workingdog
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- #581
More thoughts on spring rates.
So, I have 9" of squat to get to ride height. I'm at about 600 lbs per tire front and rear. if I add 250 lbs for gear and 250 lbs for me, then I'm at 730 lbs per tire. Remember there are two springs, the total squat of both has to total 9" to get to my ride height. A 150 lb spring squats 4.9" at 730 lbs. So 2 150's would squat almost 9.75" - too much. A 150 and a 175, total squat is 9", exact.
Right now I'm running 250's top and bottom front and back. To get the rig to right height with the 250's, there's several inches in which the springs are loose at full droop. And, it rides very firm. Great for on the road, but not what I want off road. I have a pair of 12"'s on front, which leaves several inches of coil over exposed, and a 12" and a 14" in back, which fits nice at right height with about an inch of shock to spare. Since my final shocks will squat to the same point, 1 12" and 1 14" should be good.
So, I'm thinking about ordering the 150 and the 175's now, get them on, and if they end up being too light, because the rig ends up weighing more than I think, I can always change the 150 to a 200 if needed to bring the ride height back up.
The big variable here is the weight of the flatbed.
The only thing I really don't know anything about is spring length. with 12" and 14" springs, I have zero preload. So I want some. Should I be running 2 14" springs and an inch or 2 of preload? and, what does the preload do to my calculations. I assume it just takes inches right out of my squat that I have to add back by using softer springs.
So, I have 9" of squat to get to ride height. I'm at about 600 lbs per tire front and rear. if I add 250 lbs for gear and 250 lbs for me, then I'm at 730 lbs per tire. Remember there are two springs, the total squat of both has to total 9" to get to my ride height. A 150 lb spring squats 4.9" at 730 lbs. So 2 150's would squat almost 9.75" - too much. A 150 and a 175, total squat is 9", exact.
Right now I'm running 250's top and bottom front and back. To get the rig to right height with the 250's, there's several inches in which the springs are loose at full droop. And, it rides very firm. Great for on the road, but not what I want off road. I have a pair of 12"'s on front, which leaves several inches of coil over exposed, and a 12" and a 14" in back, which fits nice at right height with about an inch of shock to spare. Since my final shocks will squat to the same point, 1 12" and 1 14" should be good.
So, I'm thinking about ordering the 150 and the 175's now, get them on, and if they end up being too light, because the rig ends up weighing more than I think, I can always change the 150 to a 200 if needed to bring the ride height back up.
The big variable here is the weight of the flatbed.
The only thing I really don't know anything about is spring length. with 12" and 14" springs, I have zero preload. So I want some. Should I be running 2 14" springs and an inch or 2 of preload? and, what does the preload do to my calculations. I assume it just takes inches right out of my squat that I have to add back by using softer springs.
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