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Anti Roll Bar Supply Problems 
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Post Anti Roll Bar Supply Problems
I phoned Jim Walker yesterday to try and order a set of anti roll bars. The last batch of steel he got was no good and failed tests with it breaking. He's been waiting 3 months so far for some steel to be available and isn't confident of any arriving as it's a rather old spec.

With that in mind is anyone:
1. In the Essex/South East area and happy for me to come and measure up the bars? I'd need to disconnect the drop links and load them up to get a measurement to give me the shear modulus.
2. Interested in an anti roll bar kit so that I can try and negotiate a group build if I can find someone else to manufacture them with an alternative steel spec that will match.

If there's enough interest for a group buy I'd be considering costing both a copy of both bars and also a straight front bar with splines and blades so it's easy to fit and change.

Phil


Tue May 23, 2017 7:31 pm
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Post Re: Anti Roll Bar Supply Problems
I'd be very interested in that Phil. I've been speaking to Jim Walker for the best part of a year regarding roll bars so it looks like we may need to go down another route.

No disrespect to Jim, who's a top man, but he has other priorities.


Tue May 23, 2017 8:51 pm
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Post Re: Anti Roll Bar Supply Problems
I'm following a different route. I'm hoping to get a torsion bar/lever arm set up made by Dave Gallop at Track Developments. As he's local to me (based in Sherston, near to Castle Combe circuit) and he's in my local kit car club it seems an obvious choice. The other main advantage of this way of doing it is the torsion tube can be passed through the holes above the steering rack and the lever arm fixed after so need need to dismantle the front of the car. He's given me a measurement sheet for me to take a load of dims, including throughout the whole range of movement of the wishbones. He can calculate the roll centre and work out the optimum stiffness. He has done bespoke ARB's for many kits and race cars and definitely knows his stuff (was a race engineer for most of his working life). He also redesigned the Westfield pushrod ARB that a few guys I know have got as it was cracking their chassis!

Once mine has been sorted there is no reason why he can't make more and he was talking different rates for design/supply or for him to fix it too but after having a look at mine at our last pub meet I think he'll prefer for me to fit it myself as he didn't fancy the access hole to get to the back of the fixing points!


Tue May 23, 2017 10:06 pm
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Post Re: Anti Roll Bar Supply Problems
Oh yeah, if anyone saw his stand at Stoneleigh (shared with Protech shocks) he had some mock ups of the torsion tube/lever arm arrangement principle


Tue May 23, 2017 10:08 pm
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Post Re: Anti Roll Bar Supply Problems
That's awesome, my comment on "straight front bar with splines and blades" is the same as your torsion tube/lever arm. Count me in. Is this just a front end solution? If so, is there a rear end option?

And I agree the access to the mounting points sucks, big time.


Tue May 23, 2017 10:16 pm
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Post Re: Anti Roll Bar Supply Problems
Dave G certainly knows his stuff so if he can make one that would be a cracking option - be very interested in him making me one too. Going to get him to set my car up eventually as well.
How far have you got with this? If it a ball ache for you to get the measurements I'd be happy to do the honours when I've got my front clam off in a couple of weeks (when it comes back from its z cars holiday)?

Have you asked him about a rear bar as well?


Tue May 23, 2017 10:20 pm
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Post Re: Anti Roll Bar Supply Problems
I've not taken any dims yet - not in a mad rush and Dave is quite busy too but if anyone else has more time/better access to their wishbones etc I'd be happy to share the dim sheet Dave's sent me. I'm not sure there would be any economy of scale in a group buy as its a small scale set-up anyway, although he gets the lever arms laser cut elsewhere so there may be some benefit in getting several of those done in one go and once the sums are done they are done for all of us. Rather than splined connections he was talking about a hex cut out in the lever arm welded to a section of hex bar and that would be an interference fit/plug welded inside the ends of the torsion tube. I'll pass on to Dave that there might be others interested.

In terms of rears, he tells me the rear doesn't do much and that often rears are made far too hard and that will do more harm than good but a soft rear can be used to fine tune the balance of the car once the front is set right. Once the front is cock-on a small adjustment on the rear can tune it form understeer to oversteer and allow the driver to steer on the throttle which is just what I'm after.


Wed May 24, 2017 9:19 pm
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Post Re: Anti Roll Bar Supply Problems
Interesting stuff. I know that most people were running their rear bars pretty soft to avoid snap oversteer so that aligns with what Dave's saying. A few people ran with front only or the rear bar disconnected and said it made no difference.

Regarding the dims sheet, I'd appreciate if you could send me a copy as the front end of my car will be dismantled fairly soon is it'll be easy for me to take the measurements and save you the hassle of trying to do it around all the various parts.


Wed May 24, 2017 10:03 pm
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Post Re: Anti Roll Bar Supply Problems
My experience was I went from fully soft on the rear ARB to one hole off fully hard once I had the Z Cars suspension. So I would say they are worth having.


Wed May 24, 2017 10:26 pm
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Post Re: Anti Roll Bar Supply Problems
PhilTheGeek wrote:
......
1. In the Essex/South East area and happy for me to come and measure up the bars? I'd need to disconnect the drop links and load them up to get a measurement to give me the shear modulus.
........


77 Gpa is the norm for steel. It hardly changes. The more critical one is the steels resistance to yield as that is when the bar goes past its elastic limit.

Neil

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Wed May 24, 2017 10:37 pm
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Post Re: Anti Roll Bar Supply Problems
I'd be very interested in this Phil and also i am in the Essex/South East area. i have the z car stuff on its way to me and it seems a bit silly not to have anti roll bars. i can not help but think there is a off the shelf solution that can be made to work some where but i think this may just be wishful thinking.


Thu May 25, 2017 1:13 pm
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Post Re: Anti Roll Bar Supply Problems
After reading comments on here about rear anti-roll bars, thought I'd try changing some settings (again!).
I thought mine was set to the hardest, but now i'm not sure. Can someone confirm if mine is set to hardest or softest from this pic.
Cheers


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Mon May 29, 2017 11:24 am
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Post Re: Anti Roll Bar Supply Problems
That's set to full soft as it is.


Mon May 29, 2017 12:05 pm
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Post Re: Anti Roll Bar Supply Problems
That's the softest setting.


Mon May 29, 2017 12:06 pm
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Post Re: Anti Roll Bar Supply Problems
Thank you.
I had tried it in the hole at the other end but it felt worse. I'll leave it where it is for now.

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Mon May 29, 2017 12:29 pm
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