What I like to do is first get a base line for stock. I do this to have something to gauge the change. Way to stiff on the rear is how we look at the base line then come up with a corrected number.
I take the balance and ratios to come up with a number then use a % of change. In this case rider weight only.
Spung,unsprung,ACF, rate,balance,LR(MR),ST. This formula provides the number for spring rate corrected.
ACF= angle correction factor. Basically cosine of shock angle. For % or multiplier, cosine or inverse consine.
This provides a straight line equation. By using the numbers I posted Amy one can use the online calculators or do the math themselves. I found in my work on my bike the on line calcs are to stiff.

Rider weight x mutiplier, then use the other two numbers to get spring rate. You have to use the inverse of the two numbers I posted to work the problem backwards.

I'll work up examples if you don't get it. This is back yard hacker math, do sorry if it's kinda wierd.

I take the LR and turn it into a usable MR. What I do is find the shaft travel for 1" of wheel travle. 1/1.5 =.6666. This is number you use for MR. Make sense? Remember I could be wrong.

LOL ----- holyfk
I'll just wait for the charts.
Great work adnoh thx.

Working on chart. With one single rate spring it's not looking good. For that 135 lb guy with 15% sag
Does the stock have any sag with stock spring. Some one jack up and then lower push down a few times and role back and forth and see what it is if any.
Thanks.

Is this one?

Spec

I think it may help.
This would allow for a softer rate like 140 and allow for the sag with out to much preload.
With your weight and balance and sprung weight of 180 it could give you the sag you need with some peload adjustability with a bottom out around 420 to 460.

I realize that we are still getting shorter but I found these dual rate springs. Progressive Spring 03-1365B. 9.87" long. 1.85 ID. Rate is 120/170. Sounded interesting anyway. Saw other rates. 70/120, 140/200 etc...

$77 on Amazon Prime...

need info, see pic
Thanks

Thank you
The nbers good enough. I just need them to done check what I come up with. Working out a couple of bugs then ready to post. Using a single spring I have a coplue of different set up for you to look at. One with a 140 and one with a 100. It will require different solid spacers. No big deal since they can be cut to lenght. I'm really leaning toward an100or 120 that is why I need the numbers.

I'll enter the info tommorow and post if it works out.
Thanks for being patient.

CO, it will bottom out at the listed BOP. Compare to the stock spring.