Advice Roll Bar hoop or FIA

[JNC]

I am not convinced ! Please help, My car is a 2012 SV with a standard hoop type but tube size 1,3/4" when I checked the FIA bar with cross the tube it's only 1, 1/2" and doesn't lean forwards as much as the standard bar . I know the FIA bolts from under the car as well but I can drill and tap mine for extra security. Surly CC wouldn't sell an inferior or unsafe bar ?.

[Julian H]

1.1/2" or 1.3/4" matters not, neither will protect you from the wildlife 

[Paul Richards]

I suspect the gauge of material is thicker on the FIA bar and also the triangulation provided by the cross on the FIA bar will greatly increase the strength.

Does the standard bar no longer have bolts from underneath? I'm sure it used to.

[JNC]

@ Paul, No the standard bar does not bolt from underneath only the top four on my 2012 car. I can see with the cross tube it makes it strong but does the larger tube counter that ?.

@ Julian, I was thinking with the extra cross bar I might catch the Pheasant instead of it going straight through ! LOL      Glad I have a windscreen an aero would not have been any good.

[Paul Richards]

No. Larger tube will have minimal effect compared to triangulation. 

[Comp Sec]

There is a great article coming out in the March issue of the Low Flying, which hopefullly will answer your questions.

with regards to drilling extra fixing holes, don't do any modifications to the trackday/FIA roll bar, if you ever want to use it for competition as you may have invalidated the Homologation certification. 

[JNC]

Hello Chris, the FIA bar is drilled and tapped so it can be bolted from underneath, The standard hoop on my car isn't only bolted from the top four fixings. My question is the standard bar is bigger and leans forward more than the FIA , Yes I know about geometry and strength of triangles but does this out weigh the larger new bar ?. When I said about drilling and tapping I was talking about the standard bar. Surly CC can't sell a substandard bar ? And is suitable for all uses ??.

[Comp Sec]

Have a read at the Low Flying when it lands.

Ford sell a Fiesta Van and a Ford Transit, does not made one substandard to the other, they are just designed to meet different requirements.

[Paul Richards]

CC can sell a car without any roll bar and they can sell you a car with a full cage. A full cage is "substandard" (inferior) to an FIA bar. Where do you draw the line?

If you do know about geometry and triangles then you'll understand that triangulation is much more effective than the diameter of material.

[Paul Richards]

Incidentally I've come across 3 factory built cars where the "underneath" bolts haven't been fitted. This was on imperial chassis with the thin head bolt which is easier to round, rather than the cap head bolt used on later cars. 

[Wrightpayne]

i have a special socket with the face ground flat for these bolts - the chamfer on the socket doesnt help so remove it. Pretty sure the disc / hub flange use the same thin head bolts.

Ian

 

 

[JNC]

Wouldn't it be better to use dome hex bolts ?

[Drumster]

On the imperial chassis dome headed bolts will be too thick and I doubt you'll be able to tighten them up sufficiently. I, too, have a ground down hex socket that works perfectly well. Done it many times as I swap between a cage for sprinting and FIA bar for road use.

[Ian B]

Paul is correct in that the triangulation of the cross bar will likely make the "FIA" bar stronger, but only of significance in an impact from the side where the force is against the triangulation. It is likely to have little effect when the forces are applied from the front or the rear.

The "standard" road bar as supplied by CC is deemed safe enough for use on the road and by many (all?) other trackday operators for use on their TDs. It is just that the Club historically introduced a rule to exclude them on TDs organised by the Club.

Neither bar is "FIA approved" on its own, as the "FIA" bar has only been tested with the Petty Strut fitted, so any claims that one or other bar are stronger when subjected to forces in a particular direction cannot be verified or quantified. One might be stronger than the other in a particular direction, but less so in another direction - there are no documented tests to prove or disprove this.

[JNC]

Thanks for your comments Ian, makes sense with petty strut , how often do the club  review the rules ? And take in owners opinion ! . Track use is fast but controlled  and all the cars go in one direction and in my opinion safer than road use !. 

 

[Slipper man]

One difference between the FIA bar and the standard is the materials used. The FIA bar is made from cold drawn seamless tube, whereas the standard is a welded pipe. The former is much stronger.