julians Posted April 21, 2002 Share Posted April 21, 2002 Just been trying to fit an FIA roll bar, but I've stumbled across a problem. The build manual says the bar is secured from underneath (ie above the dampers) by 5/16" x 1" bolts. I've just been and bought some 5/16"x1" bolts but they are too small. I've tried some 3/8" bolts , but they are too big. Can anyone confirm the actual bolt type/size I should be using for this. TIA Julian Link to comment Share on other sites More sharing options...
sjwb Posted April 21, 2002 Share Posted April 21, 2002 M8 X 25 perchancequestion.gif Steve B Link to comment Share on other sites More sharing options...
felix.klauser Posted April 21, 2002 Share Posted April 21, 2002 I thought the one from underneath were 1/2 by 1" with the heads ground down to 1/8" high? Or is that for the full cage? Any which way, they'll almost surely be UNF, not metric. Link to comment Share on other sites More sharing options...
Gridgway Posted April 21, 2002 Share Posted April 21, 2002 not sure on size, but they have to be ground down to avoind fouling the shocks. Graham Link to comment Share on other sites More sharing options...
Top Hose Posted April 22, 2002 Share Posted April 22, 2002 The build manual says 5/16" x 1", but I seem to remember they were actually 3/8" x 7/8" when I fitted the FIA bar last year. Alan Link to comment Share on other sites More sharing options...
tony pashley Posted April 22, 2002 Share Posted April 22, 2002 3/8'' x 7/8'' sounds familiar. Could be they're the same as the shallow-headed set screws that were/are used to fix the rear discs to the hubs?? (Julian, when you say 'too big' - do you mean 'way too big' (wrong size) or just 'won't fit' (maybe a bit of powder coating needs clearing out with a tap?). Just a thought... Link to comment Share on other sites More sharing options...
julians Posted April 22, 2002 Author Share Posted April 22, 2002 I mean too big , definately wont go in. I've been on the phone to caterham this morning and they are sorting me out with some, they do need to have the head machined down to clear the top of the damper. Link to comment Share on other sites More sharing options...
V7 SLR Posted April 22, 2002 Share Posted April 22, 2002 Might I suggest that fitting them is a complete waste of time? Think about the loadings your rollover bar will encounter, should its services be required. The loadings will always be so as to negate the use of these bolts... and anyway, the big triangular plate has 3 bolts per side attaching the bar to the car. That's more than enough to be able to pick the car up with the rollover bar. Now, for the cage (which I just fitted yesterday), there is no triangular plate so the bolts you are describing seem more appropriate, although again, the loadings are always downwards (when the car's upright) onto the bar so maybe even this is overkill? Link to comment Share on other sites More sharing options...
julians Posted April 22, 2002 Author Share Posted April 22, 2002 But I presume the bar is no longer FIA approved if it isnt fitted correctly. Whether FIA approval actually means anything is a different matter altogether. Link to comment Share on other sites More sharing options...
felix.klauser Posted April 22, 2002 Share Posted April 22, 2002 The bolts were put there for a reason; it seems foolish not to bother fitting them if you're going to the trouble of fitting the FIA bar. Should the car ever roll and slide upside down, I would want every bolt in place to keep the bar in its place protecting by neck. Safety equipment is a pain in the a** until you need it and then it's too late to do anything about it. Link to comment Share on other sites More sharing options...
Fred Posted April 22, 2002 Share Posted April 22, 2002 your wheels will stay on with three studs need i say more question.gif fredid=blue> confused.gif Link to comment Share on other sites More sharing options...
felix.klauser Posted April 22, 2002 Share Posted April 22, 2002 So you run your car with three then? Try two; just think of how much more cenvenient it will be than 3 or 4. Link to comment Share on other sites More sharing options...
Fred Posted April 22, 2002 Share Posted April 22, 2002 totally agree put the bolts in fredid=blue> confused.gif Link to comment Share on other sites More sharing options...
V7 SLR Posted April 22, 2002 Share Posted April 22, 2002 Suit yourself... just thought it might save you a couple of hours of dismantling the rear suspension for a gain of "what" over the other 3 bolts per side holding it in place??? Link to comment Share on other sites More sharing options...
