fork oil is a personal thing... kinda like shoes
what feels good to some doesnt feel good to others!!!
i personaly use 10W its a little soft but it doesnt hydro lock as easy... but ridding 2UP it deffinetly needs something thicker (15w or 20w)
what i would do is get some 10w, 15w, 20w get a graduated cyclender and try the 10w! put about 50 miles on it! then drain and do the same with 15w.... ect... then see which one you like best... ALSO make sure your front spings are good mine were saggy and i replaced them with progressive springs from DYNOMAN.net once you find the right oil.. toss the others out
and buy some extra oil of the Weight you like and at the beggining of the season change out the fork oil
happy dampening