Technical How to design suspension system to obtain desired ride height?

Agree. Seen my OME springs settle over the years on my off-road rig. These springs are almost 100 yrs old, so guessing they’re already tired. The ch***is is far from its final curb weight, so it’s just to give me an idea. Will be interesting to see if it matches the deflection given by the formula I used. By plotting the deflection with different ch***is weights” I can plot a curve/line, and then guesstimate what deflection might actually be at CW with me in it.

 

But I find it doesn’t matter if the spring is new or old, it will settle. After having it in and out of the mounts, it seems to take a few miles to get back to its happy place.

 

For sure. I’ve read somewhere folks placing something between the individual leafs (near the ends?) to aid in movement between each leaf. Supposedly it smooths out the ride. These springs are heavily pitted.

 

Finished off the U-bolt plates and spacers and got everything installed. Jacked up the ch***is enough to get some wood supports under the spring eyes. Lowered the ch***is slowly until it settled down as far as it would go. Had to add a 1/4” thk piece of wood under the PS spring eye as the two eyes were not at the same level as the DS side eye touched the wood support first. Not sure if it’s the floor ch***is or springs. The DS spring seems to have a sag or flat spot just after the eye. I noticed that when I took it all apart. I had jack stands at the rear that were about 7” rearwards of where the rear axle centreline should be. That would likely bias a bit more weight on the front axles than it would be if the stands were under the rear axle. Total deflection was 1.5” on the DS and 1.25” on the PS. Not 100% accurate, but pretty close. Tube axle is on a 0.5 degree slope.

 

Should mention that I had the front and rear axles (no hubs/drums/wheels mounted) sitting on top of the ch***is, so that was adding weight that really shouldn’t be there as it will be part of the unsprung weight. Pic of the DS spring with sag or flat spot after the eye.

 

It might help if your 3rd leaf was a little longer or rearch the spring to get the flat spot out?

 

Front spring is a Model A traverse front spring just cut in half. Plenty of folks still use the stk Model A spring when they add their flathead to their Model A ch***is. So hoping it would sort of work. For sure by cutting it in half and clamping down the first 4.5”, I’ve lost some arch in the original spring design. The spring has about another 1.25” of travel before it completely flattens out which is probably not good considering I still need to add my body weight (250 lbs - 6’-6”), plus say another 200 lbs of stuff incl fuel. Not sure how much weight of the that would transfer to the front axle, but ***uming a 50/50 weight distribution, that’s another 125 per spring. Maybe I can have the springs re-arched. Another possibility is using a 2” wide spring. @Stogy and I are going to check out a 1920 Chevy ch***is today that has 2” wide springs both front and back. Interesting, it seems the front springs are at an angle as you mentioned. lol!
As far as anti-dive goes, I’m really not thinking about that. Watched a few vids, and read a few forums, and info is all over the place. Read one post that mentioned the instant centre doesn’t even apply to vehicles with leaf spring suspension.