Roll Over Protection discussion

[bigdog]

To avoid hijacking another thread I will make this a new topic. There has been some discussion regarding the 'functionality' of roll bars available for the MX-5 NA and NB models - do they offer any protection in a roll over situation. My contention based on previous experience is that any bar is better than none, and that bars like the Brown Davis and MX-5 Plus models offer a great degree of protection to the occupant. Here is your chance to voice your opinions and experiences. Remember that it is up to each individual to make their own choice on the matter - I just thought it would be useful to draw peoples' comments together for reference. Go to it...

[deviant]

Yes they do: http://www.bethania-garage.com/testimonials.htm

Also see here:

http://www.youtube.com/watch?v=qMmjaaSQP08

The after photos..

http://www.flickr.com/photos/benellett/4323393345/

http://www.flickr.com/photos/benellett/4323393531/

http://www.flickr.com/photos/benellett/4324128254/

http://www.flickr.com/photos/benellett/4324128498/

http://www.flickr.com/photos/benellett/4323392891/

The manufacturers you mention make products almost identical to the Hard Dog kit. The video and various photos prove that a major accident IS survivable with this style of roll over protection but I also think some (a lot) of this is down to the luck of your head and arms staying within the car and not rolling over anything that would intrude in to that space.

Something to keep in mind with these roll over bars is that they ONLY offer some roll over protection and do nothing for side or front impacts. Lots of people that have them (myself included) protrude slightly above the bar with a helmet on which is not ideal at all especially if you use a seat and harness (like me).

I would strongly recommend that anyone using one of these bars in a road car make sure the thing is well padded with proper cage padding. As an average height guy of a *ahem* 'husky build' my seating position and height meant that in an accident the back of my head would smack the bar. I had to keep the passenger seat position slightly forward, with it slid right back the passenger is practically sitting under the bar and could hit their head on it. Having said all this have you ever seen the haggard metal crap an inch from your head with the roof up?!?! With a Sparco V on stock rails I do not sit that much lower than stock but the seat headrest is high enough that I would not contact the cage in a crash, it is still padded though.

One more point to make about roll over protection. Avoid at all costs this kind of JDM hekit y0 crap, it will do nothing for you in a big one and is more likely to pose a danger than anything else:

[Old Dude]

I have been in a roll over and it wasn't on the track or anything remotely close..... it was on a suburban rd and we were T boned.

After that experience, the first thing I put on my MX 5 was an MX5 plus twin hoop roll bar. Apart from the chassis rigidity increase the peace of mind in knowing that I have some protection, in the event of a roll over is a huge bonus.
I would not have a convertible with out one.

Cheers
Dale

[snshami]

I agree a good roll bar is better than nothing unless it is positioned wrongly and you hit your head on it in a non roll over accident.

Having said that a vast majority of tintop cars on the road today that are more than 10 years old do not have sufficient roof crush strength. Drivers of those cars might think they are protected in a rollover but are not really.

I think for the road the answer is to drive carefully and not get in a situation you cannot control. The most important and sophisticated safety feature in any car is between the driver's ears.

For the track I agree rollover protection should be mandatory.

[timk]

I wouldn't be without one, and I know the amount of engineering effort that has gone into the MX-5 Plus bar.

[deviant]

One thing I wonder about with the type of ROP's we all use is if the mounting to the seatbelt mounts is ideal, if the accident is severe enough to twist the car or otherwise move the ROP's then there is a risk the seatbelt can be pulled tight or caused to go slack.

I guess it cant be to much of an issue due to the survival rate in the accidents that are recorded.

[Locutus]

a simple, controlled rollover test
http://www.youtube.com/watch?v=vGHzyNJ3-kI

I think for the road the answer is to drive carefully and not get in a situation you cannot control. The most important and sophisticated safety feature in any car is between the driver's ears.

just driving on a public road means sacrificing some of that control. my last mx5 was written off by an oncoming car turning right at an intersection and failed to see me. weather conditions were good, visibility was clear and neither of us were speeding. i took evasive action, but despite 3 empty lanes on my side of the road, there was nowhere to go. my car glanced off his, mounted a curb and narrowly missed a traffic light. if i had impacted the curb at an unfortunate angle, my car probably would have rolled over. Old Dude probably has a similar story to tell.

One thing I wonder about with the type of ROP's we all use is if the mounting to the seatbelt mounts is ideal, if the accident is severe enough to twist the car or otherwise move the ROP's then there is a risk the seatbelt can be pulled tight or caused to go slack.

it is far from ideal. i think in NSW at least, these ROPs can technically be defected for this reason.

[Alex]

No rollbar here but it didn't look great
viewtopic.php?f=18&t=17652

Also I believe bigdog was helped out by his but not in a rollover, you can read through the whole thread but these 2 posts should be enough
viewtopic.php?p=328242#p328242
viewtopic.php?p=329313#p329313

[Caffeine]

No rollbar for me.

