Big sway bars.

Discussion in 'The whoa and the sway.' started by BrianinStLouis, Jun 23, 2018.

  1. BrianinStLouis

    BrianinStLouis Silver Level contributor

    Do you guys think large sway bars adversely affect the ride quality?
    The BBB 72 Suncoupe kind of drives like a tank.
    I have replaced all of the front end components, all the way down to the springs. Also had 2 front end alignments. The last shop that performed the front end alignment is a suspension specialist. (Not NTB)
    He runs an old school shop and claims everything, front and rear, is spot on.
    The car just drives like crap. One of the symptoms is when I hit a bump, the rear of the car actually feels like it bounces slightly sideways.
    I thought I'd ask here before I remove the sway bars to test.
    Any ideas?
  2. telriv

    telriv Well-Known Member

    Smartin likes this.
  3. BrianinStLouis

    BrianinStLouis Silver Level contributor

    4 new shocks made no difference.
  4. Bluzilla

    Bluzilla a.k.a. "THE DOCTOR"

    What's the load rating of your tires? The higher the load rating, .... the stiffer the sidewall, .... the rougher the ride. You may want to experiment by adjusting tire pressure within safe limits. A Very Large Diameter rear sway bar can cause the rear sideways movement over sharp bumps because both rear tires will try to lift equally when one tire hits a bump. Though front end sideways movement may be attributed to excessive "bump steer".

    Last edited: Jun 24, 2018
  5. Golden Oldie 65

    Golden Oldie 65 Well-Known Member

    I had big sway bars on mine (1 1/2") but I run smaller tires in the front and whenever I got heavy into a curve the front tires wanted to slide. I mentioned it here on the board and someone suggested that because of the heavy front bars that I wasn't getting the weight transfer onto the front tires. They were right. I put the smaller bars back on (1" front and 7/8" rear) and the car handles the curves much better. I can't really remember if the bigger bars made the car ride worse but I did learn that in my case they weren't doing me any good. Other than Hotchkis springs and KYB Gas-A-Just shocks, my suspension is otherwise stock with rubber bushings.
    Demoman and Harlockssx like this.
  6. knucklebusted

    knucklebusted Well-Known Member

    Sway bars, unless excessively huge, should have very little impact on ride quality on non-curved driving. They serve the purpose to link the sides of the car together to reduce body roll.

    You can try an experiment. Put a jack under the frame behind the front wheel and jack the car up. See how high you have to go before the other side lifts, if it will. Measure the height of the jacked tire. Repeat with the sway bar end disconnected on one side. How much difference was there?

    Repeat with the rear under one the rear frame just in front of the rear wheel. Is there a big difference?

    Also, note that this is the amount of body roll you can get in a static situation.

    As to your problem and the symptoms described. Have you confirmed all the bushings in the rear are good? It sounds like it could be slop in old bushings. That's what I'd check next if you rule out sway bars but then again sway bars may just be forcing more load on a poor bushing, amplifying the issue.
    Harlockssx likes this.
  7. BrianinStLouis

    BrianinStLouis Silver Level contributor

    Thanks Folks,
    The tires are BFG radials. Probably pretty old too, but visibly, they look fine. They were on the car when I bought it from Staged70.
    The car had been stored for years with minimal driving.
    I'll have to double check the rear suspension. Also, the Edelbrock shocks I put on were new, but had been on the shelf for years.
    My SB 71 Skylark had KYB shocks and rode like a dream, no rear sway bar and the factory front sway bar.
    We've just bought a newer home, and if all the inspections go well Monday, I'm gonna be pretty busy. Plus the St. Louis summer is scheduled to hit like a BFH in a few days.
    But.... if we move into the new home, I'll finally be able to keep the Suncoupe at the same address as me- much easier to get garage time.
    Thanks again.
  8. 12lives

    12lives Engage! - Jean-Luc Picard

    Congrats on the new home! Good luck with the purchase!

    What size are the sway bars? Are the front sway bar bushings the kind you can lube?
  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    I am going to say tires. I had the BFG's before and I found they rode hard. I have The Cooper Cobras now. They ride much better, and I have more air in them to boot (37 psi)
    Mark Demko likes this.
  10. BrianinStLouis

    BrianinStLouis Silver Level contributor

    The front sway bar is larger in diameter than what was on the front of my 71 Skylark . I must confess, I do not know the size. I suppose I could remove the sway bar bushings and apply some white lithium grease.
    The tires are 60 series. I thought BFG's were the go to tire, Although, I had Coopers on my 71 and it rode great.
    ..and thanks for the well wishes Bill.
  11. knucklebusted

    knucklebusted Well-Known Member

    Any chance you could swap tires between the two vehicles to see if the problem stays with the car or with the tires? Tires are my second thought if the bushings are good in the rear.

    I had a situation when going around corner where it felt like something heavy was shifting in the trunk of my car. Trunk was empty. Turned out to be worn bushings in the lower control arms and a slotted upper control arm at the rear end.
  12. Smartin

    Smartin Staff Member

    I had a set of tires do that...went through the entire suspension and a set of new shocks. Finally replaced the tires due to age, and the problem magically went away.
  13. BrianinStLouis

    BrianinStLouis Silver Level contributor

    I may be able to borrow a set.
  14. 12lives

    12lives Engage! - Jean-Luc Picard

    As long as the bars are not excessive in size, I can't imagine them affecting the ride. As said above, likely tires or shocks if the suspension checks out OK. I run big bars (1" rear/1 1/4" front(stock trans am)) and 15" TA Radials in a 67 wagon and the ride is good.
  15. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    On one wheel bumps, the bar adds to the spring rate on that side, so yes, it can affect the ride. I have a 1 3/8" front bar, and the HR Parts n Stuff rear bar. The car rides very nice. I saw a big improvement with these Cooper tires as mentioned. They are 44 psi max tire and I run them at 37 psi.
  16. Bigpig455

    Bigpig455 Fastest of the slow....

    Just switched to Coopers from General XP2000's (branded as Hooseier GT's) and not only did the ride improve, but lost most of what I used to think was bump steer....
    Harlockssx likes this.
  17. 12lives

    12lives Engage! - Jean-Luc Picard

    I just noticed you said the BFGs are old. In my experience, old (~8+) tires tend to get hard, even radials. I'd be looking for new tires!
  18. BrianinStLouis

    BrianinStLouis Silver Level contributor

    I'll need to find out about the date code on the tires.
  19. BrianinStLouis

    BrianinStLouis Silver Level contributor

    On a side note, then new home deal didn't happen.
    The HVAC system was original to the house at 26 old. The Seller was willing to drop the price a whole 2K.
    It was mutual agreement to kill that deal.
    I'm OK with it, I was going to have to have another garage built anyway.
    Now, once the 1000 degree temps drop, I'll check on some tires. I was looking in on the car the other day and noticed the rears are getting a little thin....they may be due for a smokey death.
  20. black70buick

    black70buick Well-Known Member

    Add sway bars, some ride softness will be taken away but handling will be superb! You can hang with most modern cars. I can not over state this. I just got back from a never before, unintended drive through the mountains - why this happened is a different story. Years ago, pre front sway bar upgrade and addition of rear swaybar, my white knuckle factor would have been high - all else being the same. Same white wall tires, same springs, same shocks. Now, I did recently add some "drag bags" to the rear but they have not made any noticeable difference except to prevent the rear from sagging when 5 people and a trunk full of stuff are being transported. I was so extremely happy with the car, I took videos of this big classic with white wall tires road hugging in the mountain where tight turns and switch backs are numerous. It was fun.

    Buy front and rear sway bars and don't give it another thought. Seriously.

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