Very rough ride

[Hipster]

another double post.

 

[Hipster]

Lol

Well that was what he was wanting to do.

 

[Hipster]

That's not what progressive means..... it's the rate, not the stiffness. A linear spring gets stiffer at a constant rate, meaning it's adding more resistance to compression in the same amount...... 1+1+1+1. Progressive would be more like 1+1.5+2+2.5.... it's getting stiffer faster.

If they weaken, and we add preload, we're restoring the stock ride height and tension, and if a linear rate, more twist (when the suspension cycles) will add the same amount of tension per degree of twist. I am not a spring expert, but I don't see how that would make a rougher ride.

My dad made a few knives when he was young and worked in a machine shop. I think he usually used industrial power hacksaw blades. I can't imagine trying to pound a torsion bar flat by hand.

All springs increase in rate as they go through the motions, whether it be coils or torsion springs. Like a valve spring which is not progressive might exhibit 100lbs static on the seat and a half inch later it's at 280lbs. Shimming .030 will bring the seat up to 115 and open close to 300.

On a vehicle cranking like you said puts the starting point at a little more twist/pre-load so you are starting higher up the springs scale and you also have a control arm that acts as leverage with the downward force the ball joint sees. A torsion bar with a static load rate at ride height of 250 lbs might be at 375 under full compression. Crank it and depending on how much you might be starting at 275 and end up at 425. These are just general numbers. I know the T-bars in my Mopar go from something like 225 at ride height to 350 at full compression.

Also, if you control arm is parallel to the ground at say a 90* angle that is what would be a neutral position. Crank it up 2 inches and change that angle to 60* you change the way the suspension reacts.

At a 1/2 inch or 3/4 from stock you may never notice the difference but at the extreme of 2 inches plus you change quite a few dynamics of how the suspension is working.

 

[magimerlin]

1997 k1500 5.7. When driving on Norma flat roads my ride is still rough and bumpy. My keys are cranked a little but just enough to level the truck and I changed all the front suspension except cv axles and hubs. What could be causing all this vibration and rough riding. I’ve also got new rims and tires and it still does this

Did you get an alignment after you changed everything?

Sent from my SAMSUNG-SM-G891A using Tapatalk

 

[454cid]

All springs increase in rate as they go through the motions, whether it be coils or torsion springs. Like a valve spring which is not progressive might exhibit 100lbs static on the seat and a half inch later it's at 280lbs. Shimming .030 will bring the seat up to 115 and open close to 300.

On a vehicle cranking like you said puts the starting point at a little more twist/pre-load so you are starting higher up the springs scale and you also have a control arm that acts as leverage with the downward force the ball joint sees. A torsion bar with a static load rate at ride height of 250 lbs might be at 375 under full compression. Crank it and depending on how much you might be starting at 275 and end up at 425. These are just general numbers. I know the T-bars in my Mopar go from something like 225 at ride height to 350 at full compression.

What you're describing isn't rate, but the total. If the bars are cranked to maintain original ride height (assuming no more weight has been added to the vehicle) there is no more pressure on it than stock.... otherwise it would ride higher.

 

[Hipster]

What you're describing isn't rate, but the total. If the bars are cranked to maintain original ride height (assuming no more weight has been added to the vehicle) there is no more pressure on it than stock.... otherwise it would ride higher.

Correct, and it would sit at the same height but they sag because the spring rate is disappearing, restoring the ride height doesn't bring back the spring rate on a whooped spring. The same total psi might or might not be there or it might be past the fracture point. By doing such at full compression you're twisting it further then was ever intended. I've never heard too much about the T-bars in out trucks maybe because of the sheer size, but if you keep cranking 50 y/o T-bars in a muscle car to maintain ride height eventually you get to the failure point and even once you get it back to the correct ride height it will still wallow down the highway because the total is not there either.

If you have to keep adjusting ride height the spring is at the end of it's life and they can fail.

 

[454cid]

Correct, and it would sit at the same height but they sag because the spring rate is disappearing, restoring the ride height doesn't bring back the spring rate on a whooped spring. The same total psi might or might not be there or it might be past the fracture point. By doing such at full compression you're twisting it further then was ever intended. I've never heard too much about the T-bars in out trucks maybe because of the sheer size, but if you keep cranking 50 y/o T-bars in a muscle car to maintain ride height eventually you get to the failure point and even once you get it back to the correct ride height it will still wallow down the highway because the total is not there either.

If you have to keep adjusting ride height the spring is at the end of it's life and they can fail.

I agree with the above, but the OP's complaint is a rough ride, not wallowing. Wallowing would me more like too soft, in my mind.... unless maybe he's fully extending and compressing due to weak t-bars? I didn't get that idea, since he mentions flat roads, but you did mention him wanting to cut off bump stops awhile back so who knows

 

[_nickjoseph]

I agree with the above, but the OP's complaint is a rough ride, not wallowing. Wallowing would me more like too soft, in my mind.... unless maybe he's fully extending and compressing due to weak t-bars? I didn't get that idea, since he mentions flat roads, but you did mention him wanting to cut off bump stops awhile back so who knows

I only wanted to cut them so that I wouldn’t have to deal with them
Hitting but decided not to because I’ll be getting a lift pretty soon. I just was wondering why it was so rough even with them not fully cranked. I have the z71 package and just checked my shocks, they’re not the ones for the z71, they’re just for 4x4. Would this impact it?

 

[Hipster]

I agree with the above, but the OP's complaint is a rough ride, not wallowing. Wallowing would me more like too soft, in my mind.... unless maybe he's fully extending and compressing due to weak t-bars? I didn't get that idea, since he mentions flat roads, but you did mention him wanting to cut off bump stops awhile back so who knows

We kind of went off track there. He hasn't responded when asked if he had lowered it since he asked about the bump stops. Ihmo he still has it cranked up quite a bit.

 

[Hipster]

I only wanted to cut them so that I wouldn’t have to deal with them
Hitting but decided not to because I’ll be getting a lift pretty soon. I just was wondering why it was so rough even with them not fully cranked. I have the z71 package and just checked my shocks, they’re not the ones for the z71, they’re just for 4x4. Would this impact it?

Z71's came with Bilsteins but a different shock is not going to do anything for you with the increased pre-load limited travel situation cranking creates. With little to no compression or extension there isn't anything for the shock to control. It's all been discussed within this thread. If you're looking at lift kits look past the control arm/diff drop kits into something more along the lines of an RCX or similar that moves everything down if you're looking for a decent ride.