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Roll Bar height
bpgoa - 23/5/07 at 03:54 PM

how high does the roll bar behind your head come up from the top of the rear suspension mount plates....

I've found a tube bender who's half the price of a roll bar... but i got to give him a drawing..


worX - 23/5/07 at 03:58 PM

It appears that the manufacturers don't all do it a regulated height.

The pinnacle of this difference shown mostly in the fact that MNR measure people for their roll bars so that they are specifically safe.

Take Agriv8's roll bar for instance - some say it seems a tad high, but he know it was made to measure and therefore most safe.

I am happy to measure mine for you, and as we are (IIRC) roughly about the same height I would think you would be able to gauge whether this was suitable for you or not!

cheers,
Steve

Oulton small
Oulton small


[Edited on 23/5/07 by worX]


kb58 - 23/5/07 at 04:04 PM

Think of it this way. Imagine being belted into your car, and having the car suspended 3 meters above the ground - upside down. Now let the car drop with you in it. Will your head hit the ground? If the answer's yes, the bar's too low.

For starters, draw a line from the front nosecone to the top of your helmet. Now extend this line back further until it crosses where your roll-bar will go. That's the minimum height. You will need it taller than this to account for the nose getting crunched down, and for you rising up out of the seat in a rolling accident.

[Edited on 5/23/07 by kb58]


bpgoa - 23/5/07 at 04:05 PM

Thanks....


Agriv8 - 23/5/07 at 04:09 PM

quote:
Originally posted by worX
It appears that the manufacturers don't all do it a regulated height.

The pinnacle of this difference shown mostly in the fact that MNR measure people for their roll bars so that they are specifically safe.

Take Agriv8's roll bar for instance - some say it seems a tad high, but he know it was made to measure and therefore most safe.

I am happy to measure mine for you, and as we are (IIRC) roughly about the same height I would think you would be able to gauge whether this was suitable for you or not!

cheers,
Steve

[Edited on 23/5/07 by worX]


Thank you sir you put that in the most polite way possible.

Most people just laugh and go 'that looks stupid' ( I hope they are pointing to the roll bar and not me ) but I am happy in the knowledge that my head is out of the way ( taking into account the contact points ( roll bar / engine ) if it does go over.

<--------------

ps thats me in my MNR with the Supper lanky Size roll hoop.

yust a point while I am posting - I am sure you realise that you get what you pay for - what material is he making it out of ?

Kind Regards

Agriv8


bpgoa - 23/5/07 at 04:09 PM

Nice.... happy thoughts...


quote:
Originally posted by kb58
Think of it this way. Imagine being belted into your car, and having the car suspended 3 meters above the ground - upside down. Now let the car drop with you in it. Will your head hit the ground? If the answer's yes, the bar's too low.

For starters, draw a line from the front nosecone to the top of your helmet. Now extend this line back further until it crosses where your roll-bar will go. That's the minimum height. You will need it taller than this to account for the nose getting crunched down, and for you rising up out of the seat in a rolling accident.

[Edited on 5/23/07 by kb58]


bpgoa - 23/5/07 at 04:12 PM

75mm x 2mm CDS... main hoop..

50mm x2mm CDS diag / back struts/ front strut






<--------------

ps thats me in my MNR with the Supper lanky Size roll hoop.

yust a point while I am posting - I am sure you realise that you get what you pay for - what material is he making it out of ?

Kind Regards

Agriv8



worX - 23/5/07 at 04:20 PM

LOL
I had noticed!!!
and in your defense "most people" don't always know better!
the only difference I would of made in your case is the same "addition" that I had put into mine!
the forward diagonal:

avatar
avatar

quote:
Originally posted by Agriv8
Thank you sir you put that in the most polite way possible.

Most people just laugh and go 'that looks stupid' ( I hope they are pointing to the roll bar and not me ) but I am happy in the knowledge that my head is out of the way ( taking into account the contact points ( roll bar / engine ) if it does go over.

<--------------

ps thats me in my MNR with the Supper lanky Size roll hoop.

yust a point while I am posting - I am sure you realise that you get what you pay for - what material is he making it out of ?

Kind Regards

Agriv8


[Edited on 23/5/07 by worX]


Agriv8 - 23/5/07 at 04:20 PM

quote:
Originally posted by bpgoa
75mm x 2mm CDS... main hoop..

50mm x2mm CDS diag / back struts/ front strut




<--------------

ps thats me in my MNR with the Supper lanky Size roll hoop.

yust a point while I am posting - I am sure you realise that you get what you pay for - what material is he making it out of ?

Kind Regards

Agriv8



Sounds like you have found a good deal !!

regards

Agriv8



[Edited on 23/5/07 by Agriv8]


bpgoa - 23/5/07 at 04:21 PM


worX - 23/5/07 at 04:24 PM

does this mean you want me to measure it Adrian?

quote:
Originally posted by bpgoa
Thanks....


bpgoa - 23/5/07 at 04:25 PM

Steve,

after the trip around Stonleigh are in your car... i've decided to make that bar removable... just in case i get the opurtunity to scare the sh!t out of the mother in law!!!


bpgoa - 23/5/07 at 04:27 PM

you don't fancy measuring your prop shaft lenghts as well do you.... don't think i can mount my engine as far back as you have yours... but wouldn't mind doing the comparison thing...


cheers


A..


worX - 23/5/07 at 04:31 PM

My front diagonal is actually removable believe it or not - I wanted it that way for the same reason you do - but every person who's been in it really likes it there!

Do you mean my prop or drive shafts? I take it since you mentioned engine position you mean Prop shaft?

If so this might be a bit tricky as I have a fully enclosed floor and don't really have a way to get to it for an accurate enough measurement!

