Re: [DML] Rob Grady's Personal Lower Suspension
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Re: [DML] Rob Grady's Personal Lower Suspension



Bill, making a true wishbone does not imply that the all the deflection would be from the ARB to the frame: there are other ways of connectin an ARB to the lower arms, making it to work indipendent of the arms travel, and the solution is to use a double link of uniball from the ARB to the arm, like this esample of arb: http://www.blackout.nu/BLACKBILDER/Rearend/AntiRollBar/UniballTest600b.jpg
like on lot of modern and studied cars.
How it works ? Simple, the up and down is directly trasferred, so the ARB works, but the foreaft movement is not, cause the 2 uniball links permits a lateral translation...
If someone want to make a true lower wishbone, wich is quite easy in the end, he has surely thinked about making a new ARB connection too ;)
I have also an idea for a bolton kit for a true lower wishbon wich connect to the frame without making any holes or weldings, and a new ARB with link...i'll let you informed.
Andrea #01748, Italy

----- Original Message ----- 
  From: content22207 
  To: dmcnews@xxxxxxxxxxxxxxx 
  Sent: Tuesday, November 08, 2011 8:55 PM
  Subject: Re: [DML] Rob Grady's Personal Lower Suspension


    
  Methinks you are arguing out both sides of your mouth:
  1) You claim that pseudo wishbones deflect too much (I guess that is why you are experimenting with true wishbones)
  2) You claim that eliminating deflection (ie: wishbones) is going to damage the frame

  Rob's LCA's are true wishbones (albeit with an odd tail hanging off for the ball joint and sway bar), with extremely little deflection, yet his frame seems just fine after decades of use. Should I expect anything less from my pseudo wishbones?

  Speaking of which: my pseudo wishbones *ARE* bushed at both the pivot and the shock mount ("middle"). Personally I think the sway bar yields before they do, but without a video camera mounted to my frame to record them in action we will never know for certain. Whichever is yielding out of sight, the feel from the driver's seat is stunning.

  Bill Robertson
  #5939

  --- In dmcnews@xxxxxxxxxxxxxxx, "Martin Gutkowski" <martin@...> wrote:
  >
  > Bending the arb or even twisting it are different forces to compression and tension along its axis, which even with the small "kink" would require massive forces to cause deflection. 
  > 
  > Before banging on about the arb's flexibility even more, please put one in a press and see what force it takes to deflect one of the "legs" along its axis. Because without compliant bushes, that's the force being put through the chassis every time the suspension moves.
  > 
  > Martin
  > 
  > Sent from my BlackBerry®
  > 
  > -----Original Message-----
  > From: "content22207" <brobertson@...>
  > Sender: dmcnews@xxxxxxxxxxxxxxx
  > Date: Tue, 08 Nov 2011 18:41:57 
  > To: <dmcnews@xxxxxxxxxxxxxxx>
  > Reply-To: dmcnews@xxxxxxxxxxxxxxx
  > Subject: Re: [DML] Rob Grady's Personal Lower Suspension
  > 
  > I never said that the sway bar ripping itself off was a personal attack -- I said it was a Red Herring.
  > 
  > To accommodate my sway bar I turned the bushings around, so it presses into an empty space:
  > http://a7.sphotos.ak.fbcdn.net/hphotos-ak-ash4/s720x720/375011_267060150005909_100001057778755_815811_2047237322_n.jpg
  > 
  > Combined with the sway bar's inherent flexibility (*THAT'S* my beef -- arguments that the sway bar is adequate to hold the LCA's still), there is no problem with its range of motion.
  > 
  > Bill Robertson
  > #5939
  > 
  > 
  > --- In dmcnews@xxxxxxxxxxxxxxx, Marc Levy <malevy_nj@> wrote:
  > >
  > > Bill,
  > > 
  > > You seem to take this all so personally. I am not sure why?
  > > 
  > > Ever since I first saw Rob's setup, doing this to my own car has been something I thought about. To find out that the arms were done by Mike Loasby does give it some credibility, and having more people install similar systems (like Ed's kit) adds more data to the mix. At one point I even suggested that Rob try and reproduce this part in larger quantities (at the time, Ken was making new LCA's to order). 
  > > 
  > > There are other things going on in the system that are of concern to me (and others). Publicly stating those concerns is NOT an attack on you. In this discussion, the arc of travel for the ARB is real, Mike Loasby commented on this (old DMCTalk site), and expressed concern about it. It is very possible that even with Rob's "wishbone" LCA's there is still enough movement in the system to accommodate it, that does not mean the issue should be ignored! There is an INCREASED possibility of damaging the ARB mounts on the crumple tubes when the LCA movement is restricted. Do you deny that? I hope it never happens, but it is a legitimate concern that has only been addressed by saying "I don't have this problem", and the backup is "Rob does not have this problem either". That may be enough for some others to have the courage to give it a try, but to encourage the masses to do it is irresponsible. 
  > > 
  > > The fact remains that building a custom LCA like this is not something most owners will want to risk doing. It is a significant modification (much like installing a carburetor or a Nissan VQ35), and I don't think it is a good idea to advocate it as a modification "ready for the masses". 
  > > 
  > > I am glad you did this to your car, it adds another data point for those of us still pondering the idea. Hopefully you will continue to report your results (GOOD AND BAD) for the rest of us. Clearly you are happy with it so far, so I am happy for you. If at some point I do decide to modify my car this way, I will be sure to report my results too- But I doubt I will be proselytizing that everyone else do it too. I have already made a few calls looking for spare LCA's to modify. 
  > > 
  > > 
  > > --- On Tue, 11/8/11, content22207 <brobertson@> wrote:
  > >
  > 
  > 
  > 
  > 
  > ------------------------------------
  > 
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