Roll bar or chassis brace?

Wheels, Suspension, Brakes & Tyres questions and answers

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zephyrus17
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Re: Roll bar or chassis brace?

Postby zephyrus17 » Tue Nov 20, 2012 5:45 pm

plohl wrote:Have you got an references for this 1% improvement? I would love to have a read of how they tested it. Was through testing or simulation/calculations? Or is it just speculation/a guess?

Hahaha cool down. I don't have references, and I doubt anyone does. I'm just saying that if he wants chassis stiffness, getting a roll bar is the wrong way to go. There might be a stiffening effect, as negligible as it might be, but it's just the 'long way round'.
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sailaholic
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Re: Roll bar or chassis brace?

Postby sailaholic » Tue Nov 20, 2012 5:59 pm

I think the point was you don't actually have any data to make that claim any better than the people who "feel" a difference.

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plohl
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Re: Roll bar or chassis brace?

Postby plohl » Tue Nov 20, 2012 11:19 pm

zephyrus17 wrote:
plohl wrote:Have you got an references for this 1% improvement? I would love to have a read of how they tested it. Was through testing or simulation/calculations? Or is it just speculation/a guess?

Hahaha cool down. I don't have references, and I doubt anyone does. I'm just saying that if he wants chassis stiffness, getting a roll bar is the wrong way to go. There might be a stiffening effect, as negligible as it might be, but it's just the 'long way round'.


I assure you, i am cool 8)
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plohl

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KevGoat
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Re: Roll bar or chassis brace?

Postby KevGoat » Tue Nov 20, 2012 11:24 pm

OK, first off I am by no means knowledgable on this subject. Seat of the pants only lol.

I don't really agree with fitting a roll bar to improve handling or stiffen the chassis. Not even sure they do for that matter, though I do feel mine did, but maybe I just wanted to after $$$ spent. Sure, by fitting a roll bar - for protection - and gaining some benefit, that's a bonus, but any handling problem has to be sorted by looking at ALL the the suspension and chassis.

I agree with HJT on this one, there is another issue here that needs fixing, otherwise fitting a roll bar may just mask the problem - possibly dangerously so! Maybe the shocks/springs aren't matched well enough, maybe there are worn bushes as mentioned or maybe there are other mods that have upset the handling. But I would have thought it was more important to sort this problem out first before thinking about fitting a roll bar as a fix.

In my case, fitting the roll bar (BD) actually created handling problems, not sorted them! My car felt pretty good until I fitted the bar, then I suddenly had this vibrating bounce after some road bumps. I reduced the tyre pressures lower than I had previously. This partially sorted the problem. I then fitted a front lower brace, which has reduced the vibration even more, but it is still not completely sorted. I reckon the roll bar has shown up that my shocks (Monroe Sensa-Trac) were never really up to handling the stiffer King springs. Its not that bad so I can live with it for now, but this to me shows it's the basics that really count.

sweep77
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Re: Roll bar or chassis brace?

Postby sweep77 » Wed Nov 21, 2012 6:41 am

As far as I'm aware my car is all standard. Lowering the tyre pressures has helped so I might just take it to mx5 factory and get them to check it. Shocks feel firm but not sure if they are original Mazda. They look factory black.

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lightyear
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Re: Roll bar or chassis brace?

Postby lightyear » Wed Nov 21, 2012 9:27 am

The only thing that I have used to stop scuttle shake was a hardtop. Most believe the hardtop does nothing. But it stiffens the car diagonally. Something the softop can not do. I even used one of my c.f hardtops with only the front and rear bolted down, and it stopped scuttle shake.
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Tony
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Re: Roll bar or chassis brace?

Postby Tony » Wed Nov 21, 2012 10:21 am

lightyear wrote:The only thing that I have used to stop scuttle shake was a hardtop. Most believe the hardtop does nothing. But it stiffens the car diagonally. Something the softop can not do.


I agree with Dave, that's been my experience as well.
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KevGoat
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Re: Roll bar or chassis brace?

Postby KevGoat » Wed Nov 21, 2012 10:23 am

Could also try my trick where I spent ages just checking every nut/bolt I could find. Would not believe how many loose nuts/bolts I found and how many were missing!! That task alone tightened my car quite a bit :lol:


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