V7 SLR Posted April 22, 2002 Share Posted April 22, 2002 Oh, and comparisons with wheel nuts. Do you really think that bears comparison??? Link to comment Share on other sites More sharing options...
Fred Posted April 22, 2002 Share Posted April 22, 2002 the reason for the bolts holding the roll bar from underneath is to stop the bar from folding back or forward although you have the bolts on the plate at the top the bar is only secured by the welding on the plate so all that secures the bar is the welding not the bolts the bars at the rear act like a swivel when the bolts are left out under tests Oh, and comparisons with wheel nuts. Do you really think that bears comparison??? YES if your wheel comes of youl need that bolt you left out of the roll bar teeth.gif PS-- it only half hour job not two hours. fredid=blue> confused.gif Edited by - FRED on 22 Apr 2002 12:54:45 Link to comment Share on other sites More sharing options...
V7 SLR Posted April 22, 2002 Share Posted April 22, 2002 The roll hoop does not pass through the triangular plate and into the mounting hole. The roll hoop is of much greater diameter than the mounting hole and is in a slightly inward-location. There is another tube welded to the underside of the plate of the correct diameter and in the correct place to fall into the hole. It is for locating purposes only. The little bolt you all wish to install (which I'm not trying to stop - only trying to work out why it's there) does nothing except hold the locating tube in place. If you are worried that the hoop would fold at the weld-area of the plate, then I would suggest that the welding is crap and if that is so then the locating lug would similarly fail and pull off. If the bolt was that important, don't you think they may have designed it to be of slightly bigger dimensions (they deliberately offer a thin-headed bolt for this and advise against the use of a washer to spread the load because there's not enough room) and don't you think that the chassis member you bolt through would be of more substantial fare? Have you seen it? There's not much in the way of thickness of steel there. But again, look at the rear diagonals, their mounting points on the chassis look insubstantial. I've just fitted a cage yesterday and wonder at the lack of substance that you bolt to. The cage/roll bar looks far more substantial that the chassis to which you are mounting it. The cage, which does mount directly into the mounting holes, does not have the triangular plate (which I like). If I'd have been less impatient when my friend powder coated it for me, I may have taken him up on his suggestion to add triangular plates. The ones on the FIA bar are of construction thickness. Those welds won't fail, and I wouldn't feel in any way as though you are adding anything by fitting those awkward bolts. Perhaps the only answer, and quite obviously this is one I subscribe to, is a multi-point cage. The mounting points at the front of the cage are substantial. They're the ones that you would bolt your petty strut to. Incidentally, the petty strut and FIA bar are no lighter than my full cage. Now that's odd. I wonder what quality of metalwork is at play on each of these devices and whether anyone has ever done any actual testing when designing, or did they just over-design the FIA bar? Link to comment Share on other sites More sharing options...
Fred Posted April 22, 2002 Share Posted April 22, 2002 thumbsup.gif fredid=blue> confused.gif Link to comment Share on other sites More sharing options...
debushau Posted April 22, 2002 Share Posted April 22, 2002 When I fitted the FIA cage to my car - I asked the Caterham dealer whether I needed to put in these bolts - he replied that they were not needed (even though it clearly says otherwise in the manual). He may well have been motivated by the fact that I had been supplied the wrong roll bar and was not in the mood to wait 6 weeks for a new one before fitting the rear suspension. Link to comment Share on other sites More sharing options...
John Vine Posted April 28, 2002 Share Posted April 28, 2002 When my FIA bar kit arrived from Caterham back in May last year, the special vertical bolts were missing. When I queried this with the factory, they said that the bolts were deliberately not included, as most people didn't fit them anyway. But they sent them to me FOC (the Caterham P/N is 79085FIA). They are 3/8" with a special "flat" head. JV Link to comment Share on other sites More sharing options...
Gridgway Posted May 4, 2002 Share Posted May 4, 2002 when I asked Jez about it, the bolts are key to the bar installation being able to bear the forces required by the 'FIA spec'. Looking at them, it's hard to see that they add that much to the installation, but as they are trivial to fit, it's a no brainer. Link to comment Share on other sites More sharing options...
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