Yamaha TRX850 Enthusiasts Forum

You might find this useful when looking for that elusive fork oil - especially those with R1 forks and using Yamaha/Kayaba 01 fork oil.
c/ST or centi strokes or mm2/sec is the most reliable way to compare viscosity, rather than "weight"

https://transmoto.com.au/comparative-oil-weights-table/

Was made aware of this very fact a few years ago Al but never had the hard data to compare things too.
Job well done mate and some even have comparission when oil is hot too..