Rear suspension lay out

I'm at the same point with my 650 project...trying to figure out where to mount the shocks to my SV650 swingarm and how long they should be...and the affects on the rake/trail.

from what I’m seeing now. i need shorter shocks for sure.
I just realized that since my swing arm is lower than it should be,(about 3.5" due to the shocks being too long) it is stretching the hell out of my chain. As the shocks compress over a bump , the chain gets tighter. If I adjust the chain to have 1.250" of slack and then compress the shock 3", the chain is sprung very tight. This explains why my chain has stretched sooo much.
If the swing arm pivot and axle are in line with the output shaft the chain will get looser as the shock goes up or down.
if the arm is above, or below this line the chain will get tighter.
Therefore, this seems to be the starting point. then u can find the optimum angle to get a progressive spring action (as the shock compresses it gets harder to compress, rather than linier.)
Thanks for the help Leon. i sent u an email.

happy to help,mark.

leon holmes