Leaf springs and shocks

[updraught]

https://www.jstor.org/stable/44716088?seq=1#metadata_info_tab_contents
An interesting old article on leaf springs and shocks.

So it says that the reason you do not want friction between leaves of springs is that the friction is greater on compression than rebound.
This is the opposite of what you want. An easy compression of the spring is required with good control of the rebound.

 

[WHN]

I’m not sure that I agree with you. Shouldn’t a spring be harder to compress and when no longer being compressed quickly go back to its original condition? The shock absorbers softening the movement it both directions.

Interesting to think about.

Enjoy.

 

[Jack Shaft]

Makes sense.. The spring by design aides rebound seeking its relaxed position...under compression you work against it. Polishing and lubrication the leaves makes a big difference in how the car reacts..

 

[Patrick L.]

Grinding out the wear grooves from 9 decades of use and a good lubricant along with a good set of shocks sure helps these old monsters ride 'more better'.

I think the springs and shocks tend to work opposite each other, but, no matter, as long as the ride is good.

 

[MikeK]

As to whether you want dampening of spring action to bias from 50/50 in favor either compression or rebound depends on your particular roadways. Do you have more bumps or more potholes?

 

[Patrick L.]

Our shocks have a 60/40 or so bias/differential. I think the bias is on the rebound if I remember correctly. But, no matter. Good springs and shocks makes a difference.

 

[Gene F]

I replaced my front spring some years back, with a nice one from Snyders. What a difference.

My shocks are the good ones from the later RainMakerRon.

My car rides well, and I need not have a death grip on the wheel.

 

[GeneBob]

You want to be biased to damping more on the rebound stroke. A bump on the road sends a shock into the car through the spring and heavy compression damping just adds to that shock. You want the spring to compress easily to reduce the shock to the car, then absorb the energy on the rebound. I don't think stock Model A shocks have any bias. However, I rebuilt my rear spring and replaced my front spring along with getting the shocks rebuilt by John Holland and it drives much better now.

 

[buckwild 27]

Mine didn't have shocks on it when I got it. Bit of a bumpy drive

 

[Patrick L.]

There are CW and CCW 'tonnage' specs for these shocks. But I'm not sure which is which, can't remember, but, I'm thinking the higher poundage spec is on the rebound. I've changed fluid weight as the shocks wear to get about the correct spec. Its been quite some time though. I used to be fussier.

 

[jack wingard]

I'm not sure what it is called, but the two working with each other. It is about comfort plus keeping the tire on the road to maintain control.

 

[Kevin in NJ]

It is pretty simple to diagnose your cars suspension.

If you do not have shocks and can drive over 25 MPH then your springs need work.

If you put good springs on a car and try to drive over 20-25 MPH the car will feel and be uncontrollable. It is not a very good feeling.

 

[updraught]

As to whether you want dampening of spring action to bias from 50/50 in favor either compression or rebound depends on your particular roadways. Do you have more bumps or more potholes?

To me 50/50 would be a sports setting mainly for handling.
For ride you need little resistance on compression and plenty on rebound.
Well, not too much on rebound that the wheels don't come down fast enough.
You can adjust up Koni shocks (rebound) till you feel the wheels not come down fast enough, and then back them off a bit. You'll get a smooth ride.

 

[Pete]

The ideal situation is to have NO or very minute friction in the spring as in coil springs or torsion bars with all of the damping done with the shocks. Anything that reduces friction in springs is good. There is NO perfect shock for a smooth ride on all road conditions. Very rough or uneven conditions require more suspension travel (lower spring rate for given weight) with the corresponding longer travel shocks. The shock bias will depend on how much control is required in the operating speed range.
A comfortable ride to one person may seem quite harsh to another. You can get all kinds of test data from a shock dyno to determine what bias percentage and stroke is needed for a given car but if the person driving doesn't like the ride, it is wrong for him.

This precisely why you will find a rack on the wall in a sprint car trailer with at least 50 shocks in it. It is a "try it out" thing to find the right shocks.

If you want your model A to ride like a 1969 Ford LTD (judged the most comfortable) it will be a costly clinical trial.

 

[arnhemmer]

I've always wondered why they are called shock absorbers while they mainly act as dampers.