Roll cage repair opinion

[Kinkell]

Racing incident caused a 70 mm bend on the roll cage at the drivers A pillar on my old Escort mk1. It's a simple push out repair to get it back to where it was but my friendly repair guy is reluctant and worries that the cage is now compromised and should be replaced. It's a period bolt in cage not a modern steel item and our local scrutineer has said that It would be fine if straightened. It's got to be a common situation so anyone been in the same position?

[tapkaJohnD]

I'm amazed that a scrutineer should tell you that.

If the cage is bent it has done it's job and can be sent to the Great Garage in the Sky with honour!
Apart from the fact that it has 'failed' in the metallugical sense, reached beyond its yield point on stress, while not failing and ?saving your life?, there can be an enormous amount of energy still trapped in it. As you start to cut it out, beware of parts springing into unexpected positions.

Sorry, but you need a new one.
John

[Kinkell]

Thanks for your opinion but there will be no cutting out just a bend back into original position. These cages are bent into shape and according to racing folk can be bent back without weakening the structure. I am rebuilding the shell with new panels and would replace the cage with a welded in job if persuaded.

[tapkaJohnD]

Don't know which "racing folk" you know.
None of mine.
JOhn

[stevieturbo]

Kinkell said:

Thanks for your opinion but there will be no cutting out just a bend back into original position. These cages are bent into shape and according to racing folk can be bent back without weakening the structure. I am rebuilding the shell with new panels and would replace the cage with a welded in job if persuaded.

Seems fairly reasonable. Nobody seems to be complaining about all those bends in the cage to make it fit a car !

Exactly what was bent, and more importantly how did it get bent that other aspects were not damaged ?

[Kinkell]

Hit on the A pillar with the front leg of the cage moving 70 mm into the cabin, door bar, floor, roof undamaged. I may fit a dash bar to increase lateral strength.

[HustleRussell]

I'd be apprehensive about straightening a bent tube, particularly one of those which is keeping the roof above your head. It's not a practice I have come across. There is no way that the tube will be just as strong when straightened as it was before it was bent. Once bent and straightened it has been weakened and will be much more prone to buckling again, to a greater degree than it did before.

If the cross section of the tube is in any way crushed, dented, gone oval etc It is an especially bad idea.

[TimCrighton]

New cage time if it was me. If the floor had moved and it had tweaked the location of a leg but not actually bent a tube so it released on undoing it that is one thing, but a bent bar in a cage I think I'd be wanting to replace it.

[Kinkell]

New front cage on order from West Wales, thanks for the replies.

[tapkaJohnD]

Well done, Kinkell! Good sense!
JOhn

[Kinkell]

Minimal expense in the vast fkwittery expenditure involved in motor racing at club level for workin folks.