Flat ride or pitch?

https://www.degruyter.com/downloadpdf/journals/nleng/1/3-4/article-p101.pdf

https://m.youtube.com/watch?v=ZR0W0XyxN_Q

so, if a flat ride is so great, why aren't all vehicles designed this way? I'm not arguing logic, just don't understand the inverse. Pretend I'm 5yrs old. 

What does the suspension geometry want?

In reply to Vajingo :

Most modern street cars built after the mid-90's are set up this way from the factory. People don't realize it because most cars come with progressive rate rear springs, but if you stick an OEM rear spring on a spring tester and compress it enough to simulate a real bump, you'll see some shockingly high rates come up.

In reply to boxedfox (Forum Supporter) :

Nice. That's what I thought. Just didn't know if there would someone that would say "you can have a pitched ride for X reasons"

Pete. (l33t FS) said:

What does the suspension geometry want?

Not sure. What factor are we after? 

Vajingo said:

That's what I thought. Just didn't know if there would someone that would say "you can have a pitched ride for X reasons"

I haven't found any analytical approaches to suspension tuning that don't target some degree of flat-ride as a starting point.

Vajingo said:

Pete. (l33t FS) said:

What does the suspension geometry want?

Not sure. What factor are we after? 

Well, here's what I see.

What if you had a body on frame car and lifted the body 3" in the back.

Same car, but lift the body 3" in the front.

In both cases, the suspension geometry and everything else are identical, but one is raked heavily one way and the other is raked the other way.

So...  What does the suspension want?  The body is just the body.

In reply to Pete. (l33t FS) :

This isn't front vs rear ride height, or rake, it's front vs rear relative suspension stiffness. Flat-ride refers to when the rear ride frequency is 10% to 20% higher than the front ride frequency. The video linked above goes into greater detail explaining some of the reasons behind this.

In reply to Driven5 :

Oh.  Yeah, that was actually covered somewhere in either Puhn's book or .... hell I can't think of his name, was a GM chassis engineer for years.  Basically for best ride you want a somewhat higher spring frequency in the rear than the front.  This is why cars generally have monstrously stiff front stabilizers compared to the rear, if there is one in the rear at all.  The front springing is softer, relatively speaking, so to get the roll distribution right that gets made up with stabilizers.

Edit:  Herb Adams.  He had some weird ideas regarding anti-s, if you take his word literally then antisquat and antidive are "permanent" effects and not transitional.  To read his words, if you had 120% antisquat then you would have 20% more weight on the rear wheels than the car weighs, the whole time you are accelerating.  Other than that, it's worth a read.  Plus there is a pictorial on the correct way to cut springs.