Hows this for a late reply! Posting in case this assists anyone else.
I've just been researching fork oils and centistroke ratings. I have no idea what oil is in mine as it was replaced around 3 years ago by the bike shop. Quite a few recommend Sikolene 5w - I've found it hard to get some in Australia, however I have managed to get some and will replace the oil soon.
I'll just use Penrite or Motorex next time (same price for fully synthetic).
CST rating
Sikolene 5 w 22.3 mineral
Penrite 5w 20 full syn
Motorex Racing fork oil 5w 21.8 full syn
The original oil, I believe is yamaha 01 has a CST of 15.6, a lot of people seem to report oils that are generally rated 10w are too heavy and cause harness in the forks - the ones I've seen mentioned seem to be a CST rating of around 30-40
So from what people report a CST of around 15 is a bit soft, 20 ish pretty good and 30 or above a bit harsh for average riders. This is only from my own readings/research on ze internet.
