Picked up a 00 RC about a month ago after wanting one for quite a few years. Just over 22k when I bought it and now has just over 23k. Has Dan Kyle re-valved forks but I am trying to find out what weight it is sprung for, DK rear bottom link, Jardine pipes, flapper mod, and just installed a Internatrix TW-1000 alarm. After getting a lot of useful info here I finally decided to register so that I can hopefully give a little back.
Do you know if Kyle Racing only re-valved or also re-sprung the forks?
You could ask the previous owner.
According to Race-Tech, The SP1 forks had .95 Kg/mm springs.
If Kyle Racing swapped out the springs while re-valving, they probably used Ohlins fork springs.
Ohlins scribes the spring rate on the top face of the spring along with their part number, so you'd have to remove the fork and remove the fork cap and spacer to view the spring face.
Ohlins always rate their springs in Newtons/mm (N/mm)
Here's a photo of an Ohlins fork spring in my fork.
The number is 04745-11/L148.
The 04745 is the part number, the -11 is the spring rate (11 N/mm), and the /L148 is manufacture date (14th week of 2008).
Here's a couple of handy sites for weights and measures conversions.