Rollbar?
 

Hi just a quick ? Does the rollbar have to be constructed out of one continuous length or can you use thick wall pipe and weld elbows

Arfon

Not sure on the IVA side but much stronger if in made in 1 piece.

One piece is stronger I intend to have mine done out of 75mm cds and bent using a friends hydrolic mandrel bender but made to my own design but not sharing that just yet

Just bought the tube to do mine, borrowing a clarke 12ton hydraulic press off a mate to do the bends, I've been told to pack the tube with wet sand prior to bending as this should prevent creasing... not sure if it will work but nothing to lose. Using 50mm x 3mm wall for the main hoop and 38mm x 2.6mm for cross bar and rears supports.... good deal on ebay at the moment for 38mm tube think it was £20 delivered for 2M and discount if you order more.. ITEM# 160148565771

Rapid... I'll post a pic once done (if it looks ok :D , if it looks crap I'll sit in the corner and sulk:( )

A mate of mine owns his own fabrication shop so he would bend them for me but I have a couple of ideas bouncing around in my head about the design. One of the designs would be easier to fab in sections rather than trying to do it in one complete length

Arfon

The sand filling worked for me.
Just take your time and try not to bend to tightly to quickly and use the outmost pivot rollers.

My mate uses the wet sand method too but he says make sure its well packed in there

My cage will be in 3 pieces with lots of angled fishmouths to cut and a couple of quite tight bends but I got my mate bending mine for me or I may just buy I normal one and make do

Remember they are funny about double bends too! ;)

I know may have to do the special one post iva like everything else that is in my head

I think that only relates to the rules as laid out in the MSA blue book for racing. If it's only going on the road or track days you can design and make it out of what ever you want. I remember seeing a seven at the Stafford show a few years back that had a cage made from 1.6mm stainless exhaust tubing all polished up.

Could be wrong but there is no requirement in the IVA manual for any roll bar to be fitted and it is only used (apart from being a roll bar)to mount the seat belt mountings,an adittion to Talons comment on the Blue books reqiurement's in motorsport is for a rear protection to be fitted, its a good idea to fit a rear bar to the Roadster rear stay's.

So if I am reading this right i should be ok going ahead and using weld elbows, preped, rooted with tig and then caped and dressed clean

Arfon

Sounds like a plan:D

Maybe mate how is the build coming on have you had your loom yet

Arfon

Yep.Its a work in progress. Got the headlamps up and running,ignition wired in and hoping to fire up soon.WATCH THIS SPACE EVERYONE(but dont hold your breath:o )

well just had a go at bending my rollbar... complete failure!!!! Packed it with wet sand, used a 50mm die etc etc

I was using ERW tube and I read somewhere to have the seam halfway between horiz and the bottom of the die. Tried to bend the tube with the rollers in nice and snug and the begger kinked staright in half like a coke can.

After much cursing and declarations of selling the stupid car etc etc I reconvened back to the garage looking at my £35 that I just put in the bin and thought well may as well try all other possible varients...

Tried it with the seam vertical and rollers untouched, kinked
Tried with rollers out on the last 2 holes (as I read that somewhere) seam horiz - kinked
Same set up but seam rotated to the halfway position - kinked
Tried with seam on the top - kinked

So I give up... stupid tube.... stupid tube bender :mad:

Not a good start to a day working on the car

If your using the open formers that come with the clarke 12t bender it does'nt matter what you do with the tube it will always kink or go flat. You need to use high sided formers like the hilmor conduit type, how ever the biggest hilmor former is 42mm. You still get minor kinks that are 1mm deep but can be over come with a little filler and paint.

well i guess that's a little comforting that I didn't completely screw it up but I think i best leave it to the guys with the proper kit

too expensive to keep experimenting, think i'll try and find someone local who is geared up to do this properly

thanks for the response

Rapid

Only thing to remember is that if your seatbelts mount to any part of the rollhoop then the IVA man will want to check the construction and that the arrangement is structurally sound. Otherwise there is no requirement for a rollbar under the IVA.

I am intending to mount the seatbelt points in the crossmember, but it will be a solid fixing

Arfon

Ash had issues at IVA with the rear diagonal only having one bolt in it as per the book.The IVA tester stated that becuase of the seatbelt mounts being part of the hoop this made it structural. I cannot remember his final solution but he either added a second bolt or welded it in. On mine I used a plate with two bolts in it to pickup the rear diagonals.

well we weld the base plates on so i cant see welding in pre formed bends is going to be an issue.
yes its not going to be as strong but it will only be as strong as its weakest point.
as for iva its the seat belts that the mans looking at if thay are fitted directly to the chassis then theres no issue

Where the rear diagonals go to the chassis my intention is to use two bolts with nylock nuts or castle nuts with split pins as we do in work, or another thought is to wire lock the nuts. Seatbelt mounts will be welded collars passing through the crossmount of the rollbar and fully welded top and bottom

Arfon

On the subject of roll bars does this appeal as a design?

Damit phil thats what I had in mind for my car you going to be knocking them out?

Looks like Desperate Dans Headboard:D

Thats well tidy Phil its nice to see different designs coming to the forum

Arfon

I have been playing with a few others ideas how ever the fish mouths/notches could be a pain to make.

Hi,
Phill is that a roll bar for the new VODOU chassis I see there:)
I made a very similar design to that a few months ago (wanted to be different I guess) Not to everybody's taste but I'm happy with it untill I think of something better.



Here it is drawn up on CAD





I'm not mounting my harness to my rear roll bar so need for rear stays which gives you plenty of room for designs.;)

Bye for now .....Johno

Love that one mate. Im still in the market for a rollbar so might have to get in touch. As im looking for one thats not too wide. I hate the boxy looking ones and would much prefer to go for a sleak one.

But would that be ok for the harness? as would think it might rub against the welds.

Hi,
Just been ebaying and found this...

http://www.ebay.co.uk/itm/Custom-mad...em4ab3d7 9cc8

Johno

good frind but 48mm seems a little on the small side

I've just ordered one so I'll update you all next week when it arrives

Rapid

Just found these on the bay, i like the look of them if they turn out alright might give them a go myself.

Roll bar arrived this week and must say I'm very pleased with it. It came with the mounting plates and the ends of the tubes have already been cut at the right angle ready for welding.

All in all good value for money in my eyes and I would recommend them - no fuss quick delivery and you get what it sayes on the tin

Rapid;)

how about one with two hart shapes :D

After this was made I came across a small problem in that you can not mount the seat belt top mounts to it, if you weld threaded bosses in to the tube you can't get the bolts in. The belts would have to go on the rear suspension cage and just lay over the bottom bar. This was made in 42x3mm it is not 100% matched side to side due to the home made bender we have and it is bloody heavy, how ever I think you would struggle to damage it much more than removing the paint in the event of putting the car shiny side down.
I'd ask these guys to bend it up for you.

http://www.ebay.co.uk/itm/Custom-mad...em4ab3d7 9cc8

Scorpion do fantastic work! They custom made my cage to my spec and did a fantastic job and did not cost a massive amount too! A***** service and quality. Think they use 49mm x 3mm wall