http://mahonkin.com/~milktree/motorcycles/fork-oil.html
Google "Suspension Oil Viscosity" and you'll turn a few charts up.
Remember, the viscosity will also impact on your valving. A thinner/lighter oil will flow quicker (faster/softer compression, and faster rebound too).
Silkolene 05 is too thick 43@40C.. The 02 wouldn't be a bad choice if you could get your hands on it. 17.94@40C VI260. From here (
http://shop.penskeshocks.com/files/d...ct%20sheet.pdf)