A rollbar that would offer me protection in a rollover, without increasing my risk in any one of plenty of other types of accident, would be so tall it would prevent the roof from closing.

Having said that, I plan on getting a twin hoop bar in the future, as I want to install harnesses for track work. It looks to sit far enough away from my head as to not pose an increased risk in an accident.

[RawSouth]

After seeing an MX5 roll, and then resting on the top of the seats with the A pillar crushed, I bought a BD bar and had it installed within days.

Thank god no one was hurt, but it wasnt pretty.

I also think it cant hurt if you get rear-ended by a 4WD, especially those with lift kits and roo-bars.


Just my 2.2c (GST inclusive)

[Mr Morlock]

Road conditions are very different to race tracks and authorities may stipulate a roll bar for that environment- it does not follow that safety on a track equate to the same on the road.

If roll bars really add safety to an MX5 then why has the manufacturer never fitted one as standard ( 20+yrs) or as a optional extra? Mazda along with any other reputable manufacturer engineers a total car and is obliged to do extensive testing. The car is designed for everything to fit as a integrated design and a non standard roll bar immediately introduces a hard metal object in a very tight compartment.

The roll manufacturers make strong and probably well engineered roll bars but they do no crash testing and offer no test data related to the car- my contention is that the bar is not questionable but what it does in the vehicle in complex crash situations not necessarily roll overs is another thing. An individuals experience of an accident or watching something on u tube does not equate to scientific testing and any given accident is not going to be replayed with a bar in or a bar out. A roll bar in close proximity to a drivers or passengers head is in my view potentially dangerous - you have no control of your limbs in a crash situation.

Real life MUARC data rates the MX5 very well - if the vehicle rated very poorly in crash tests I would not own one and if safety is the concern then later model cars offer best protection.

Ultimately one can decide on whether it is a good idea for a road car but you will be doing it without any testing by recognised authorities.

[bigdog]

Your logic still escapes me Mr Morlock. The fact that a manufacturer chooses not to fit a safety device does not mean it is not necessary. ABS and airbags are proven safety devices that are not fitted to many vehicles simply to save the manufacturer money. The NC is fitted with integral ROPS, presumably because Mazda thought it was necessary. Perhaps the NA and NB missed out on ROPS to keep their cost down? The pictures already posted on this thread show what happens to an MX-5 in a rollover, with and without ROPS. The risk of head or body impact on the bar is present, but mitigated by padding, and it is just as likely as impacting the unpadded windscreen pillars/surround, or steering wheel in an NA.

The issue of driver head height in relation to ROPS height is significant in a small number of cases - most people are not taller than the ROPS. I am taller, but as I have stated elsewhere, I have watched tall drivers escape unscathed from rollovers where they were taller than the ROPS, and the ROPS played a major role in protecting them. Without helmets they would no doubt have suffered injury, but without the ROPS they may well have been killed. In a road car this is more problematic as we don't wear helmets, but again I feel the benefits outweigh the disadvantages.

The issue of mounting to the seatbelt post on an MX-5 seems over rated - this is the strongest point on the car, and the bar construction (MX5+ & BD) would seem to my eye to add to that strength by bracing it in several directions. Indeed, NAs had a factory brace that mimics the ROPS brace between the towers.

If I could handle the inconvenience I would fit a 6 point harness and race seat to really make the most of the ROPS safety advantage. All of these things involve compromise and perceived risk. Ideally Mazda would build a car with an integrated full cage, race seats and harnesses ala some of the current Ferrari/Lambo etc supercars. The reality is they can't afford to, so if you want these features you have to DIY.

[Old Dude]

Road conditions are very different to race tracks and authorities may stipulate a roll bar for that environment- it does not follow that safety on a track equate to the same on the road.

If roll bars really add safety to an MX5 then why has the manufacturer never fitted one as standard ( 20+yrs) or as a optional extra? Mazda along with any other reputable manufacturer engineers a total car and is obliged to do extensive testing. The car is designed for everything to fit as a integrated design and a non standard roll bar immediately introduces a hard metal object in a very tight compartment.

The roll manufacturers make strong and probably well engineered roll bars but they do no crash testing and offer no test data related to the car- my contention is that the bar is not questionable but what it does in the vehicle in complex crash situations not necessarily roll overs is another thing. An individuals experience of an accident or watching something on u tube does not equate to scientific testing and any given accident is not going to be replayed with a bar in or a bar out. A roll bar in close proximity to a drivers or passengers head is in my view potentially dangerous - you have no control of your limbs in a crash situation.

Real life MUARC data rates the MX5 very well - if the vehicle rated very poorly in crash tests I would not own one and if safety is the concern then later model cars offer best protection.

Ultimately one can decide on whether it is a good idea for a road car but you will be doing it without any testing by recognised authorities.

