harnesses straight completely! (see image below)

View attachment 75722

MSA rules are +/- 10 degrees from horizontal preferred but up to 45 degrees down is OK.

Difficult to tell from the pick but it looks less then 45 degrees to me, so would be OK.

I think in a mk2 clio the rear seat belt mounts are closer to the front seats so the angle is over 45 degrees.

 

[alexrobinson202]

how do you figure the "more slowly" technically they slow you down faster as theyre deploying in the opersite direction and as sam said, theyre very hard and rough.

And sorry i dont know where its from, it was donated to me from my friends track car!

I mean that surely they deform as you hit them, that being the point of them, so they slow you down faster than just reaching the limit of your seatbelt and stopping? Although it's obviously not quite this simple as seatbelts strain under heavy loads, but I thought that was the idea of an airbag.

And no worries, does anyone know where I could get a weld-in one from?

 

[alexrobinson202]

MSA rules are +/- 10 degrees from horizontal preferred but up to 45 degrees down is OK.

Difficult to tell from the pick but it looks less then 45 degrees to me, so would be OK.

I think in a mk2 clio the rear seat belt mounts are closer to the front seats so the angle is over 45 degrees.

Ah ok, that's interesting - the angle does look a lot less in the Megane than the Clio. So they advise ±10 degrees, but up to -45 is acceptable?

 

[Silent_Scone]

It is actually fact that standard seat belts are designed to throw you forward in the event of a roll, btw. Standard in car safety, defying gravity since the 1900s

 

[172Ben]

http://www.schrothracing.com/sdocs/2009_Competition_Instructions.pdf

TBH, id rather follow the guide, than find out what happens if i dont and id defo have an anti-sub strap as well if i went harnesses again

 

[Struggler]

cant fault you there Ben, i think im going to look into some of that spreader material!!