admin
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Roll Bars ??? do we don't we ????Right I have a question for the Experts on roll bars ....
If when the shocks are disconected from a car and roll bars are fitted what is the most common cause for the rear arms to lift unevenly
Example
if the rear right arm is lifted the left arm after a delay then lifts also
BUT
if the rear left arm is lifted the right arm does not follow as the other side did
:smt017 :smt017 :smt017
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admin
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Right now I have changed the Bar to a thicker one and now neither side lifts the other :smt017 :smt017
I changed the Bar to see if it had got bent or twisted So its not the actual bar thats the problem here :smt017 :smt017
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tom_reynolds
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It's probably the car Trev, I'd get another one... :smt019
I'n not sure how the roll bars attach on the cyclone, but if you disconnect the ends from the wishbones you need to check that the bar is free to move with no binding in its mountings on the bulkheads. It should be free to move in the usual twisting motion, but this will also enable it to move side to side, sliding through the mountings until constrained by the shape of the bar.
I suspect it is this that usually causes the uneven lifting, I have never managed to get this the same on any rallycross car (I've never really used them on a touring car). Try reconnecting the bar and pushing it to one side, then the other, and see if it makes any difference. I'd try it on my car, but it's still covered in mud from yesterday, and my spare car has no roll bars at the moment...
With a thicker roll bar and the shocks disconnected, if you lift up one side the other should respond quicker. If it doesn't there could be something binding involving the roll bar somewhere. It's not too thick for the mountings so they are clamping it down and not letting it rotate freely are they? I've had this a few times and have had to modify them to enable thicker roll bars to operate correctly.
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El Capitano
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Right then a couple of things to check out, I would check to see if the wishbones are free to fall under there own weight when lifted without the roll bar roll bar connected.
Second thing to check is if all the roll bar connecting rods and tie bars are the same length, next check to see if the roll bar is free to move in its mount. Now reconnect everthing to see if they work freely.
Remember that only the thick roll bars will lift the same either side,
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Juan Hu Nose
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Have to agree, most common cause is the brackets holding the bar are either tighented too tight against the bulkhead or the moulding needs shaving to let the bar move freely
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Juan Hu Nose
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Ot as Tom says, just get another car where they work :smt010 :smt010 :smt119
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Greyfox
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This question got me thinking, so I spent yesterday evening playing around with the various roll bars I have available for my MRE.
Having disconnected the shocks it was immediately apparent that the thin roll bars (1.25mm) I had on from Brooklands were just short of useless. Lift one wheel and the other stayed where it was! - no movement at all, so clearly it wasn't working. Looked a little closer and the plastic mounts for the roll bars have a slot cut into them to locate the bar, and this is too large for the bar as it moves up and down in the mount, negating the effect it should have on the opposite wheel.
Changed over to the thickest bar (1.75mm) I had and although there was slight movement in the mountings the opposite wheel moved in unison when the other was lifted. Then tried the 1.5mm yellow bar and that also had too much play in the mount to be of much use.
Conclusion
Call me an old cynic but I'm not convinced that different thickness rollbars make much difference. However I'm off to the LHS to buy some 2mm piano wire and make some bars up to see if these will affect the handling in any way - at least they won't move about in the mountings!
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admin
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So was you able to get some wire GreyFox to make your own roll bars ??????
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Greyfox
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No - but I'll have a look in the LHS in Cardiff this week and try to make them at the weekend.
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