Whilst I agree Mr M that there has been no recognised testing by authorities on Roll Bars, it is interesting to see the number of manufacturers that are adding them to their vehicles, Mazda have the bars in the NC and although it isn't called a protection device, why add another obstruction if it has little benefit? BMW I believe list theirs in the Z4 as a safety device,as do some other manufacturers.
I chose the MX 5 plus bar as it sits further back like the NC so is less likley to injure the occupant in other crash situations, and having seen how easy some roll overs occur, I believe that most people seem to think that you have to be driving quickly on a race track.

Of the three that I have seen only one was at 100kph on the freeway when the driver lost concentration in front of me approaching a toll gate and ran into the metal side rail on the freeway rode this up and flip over. The other 2, 1 in which I was a passenger, was stationary almost and the cars were T boned, through other drivers running red lights or not paying attention.

After having been involved and seen how easily Roll overs can happen, I would not take the risk of driving a convertible, without some sort of roll over protection.

I remember in the early days of seat belts, how they were not compulsory but people still added them as a safety device to their cars, even though Volvo had them in their cars since 1959, they were not compulsory in Australia until 1969 and that was only the front seats, until 1971 when it was compulsory for all seats to have them. There were a lot of injuries by seat belts until the automatic retractors became compulsory in 1975 but they were still used as they saved lives.
Even modern cars like the VW EOS has roll over protection that is deployed in the event of a roll over detection, indicating that manufacturers are also aware how easily rollovers can occur.

I think it will only be a matter of time before, roll bars as well become standard in convertible cars.

Cheers
Dale

[Pamex]

FIrstly: I have an MX5 Plus in mine. I deffinitely would not drive mine without one. Mine has ample padding and sits back from my head, as I'm of average height, with a seat that gives me a lower seating position as well, so I'm well away from the bar in an impact.

There has been a few people that have said they won't get one until there is a report compliled. The thing is, there never will be a report compiled. There are far too many variables AND there simply isn't the numbers of MX5 owners with roll bars to produce a report of that type. There is also no cost benefit for anyone to do something like this, except for the roll bar manufacturers who simply wouldn't be able to afford the outlay to conduct this. It is also very unlikely that MUARC will do a report, as the funding simply isn't there. Research, particularly university based, is a competitive industry, and a grant or other form of funding for testing components/cars that will be used by a large percentage of the population will always win out over a grant testing something that, quite frankly, most of Australia and the world doesn't care about. MUARC will never win a grant application or funding round to do testing on MX5 aftermarket roll bars, so don't hold your breath waiting for it.

As for testing by the authorities... it simply isn't possible. When we talk about roll bar protection on the forum, we're generally talking about bars for NAs/NBs. We're talking about 10 or 20 year old cars, with numbers that don't dominate the market or even come close, and then a small percentage of those numbers using roll bars... there are also simply too many variables in car histories as well... it's not like they're testing brand new cars. To ask for a report from the authorities on this actually boggles me as to your understanding of research into these areas. Testing for the NC you say? Once again... we simply do not have the numbers to justify a report AND to provide accurate research and reporting.

A better way to observe any benefits or not, is to look at testimonials of users and also have a look at CAMS docs on roll over protection, specs on those roll bars, etc. and make up your own mind.

Morlock, I am also failing to understand what you are saying about the track vs. street. Are you saying that on the street a roll over will hurt any less than on a track? Yes, you have a helmet on at the track... yes, you're going faster. But a roll over is still a roll over and can happen just as easily on the street given the right conditions. It doesn't mean you have a chance of being hurt less on the street...

[deviant]

Some interesting points of discussion raised Mr Morlock.

Purely guessing here but I would say there are a number of reasons Mazda did not fit any roll over protection until the NC:

Crash worthiness standards had never stipulated that roll over protection is required so it was never engineered in to the car, this is the same for any style of car produced over the same period.

They are not attractive and they compromise the ease with which someone is able to raise and lower the roof and they also compromise your rear view.

Different parts of the world have different criteria for road worthiness. In the UK you could have a daily driver with a full tower - tower roll cage like a rally car yet here in Aus getting a basic half cage on the road is marginal(and this varies from state to state!) so Mazda would not be able to do something different for every part of the world without a significant increase in costs.

Which MUARC data have you looked at? I do not have time for a thorough search but the data I saw showed early MX5's to be no more dangerous than cars of the same period. This either tells us that the MX5 was a safe car for the 90's or that 90's cars had little in the way of good crash protection, I would say the latter more than the former. I would not fancy being rear ended or t-boned by a modern car and especially not by a 4x4!

The reputable manufacturers of ROP do in fact do some testing. Brown Davis use Finite Element Analysis as well as physically building a roll cage and crushing it in a giant press.

Also keep in mind that CAM's ROP specs are FIA standard. The FIA do in fact build roll cages to their own specs and then test them to destruction including putting them in a car and crashing it. If you follow FIA and CAM's guidelines then the cage should be good.

Having said that there is a compromise with the half cage lots of us use. As you rightly point out they are designed to fit within the confines of the car which of course means the occpants are very close to it, the bar really does need to be properly padded even for regular road use.