I started looking into replacing the front springs on my 2007 S4Rs but I needed to know what was in there now. After calling a few dealerships to see if they new the spring rates (no luck) I decided to give Ohlins a call. On the bottom-inside of the fork leg there is a part number that refers to the OEM spring rates on the bike. They are as follows:
FG836 = .95
FG8360 = .95
FG338 = .85
FG3380 = .85
To get a replacement Ohlins spring you use the following part number:
4744-##
The ## refer to the spring rate weight. For example:
4744-95 would get you Ohlins .95kg springs.
4744-05 would get you Ohlins 1.05kg springs.
Hopefully this is helpful.