I love the stock suspension other than nose dive for a daily driver. I was debating on a 2-2.5 spacer on the front so I didn't lose the ride. But instead, if I went with the 5100s all around, does the ride quality suffer?
There are a lot of claims for the 5100 shocks, and I would like to explain two (what I would call) misconceptions. If you see any mistakes or have any questions, please tell me.
1. Preload
People say when you increase the perch setting you are "preloading" the springs. I don't know if the term preload is just thrown around, but regardless it is the wrong term when it is usually used.
A spring is defined by Hooke’s Law:
F= -kx
This means that with a force (F) and constant spring rate (k) a spring will always compress the same amount (x). When you adjust the perch setting on the shock, you are not changing the spring rate or the total force applied, so the spring will always compress the same amount -- moving the perch only changes the position of the spring seat (making the truck taller or lower), not the "preload" on the spring.
2. Perch Harshness
People claim that at higher perch settings the ride is harsher. We've established that the spring rate doesn’t change as the perch setting moves.
The 5100 is a viscous damper meaning its damping is velocity dependent and not position dependent. In that regard, perch setting shouldn't modify the harshness because the velocity of the shock isn’t dependent on perch height.
My assumption of people saying they feel a harsher ride is a result of new shocks, springs, the truck sitting taller, sway bars effective stiffness, etc.
So spring rates are a linear expression. Do you think that the limiting factor is the amount the coil can compress? Do you think ride quality will suffer by raising the spring seat of a Billy 5100 to 2.5"?
So spring rates are a linear expression. Do you think that the limiting factor is the amount the coil can compress? Do you think ride quality will suffer by raising the spring seat of a Billy 5100 to 2.5"?
The post you responded to is over 4 years old -- sad to see that efforts to stamp out the "preload" myth were ignored 4 years ago just as they are today.
As you increase the amount of suspension lift, you lose some ride plushness because of changes to the suspension geometry. A bit more of a vertical force component is translated to the frame, which results in greater impact harshness. This would occur even if the spring rate and shock valving aren't changed. So yes, all else being equal, a 2.5" lift will ride somewhat rougher than stock -- whether it's enough to be objectionable is up to individual taste.
Raising the spring perch position limits droop travel because the suspension is extended farther in its resting position (and thus, the vehicle sits higher -- that's why it's called a "lift"). The amount that the spring is compressed under the weight of the truck remains the same.
Sounds like I’m way off base now - are we saying changing the perch doesn’t compress the spring any more than the stock condition? Essentially the spring force is at or exceeding corner weight off the bat?
I may be looking at this from too micro a level (if I’m wrong that’s fine), but the idea of that seems absurd considering the stock spring rate should be in the 600 to 700 lb/in range.
OA
With the 5100's you have more slow-speed damping and less high speed damping.
Translation: Bumps are soaked up better, and the whole thing doesn't get out of sorts on a wavy highway or nose dive the way it did before.
Plus the shocks have longer stroke than stock, which prevents the head-toss effect when the suspension tops out (like empty vehicle, just one driver).
All in all, it feels like it should have felt coming from the factory - more stable, and much less fatiguing to drive.