Based on RaceTech's calculator, .85 is good for 260-285lb depending on track vs. street. For 205lb, they suggest something in the .70-.75 range.
https://www.ninjette.org/forums/showthread.php?t=231171
I had a NewGen shock on my 500 too. It's a great drop-in swap if the spring rate matches your weight. These are all really basic, non-serviceable shocks, so they're nothing special in that regard, but it is a cheap and easy respring if it works for your weight.
https://www.ninjette.org/forums/show...02#post1023302