Roll bar, yay or nay?

[Munter]

pbirkett said:

varsas said:

Might want to discuss this with your insurance company. Anecodal evidence suggests insurance companies/police don't like roll cages in road cars (roll bars are probably a different matter.)

I wouldn't drive a roll cage equipped car without a helmet.

Yes, being taken up the oxo tower by the insurance company was a concern.

It's not too bad with the right companies. Nothing mainstream will touch you so forget comparethemeercat.com. And go to the usual suspects recommended on here.

Me 30 1 claim a few years ago. Her 25 driving 3 years. £420ish I seem to remember. That's roll bar and suspension mods.

For those wondering how strong the MX5 screen is:
http://www.youtube.com/watch?v=vGHzyNJ3-kI

[pbirkett]

The Wookie said:

pbirkett said:

To be fair, I tend to give myself a good margin of error on corners, so I do see what you're saying - I never drive at the limit on a corner, but even so, I've heard of folks who have still managed to roll a car without driving at the limit.

You can easily think too much about it, but you've just got to go with the balance of probability

So does that mean you think I should or shouldn't?

I suppose its quite unlikely to happen, but certainly not impossible.

[The Wookie]

pbirkett said:

I imagine headbutting it would hurt. A lot.

It might, or it might not!......

Put it this way, I went backwards into an armco at speed while racing my caterham and spanked my head on the right rear cage upright. I was wearing a good quality helmet and I was seeing spots a couple of hours afterwards. If I'd had that accident without a lid on I'd be dead without a shadow of a doubt. You could have a similar sort of accident if you lost the back end on a motorway.

I prefer the look of those hoops if they're structurally mounted, you're much less likely to biff them with the headrest directly between you and the bars

[JR]

heightswitch said:

slideways said:

heightswitch said:

slideways said:

heightswitch said:

slideways said:

[

APMAUTO said:

slideways said:

I would like to look at getting a full rollcage for the Chimaera, the sort of thing that Cerberas have but one that is not too intrusive in the cabin. i have done a search and and found a couple but to be honest they look a bit unwealdy.
so has any one done any reasearch into this subject?
Pictures would be great if you have them.

try speaking to andy robinson at www.robinson-race-cars.co.uk one of the best fabricators in the uk did our cage in the gt cup cerbera and also made suspension parts we needed,heavily into drag racing so you wont find safer or better!

regards andy(APM)

Thanks Andy i will take a look.

I hate posts like this one.

are you going to race?
Are you going to use 4 / 6 point harnesses and a helmet?

a cage has to be built to a spec and generic minimum design then certified. This is a lot diferent to putting some tubes in a road car that won't save your life in a crash and may well end it prematurely.

Andy robinson is one of many good fabricators out there who can install a custom made cage for you but a cage should always be used in conjunction with the other 2 items. You need to be very specific with what you mean by "intrusive"

I dont see why you would hate posts like this??
the whole point of the post is to discuss options, the fact that i stated rollcage should tell you i'm not after the usual bar that may not stand up in a roll as the screen could collapse,
i will want to track the car but probably not full on race as it is a road car
and will use a 4 point harness,
the comment on intrusiveness was aimed at still being able to get in and out of the car without being hudini

What I mean is that a road car with a cage installed and driven by a bloke without a lid is more likely to kill its occupant in a crash than a car without a cage. cages are a system designed to work with a driver that cannot move about and also a driver with a lid protecting his head from damage. if you are building a compromise car which is part road and part competition then fair enough which is what I meant by being desctiptive of "intrusive" A cage built to look neat in a road car may not actually be very good at what a cage is supposed to be installed for in a race car.

How many road cars have you rolled?
As an alternative thought how many times have you been involved in a rear end shunt minor bump etc but remained in the upright position. Its all well and good building the compromise car for the odd track day but if you drive said car on road more than you track it then you should be considering whether you are putting yourself at greater risk due to the imbalance in frequency of track / road driving?