I will have a go though!


worX - 23/5/07 at 04:35 PM

It is 365mm to the bottom of the tube and 415mm to the top (which is a relief cos it's 50mm thick ).

I will try and measure the prop for you tomorrow...

Steve


bpgoa - 23/5/07 at 04:37 PM

just looked on your website at the pics... going to copy the way the bars go together...

don't wory about the prop shaft measurements... sounds like a mision... will ask birich.. as he's mounted the same engine as i have...


bpgoa - 23/5/07 at 04:39 PM

quote:
Originally posted by bpgoa
just looked on your website at the pics... going to copy the way the bars go together...

don't wory about the prop shaft measurements... sounds like a mision... will ask birich.. as he's mounted the same engine as i have...


bpgoa - 23/5/07 at 04:39 PM

quote:
Originally posted by worX
It is 365mm to the bottom of the tube and 415mm to the top (which is a relief cos it's 50mm thick ).

I will try and measure the prop for you tomorrow...

Steve


worX - 23/5/07 at 04:41 PM

Don't copy them exactly!

I asked Mark (of MAC#1 several times ) for the front diagonal to be placed closer to the drivers side so that when it actually run at head height it was in the middle (or actually a tad closer to the pax) but they put it in the middle of the roll bar, SO, so that it runs really close to the pax...

I also asked for it to be placed closer to the driver to make the most of the extra triangulation of the open cabin..................


bpgoa - 23/5/07 at 04:46 PM

given that I realy am going to directly copy the height of the bar (because yours looks and is a sensible height for me - and i'm not allowed to pick up leggy blondes) how far would you have had it offset from center towards the driver?


worX - 23/5/07 at 04:48 PM

just rushing out!

will post a measurement on here after the 17.45 start spiderman3!!!!!!!!


bpgoa - 23/5/07 at 04:51 PM


RK - 23/5/07 at 06:21 PM

While we are on the subject..

What do people think of a full cage with side protection, for the road? I don't want a minor accident to turn into a fatal one, especially if I'm going to be involved.


JoelP - 23/5/07 at 07:11 PM

a full cage is an excellent idea tbh. I dont think upside down is going to be fun however good a plain rollbar is, far too much chance of catching a bush in the face, or worse.

The weight penalty isnt as bad as it could be if you work the cage in well as it adds good strength.


kb58 - 23/5/07 at 07:16 PM

Just be aware that slamming your head into the side-bar isn't going to be much fun. In fact, if the car slides into a dirt embankement, the side-bar might be what kills you instead of hitting the dirt. Some serious padding - if not a helmet - would be in order.

[Edited on 5/23/07 by kb58]


RK - 23/5/07 at 08:24 PM

I had thought of that. I had a bad accident a couple of years ago actually, where I was hit in the rear quarter panel, and the hit my head took onto the Headrest, gave me a concussion, post-concussion syndrome etc. Not fun and the pills cost a fortune.


JoelP - 23/5/07 at 08:31 PM

quote:
Originally posted by RK
the pills cost a fortune.

what you need is a free national health service!


Alan B - 23/5/07 at 08:40 PM

quote:
Originally posted by JoelP
quote:
Originally posted by RK
the pills cost a fortune.

what you need is a free national health service!


I thought Canada did?

Or freeish at least...


RK - 23/5/07 at 09:12 PM

Not for drugs. Anything else, yes. For example, when my hand was broken in two from a mountain biking accident, it was repaired the next day!

Some oldsters can be covered for drugs by their provincial plans (Quebec does it for example), but not for tax paying people of a certain age.


JoelP - 23/5/07 at 09:24 PM

ah well, you still have to pay for drugs round here too...

(poor joke, i mean 'recreational' ones...)


C10CoryM - 24/5/07 at 04:01 AM

Have a look at the SCCA or FIA rulebooks.
SCCA is online and has a good write up on rollbars/cages.
I know a rollbar has to be 2" above the helmeted head for SCCA. It works for me because that gives me the minimun required angle between the main hoop, and the down tubes (30 or 35degrees, I forget).

Im of the mind that rollbars and knee bars are best for the street. And full halo/cage is best for track where you have a helmet, GOOD padding, and a neck protector of some sort. No point caving your head in on your "safe" roll cage on the street.


worX - 24/5/07 at 11:11 AM

Hi again Adrian,

I have estimated where I think the front diagonal should start.

The one I have is nearly in the middle, and I think that to get the diagonal to be Centralised at head height it would need to be moved over around 90mm, but to err on the side of caution (to give the driver a touch more room than the passenger) I would suggest around 65mm toward the Driver side!

All this can be checked however just to ensure it is still correct for you, by just doing a mock up. You could use welding/brazing rod/wire etc for this?

With regard to Cory's post, if you want to make it comply with that SCCA Reg. My NON helmeted head is about 65mm below the Bottom of the roll bar (50mm tube as above) and therefore helmeted head is probably 25-30mm below the bottom of the tube.

I don't know any of the rules and regs of the SCCA or FIA, but at least you have a (sort of) datum point if you want to find out yourself!

cheers,
Steve.

edited to add: PS - Spiderman 3 was a big pile of poo (of the poo-est kind too!) and thats coming from a pretty avid Spidey fan!

[Edited on 24/5/07 by worX]


bpgoa - 26/5/07 at 09:05 PM

as per spec, but changed to 50mm cds..

will let everyone know the cost ... later


t.j. - 27/5/07 at 10:09 AM

quote:
Originally posted by JoelP
ah well, you still have to pay for drugs round here too...



Drugs are freely excessable around here if that's the problem. But i'm sure it won't make you happy on the long run.

[Edited on 27/5/07 by t.j.]