The Fox Isolated Technology aka FIT damper has been around for a number of years in the FOX 36 forks and a few others I believe. The 2011 Fox oil volumes manual has so many colours in it now it almost resembles a rainbow: Why Fox has decided to relabel two different viscosity oils as 10wt now is something only their marketing department would have an answer for. I have a hunch that the Fox 10 weight GREEN is Silkolene 'Maintain' 10 weight which is very similar in viscosity to the old Fox 7wt/Torco RSF. We know these numbers are arbritrary so why not just stick with callit it 7? Or am I missing something. Nevertheless, they've made changes in suppliers and changes in the colour, but kept the viscosity of the oil required for legacy forks the same, but labelled it 10WT instead of 7WT. My experience is that the colour of the oil is not an indication of its OEM and I think Fox has changed the colour of its oil to distinguish between old and new. We've discussed this topic here often and it is nice to see a new perspective. This is according to Fox's master oil volume chart.įox always used the 7wt for damper and bath oil because of their open bath design,but with their new FIT dampers, they went with the heavier oil in the damper but stuck with the 7wt equivalent for bath oil. The FIT damper oil is the higher viscosity Silkolene/Fox 'RED' and the bath oil the lower viscosity Silkolene/Fox 'GREEN'. It follows that you can use the Fox 10wt 'GREEN' in both legs on pre 'FIT' damper forks. The Silkolene/Fox 'RED' has a higher viscosity than the 'old' Torco/Fox 7wt. The Silkolene/Fox 'GREEN' apparently has a similar viscosity to the Torco RSF medium/Fox 'old' 7 wt.

The 'new' Fox ten weight oils(yes there are two!) are probably Silkolene PRO RSF 10wt 'RED' and Silkolene 10wt 'GREEN' The 'old' Fox 7wt is rebranded Torco RSF 'Medium' with a viscosity of 31.82 Cst at 40 degrees Celsius. There are tables available comparing the actual viscosities of oils in Centistoke (Cst), usually at a standardized temp.

The important thing to remember here is that the 'weight' labelled on the the oil bottle does not mean it has the same viscosity as an oil of the same labelled 'weight' by another manufacturer.

Fork oil actual viscosity chart