All fair comments! a friend of mine sustained some brain damage after a track day, driving home the steering went and he came off the motorway and rolled down a bank the hit a tree he was obviously not wareing a helmet on the way home, it was in a caterham with a full cage and harness.
the cage undoubtedly saved his life but could also have killed him in the process.

where i am coming from is something to stop total collapse if the worst should happen but not kill you in a normal accident senario. if that makes scence?

My recommendation is not to fit one.

If you are tracking your car you are essentially driving alone on a track and passing people in a safe controlled manner. All your cage is going to do in your road car is make you slower because they are heavy.

A cage in a chim or griff which retains the roof will certainly be very close to your head. a door bar will be very low to allow you access which also means it will have diminished purpose. top rails built to remain in a roof will skim your tempral lobe. you will find that any decent fabricator will refuse to make what you want. because what you want will not save your life in a crash

My view is that you have a road or a race car but not both.

A road car with compromised race bits is possibly dangerous.
A road car with a fully trimmed cage built into the structure would be prohibitavely expensive

at the end of the day it is your car and you are free to do what you want but in my opinion a compromise cage in a compromise car will only do both things worse than going one way or another.

I know Andy Race has a road registered race griff so he would be your first call to look at what he has done. i am pretty sure he will have a similar opinion to mine though that the use of the car is foremost.

A good friend of mine had to examine a TVR to assist the police after a survivable rear end shunt cause the death of the Drivers daughter who was a passenger at the time of the accident. The cause was the daughters head being thrown back into the cage.

This is why I have such strong opinion on race cages and road cars which become neither one thing or another.

[Seez]

I think on balance of probabilities we are saying 'nay'!

[pbirkett]

Munter said:

For those wondering how strong the MX5 screen is:
http://www.youtube.com/watch?v=vGHzyNJ3-kI

Thats actually quite disturbing

@ JR - thanks for the post... these posts have certainly put me off a bit.

I think if anything, I think I'd go for a strong hoop style bar which I couldn't headbutt or a strong style bar... or perhaps just try not to roll it

[GravelBen]

pbirkett said:

GravelBen said:

Yes from me, I've got one But I'd say no to a full cage if anyone suggests that.

Mine is a 4-point bolt-in job, main hoop mounts to the floor behind rear seats and stays go back to the chassis rails just in front of the rear struts.

It also tightens up the chassis quite noticeably which is nice

Which one do you have?

It only has a small Japanese label on it (which I can't read) but photos I've found of identical looking units were made by Cusco/Safety 21.



It looks quite close to the seats in that photo but I think its just the angle, you'd have to be well out of the seat (or very tall, I'm 5'10) to make contact.

[Tangent Police]

OK. I gathered that adding a roll "cage" to your car upped the premium by 35%. Not sure if this is right, but it amounted to my mini costing £135 FC. I imagine there will be a similar penalty for hoops.

If you have a good off on the soft stuff, hoops will dig in anyway. I'd spend the extra money on getting the centre of gravity lower.

I purely fitted a cage to stiffen the shell up and improve handling, rather than be something for cartwheel protection. Unless you are track racing, the chances of you doing a big roll in a low sportscar are virtually squat.

Learn to crash properly

[Incorrigible]

The Wookie said:

You could have a similar sort of accident if you lost the back end on a motorway.

This is assuming you're on a motorway that looked a bit like Blanchimont corner and you're wheel to wheel with another car at 130 mph

[JR]

GravelBen said:

It looks quite close to the seats in that photo but I think its just the angle, you'd have to be well out of the seat (or very tall, I'm 5'10) to make contact.

Well out of the seat? You mean like the car turning over so that the combined gravity and centrifugal forces throw you towards the roll bar?

[Tadite]

I think you should go to the many Miata Spec racing forums. This is a common topic for people who duel-use their cars. The most common choice for the NA/NA is to go and get a roll bar. I don't know what people are doing about the NC. I wonder if they upgraded the windshield on it?

