Moto Grand Prix
Mile High Moderator
Join Date: Jun 2014
Location: Parker, CO USA
Here is a thread about changing fork oil in the 955i bikes. Should be the same for your RS.
As far as brands, you'll get a ton of opinions. I generally use BelRay or Maxima but anything that meets the specs you need should be fine.
The weight of oil should be what is important though. Depending on your weight, riding style, etc. I usually go with 10w, but I weigh 190#.
I probably need an intervention because of the bikes that keep 'following' me home. Current garage:
2001 Daytona 955i, 2 yes two, 2003 Sprint 955i STs (spouse rides one), 2016 Speed Triple, 2001 Kawasaki ZRX 1200R