Daddylonglegs
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| posted on 24/2/10 at 06:38 PM |
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Roll Bar
In my recent thread Danozeman said he thought the roll bar was high, what do
other guys on here think?
I tried to guage the height by sitting in the car and allowing for the extra for the crash helmet. Not sure now if I might have been over
conservative.
I also have some more 40mm tube I am going to use to brace the bar, but it is just a few inches too short so it might be an advantage to lower the bar
anyhow, not too much of a job.
I am 6' 4" BTW 
JB
It looks like the Midget is winning at the moment......
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omega0684
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| posted on 24/2/10 at 06:40 PM |
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i dont think your roll bar is too tall, but it will need reinforcing for sure!
I love Pinto's, even if i did get mine from P&O!
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eddie99
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| posted on 24/2/10 at 06:41 PM |
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Can you not lower the seats a bit. I'd say its a bit too high as well. Maybe with some structure it would be ok.
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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Miks15
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| posted on 24/2/10 at 06:44 PM |
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i think it looks to high, any pics of you sat in it with ahelmet on mabye?
a side view would be best
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MikeCapon
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| posted on 24/2/10 at 06:47 PM |
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Why do you want to lower the roll bar?
What are the consequences of too high a roll bar?
What are the consequences of too low a roll bar?
It needs to be at least high enough and no lower. Looks do not matter here. It's your and your passenger's lives you're talking
about.......
Other peolples opinions of the aethestics are very secondary IMO
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zilspeed
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| posted on 24/2/10 at 07:01 PM |
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The MSA blue book will give you some much more reasoned advice regarding the construction and indeed the height of your roll bar.
What it looks like, quite frankly, has nothing to do with it.
As you say, you're 6'4".
I'm 6'2" with a long back, consequently I don't properly fit a lot of open cars and it's difficult to build a car which
fits me and more normally proportioned people. I know this to be true as I was asked to be one of the guinea pigs for a clean sheet project
Guess what, you need a taller roll bar than a short aris.
So, check out the blue book and build to that standard.
Hopefully, Minitici or Procomp will be along soon to give more informed comment.
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ginger ninja
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| posted on 24/2/10 at 07:07 PM |
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I'm 6'2" and had a similar problem. The roll bar is a "standard" height and when sat in the car with a helmet on we
found the top of the helmet was level with the top of the bar. If you consider what happens when the car rolls, when upside down it is supported off
the floor by the roll bar and the chassis at the nose end. Drawing a line between these two points to represent the ground (we used a piece of
string), your helmet should be well below the string or it could end in tears !. To overcome this we added a second roll hoop at the scuttle (looks a
bit like a windscreen) and braced it off the original. Looks more business like and allows somewhere to mount a rear view mirror and side mirrors.
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RichieHall
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| posted on 24/2/10 at 07:43 PM |
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According to the blue book the drivers helmet must not cross a line drawn from the rollbar to a substantial structure of the car
http://www.msauk.org/uploadedfiles/msa_forms/bluebooks/10/160-195%20Competitor%20Safety.pdf
Hope this helps
Rust is lighter than Carbon Fibre!
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RichardK
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| posted on 24/2/10 at 08:47 PM |
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I calculated mine in a similar fashion and came to this: Me 6'5"sat in car with lid on, took string from vernier cam pulley to 3"
above my head to allow for strap slackness in the harness and carried on and thats where it ended up. Simples.
I don't care what people think, it my head!
Cheers
Rich
[Edited on 24/2/10 by RichardK]
Gallery updated 11/01/2011
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Daddylonglegs
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| posted on 24/2/10 at 09:01 PM |
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Thanks for some really good constructive input there guys 
I'm not over fussed about it 'looking' too tall, just being unecessarily tall. I totally agree that safety is paramount, and
thoroughly understand what the consequences of it being too short  . I think I'll go with the blue book line and see where that takes me. After
all, I'm sure I can get some longer 40mm tube if I need it, and what price safety?
Thanks again guys 
JB
It looks like the Midget is winning at the moment......
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stuart_g
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| posted on 24/2/10 at 09:09 PM |
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It really depends on how high your head and crash helmet if you are going to wear one is above the height of your seats. You ideally want the roll bar
to be taller than the top of your crash helmet.
MNR measured me in the seated position so they got the roll bar the right height.
http://www.eastangliankitcars.co.uk/
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austin man
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| posted on 24/2/10 at 10:23 PM |
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surely the taller it is the weaker it would be if you ended upside down. we all know its easier to bend a long metal bar opposed to a short one
Life is like a bowl of fruit, funny how all the weird looking ones are left alone
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RichieHall
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| posted on 25/2/10 at 02:36 AM |
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Isn't that a null point if your head hits the ground first?
Obviously there is a limit as to how low the seat can be, but with a cross brace and rear supports strength shouldn't be an issue, especially if
your using 38mm CDS or T45?
[Edited on 25/2/10 by RichieHall]
[Edited on 25/2/10 by RichieHall]
Rust is lighter than Carbon Fibre!
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Daddylonglegs
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| posted on 26/2/10 at 08:22 AM |
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I can't lower the seats any more, they'r already mounted directly to the cross members. And as already said, I will be adding some bracing
struts using 38-40mm tubing so I don't think the height will be an issue.
At the end of the day, the best result is to keep it on all 4 wheels at all times (well 3 of them at least)
It looks like the Midget is winning at the moment......
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