Here are some Forums:

http://www.specmiata.com/
http://www.mazdas247.com/forum/index.php

Full Cage:
http://www.miatacage.com/

Roll Bar:

The most common seems to be Hard Dog with lots of different styles and specs.

http://www.flyinmiata.com/index.php?dept=91
http://www.bethania-garage.com/hardbar_sport.htm

[GravelBen]

JR said:

GravelBen said:

It looks quite close to the seats in that photo but I think its just the angle, you'd have to be well out of the seat (or very tall, I'm 5'10) to make contact.

Well out of the seat? You mean like the car turning over so that the combined gravity and centrifugal forces throw you towards the roll bar?

That could do it, yes. But I'd prefer to chance cracking my head than getting squashed down to door level, which is the non-rollbar option in the circumstances you mention With the roof up one of its bars gets in the way anyway so I'd just hit that instead.

Its probably more likely to occur on track, in which case I'll be wearing a helmet anyway. However I do intend to get some bucket seats for it before too long which should give a lower driving position and a bit more headroom.

[heebeegeetee]

If you think that your style of driving is likely to lead to an accident - should you be driving?

If you hit your head hard on one of those roll bars, you'll suffer a serious head injury, possibly fatal or debilitating. In a nasty shunt you can be flung all over the place.

I've been on track days where helmets were only compulsory if you had rollbars/cage, to protect you if you hit your head on the bars/cage.

[GravelBen]

heebeegeetee said:

I've been on track days where helmets were only compulsory if you had rollbars/cage, to protect you if you hit your head on the bars/cage.

Really? I've never been to a trackday where helmets weren't compulsory, and at least one track day organisation I know of won't let convertibles like MX5s run without roll protection.

[heebeegeetee]

GravelBen said:

heebeegeetee said:

I've been on track days where helmets were only compulsory if you had rollbars/cage, to protect you if you hit your head on the bars/cage.

Really? I've never been to a trackday where helmets weren't compulsory, and at least one track day organisation I know of won't let convertibles like MX5s run without roll protection.

They probably are all compulsory now, but they didn't used to be. But i've done more than one where only rollbar/cage fitted cars had to wear helmets, and full face at that, and that was simply to protect the occupants from the cage - you don't need to crash to smack your head hard on them and they are very unforgiving.

[GravelBen]

I expect they are, I certainly wouldn't want a full cage in a road car. But this thread is about a bar or half cage behind the seats in a car with no other roll protection, which I think is a different story.

[heebeegeetee]

GravelBen said:

I expect they are, I certainly wouldn't want a full cage in a road car. But this thread is about a bar or half cage behind the seats in a car with no other roll protection, which I think is a different story.

I accept that, but in a crash your head can ricochet around like a punch ball, and if you smack the bar behind your head it can kill you or seriously hurt you.

Personally, i'd choose to not have a shunt in the first place, and trust me, i like to hoon as much as the next man.

[GravelBen]

heebeegeetee said:

...Personally, i'd choose to not have a shunt in the first place...

Don't we all... I believe some folk call them 'accidents', I think this is because they tend to happen unintentionally.

Personally (especially with track use), I find the roll protection and extra chassis stiffening well worth the small risk of flailing my head backwards over the top of the seat and hitting the bar in an accident. at least my head won't go back far enough to break my neck. Though as said before, good buckets (like the OP has) will make this even more unlikely.

Either way, you pays your money and you makes your choice

[SClarke]

The obvious all-encompassing sensible anwser is to fit a full cage and then always wear a helmet. Job done.

[900T-R]

The Wookie said:

I prefer the look of those hoops if they're structurally mounted, you're much less likely to biff them with the headrest directly between you and the bars

Exactly my thinking - I'd say the goal post design is not appropriate for a road car (unless it's an aeroscreened Seven in which case you'd wear a helmet, anyway).