Haynes Forums  

Go Back   Haynes Forums > Haynes Roadster Forums > Chassis
FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
  #1  
Old 2nd September 2012, 10:51 PM
DaveyB DaveyB is offline
Senior Member
 
Join Date: Mar 2008
Posts: 141
Default roll bar

Hi could anyone tell me if it matters with IVA if my head sticks above the roll bar i purchased a roll bar from Ash a long time ago and recently have been mocking up my seats and harnesses and when sitting in the car i think my head is close to the top i am 6'6',don't want to start welding only to find it fails iva? and am i ok to bolt straight through the floor with the seat fixing bolts.
Any help would be greatly appreciated
Thanks
DaveyB
Reply With Quote
  #2  
Old 3rd September 2012, 02:28 AM
ozzy1's Avatar
ozzy1 ozzy1 is offline
Senior Member
 
Join Date: Jul 2009
Location: perth,australia
Posts: 760
Default

There is actually no requirement to have a rollbar at all for IVA.If you have one then i personally would want it to offer some rollover protection so it will likely need to be taller to offer this.I recall Spud was about 6'6" and had to have his made larger.
With regards to the seats i see it this way;if you have a steel floor welded in then bolt it through it.If you have an aluminium floor riveted on then i would put in support strips of 5mm across the 450mm width.
Reply With Quote
  #3  
Old 3rd September 2012, 01:32 PM
Davidbolam Davidbolam is offline
Senior Member
 
Join Date: Mar 2011
Location: Gosforth, Newcastle Upon Tyne
Posts: 856
Default

I have upgraded the strength of the bolts in my roll bar to M10. Does anyone know if any cars have passed IVA without rear stays. I haven't got them on mine. I was looking at the GBS zero and theirs seem to be more for cosmetic reasons as they bolt into an unsupported alloy rear panel.
__________________
Click to see my build photos on Flikr

http://www.flickr.com/photos/67112582@N03/

Saturn MX5 Based Chassis, Limited Slip Diff & 2.4 Quick Rack.

Build cost.... seems to be spending more on tools than car bits at the moment! (they will be handy in the future though).
Car iva'd and passed 15/08/2014. Finished weight 572kg.
Reply With Quote
  #4  
Old 3rd September 2012, 08:00 PM
DaveyB DaveyB is offline
Senior Member
 
Join Date: Mar 2008
Posts: 141
Default

Thanks for the reply, do you think it will be ok to weld some additional 50 mm tubing to the bottom of the roll bar to archive some extra height without ruining the integrity of the roll bar from its original form?
I was thinking of placing the seats on some 5mm plate could I just drill and tap the holes for fixing them or should I still drill straight through.
Thanks again for the help
DaveyB
Reply With Quote
  #5  
Old 3rd September 2012, 08:33 PM
flyerncle flyerncle is offline
Senior Member
 
Join Date: Mar 2008
Location: gateshead,near cobbly bit of A1 North
Posts: 3,188
Default

If you must lengthen it,it would be sensible to strengthen it with some tube inside it and weld all three parts together and also make a hole in the mounting plate and place the tube through and weld underneath too.
__________________
Cost : Little as possible.
Thanks : To those who by their generosity my build has progressed.
Its a handmade sports car not a flaming kit car !!!


If at first you dont succeed,avoid skydiving...

No parachute require to freefall,only if you want to do it twice.
Reply With Quote
  #6  
Old 3rd September 2012, 08:39 PM
PorkChop PorkChop is offline
Senior Member
 
Join Date: Jul 2011
Posts: 394
Default

Quote:
Originally Posted by DaveyB View Post
Thanks for the reply, do you think it will be ok to weld some additional 50 mm tubing to the bottom of the roll bar to archive some extra height without ruining the integrity of the roll bar from its original form?
Personally I wouldn't. The roll bar is there to help protect your bonce. IMO, if the welding is ever so slightly off, you've introduced a potential fatigue point if the worst was to happen.

WRT rear stays, I would incorporate some into the design. If you look at any functional roll cage (be it in a sevenesque or saloon car) you have a pair of functional stays.

Yes, you could theoretically have a single hoop rollbar. However, it would have to be substantial to be of as much use IMO.
Reply With Quote
  #7  
Old 3rd September 2012, 09:02 PM
mgglep's Avatar
mgglep mgglep is offline
Senior Member
 
Join Date: Apr 2011
Location: leicestershire
Posts: 212
Default

I agree if god forbid you flipped it is the only thing that would keep you alive the stronger the better IMO I might have a friend who has a hoop that is longer its 50mm tube and it's nicely bent he was the guy who lent me his Cnc bender for my bar
__________________
17.07.10 "Now i know the meaning of life"
My Build pics
http://www.flickr.com/photos/67605695@N04/
http://www.flickr.com/photos/97412063@N08/
Reply With Quote
  #8  
Old 3rd September 2012, 09:48 PM
DaveyB DaveyB is offline
Senior Member
 
Join Date: Mar 2008
Posts: 141
Default

Hi well thanks for the replys I did wonder about modifying the bar and it still being suitable.so thanks for the help , I think I will have to consider a completely new bar. I will concentrate on getting the seats in position and will then be able to work out exactly what height I will need. Thanks again
DaveyB
Reply With Quote
  #9  
Old 9th September 2012, 08:17 PM
Oscar Oscar is offline
Senior Member
 
Join Date: Sep 2010
Location: Wincanton
Posts: 202
Default

Hi Davey,

Time to be really cheeky

If you do decide to go for a bespoke, made to fit rollbar, does that mean you'd have a book spec one up for sale?

I always think it's good to get in early on any cheeky deals
__________________
Photos of the project so far:

http://www.flickr.com/photos/oscarss/sets/
Reply With Quote
  #10  
Old 22nd September 2012, 09:19 AM
DaveyB DaveyB is offline
Senior Member
 
Join Date: Mar 2008
Posts: 141
Default

Having thought about it a little perhaps won,t sell, I was wondering
About putting a tube like a sleeve around the 50 diameter
Have seen some 60 mm tube with the right bore I could extend it welding the outside and inside only need to extend about 2/3 inch will it matter if the outside diameter is a little bigger where the cross bar goes for the seat belt positions it won't be much if you get my drift.

Thanks
DaveyB
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT +1. The time now is 09:08 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.