Best way to make a roll cage stronger? - Saxperience

-shuggles- · 18th February 2011, 18:56

Hey guys, I was just wondering where you all reckon I should add more bars in too my roll cage as I am doing it in the next couple of days. At some point in the near future the car will be getting poly bushed,bilstien dampers, semi slick trackday tyres ect as I want it to handle really well since it will be lacking in power so I might as well do the cage properly

any ideas?

Ryan^p · 18th February 2011, 19:00

wtf has someone done to the front section cut the legs off?? (bottom pic) huge gap between main hoop and leg.

There are a few things you can do but a badly modded cage can be more dangerous.

Many people go for X section on the rear with harness bars, you can add X door bars, then supports between the rear legs and main hoop, then theres a bar between the hoop legs low down, triangulation through the bulkhead to strut tops..

etc etc....

But remember this will add weight, and if you dont have power then fuck knows. Many of the basic designs like yours is now (appart from the cut off sections are still FIA approved

-shuggles- · 18th February 2011, 19:02

Quote:

Originally Posted by Ryan

wtf has someone done to the front section cut the legs off?? (bottom pic) huge gap between main hoop and leg.

There are a few things you can do but a badly modded cage can be more dangerous.

Many people go for X section on the rear with harness bars, you can add X door bars, then supports between the rear legs and main hoop, then theres a bar between the hoop legs low down, triangulation through the bulkhead to strut tops..

etc etc....

yeah my mate welded it into his old saxo and I guess he cut it to get it out of the car, I am going for an 'X' with harness bars and something else.

I am aware it could cause more danger and what it's worth but the person welding my cage is 1 of the best welders around my area

Ryan^p · 18th February 2011, 19:08

it still makes no sense to have cut the front legs. Theres a sleve joint there usually

-shuggles- · 18th February 2011, 19:31

Quote:

Originally Posted by Ryan

it still makes no sense to have cut the front legs. Theres a sleve joint there usually

yeah there was but I think he put the cage in and welded it all up under the impression it would stay there for good.

axsaxoman · 18th February 2011, 19:33

put in the scrap pile and gte a proper one

KamRacing · 18th February 2011, 19:34

As its not linking to the chassis in many places its not currently going to be offering much in the way of torsional stiffness. Have a look at images of racecars and copy some of their designs. It does look ropey though!

Ryan^p · 18th February 2011, 19:36

Quote:

Originally Posted by -shuggles-

yeah there was but I think he put the cage in and welded it all up under the impression it would stay there for good.

should have left it there or just cut it up into bits.

I personally wouldnt want 2 joins in the section that protected me, like that

axsaxoman · 18th February 2011, 19:43

your first pproblem is a home made cage will not be passed as fit for use in form of proper motorsport --cages must have certification plate on them
and any serious cage will be attached on screen pillars and above doors and down the post behind the doors and will be welded in on plates which spread the load over a much larger area than that of the foot on the cage leg .
first rule of fitting a cage is mount car on 4 axle stands making sure that they are all same hieght --or you will end up with a twisted shell .
check the doors open and close correctly when on the stands before attaching cage --if doors do not line up then you are not supporting the shell correctly.
also no cage will be a perfect fit without some adjustments ,

-shuggles- · 18th February 2011, 20:53

thanks for the advice despite it being bad news

blackie_2k5 · 19th February 2011, 00:42

the rear half and door bars are useable, the rest needs remaking, theres no point fitting it like that, the whole purpose of the legs is to shield impact from front/side/roll impact, joining it where its going to need to be.... is gonna create massive weak points at major load points, which will cause them to break imediatley regardless of how good a welder fitted them... once broken there in the cab where they could impale you..... you really would be very daft to try and repair that mate, could get new front legs made up fairly cheap, just dont use cheap metal

as ryan sais, id rather have no cage then a bad cage

-shuggles- · 19th February 2011, 12:29

Quote:

Originally Posted by blackie_2k5

the rear half and door bars are useable, the rest needs remaking, theres no point fitting it like that, the whole purpose of the legs is to shield impact from front/side/roll impact, joining it where its going to need to be.... is gonna create massive weak points at major load points, which will cause them to break imediatley regardless of how good a welder fitted them... once broken there in the cab where they could impale you..... you really would be very daft to try and repair that mate, could get new front legs made up fairly cheap, just dont use cheap metal

as ryan sais, id rather have no cage then a bad cage

I will get the from re-made asap.

thanks mate

solvi · 22nd February 2011, 13:37

take a look at www.vimesasport.com.

they have a very well done multipoint bolt-in cage and is FIA aproved for any kind of motorsport.
they send it worldwide.

solvi · 22nd February 2011, 14:38

http://i1229.photobucket.com/albums/...t/image001.jpg.

very very stiff...