As far as I know the fork oil has never been changed in my Vfr, so that's over 16 years, no leaks, I am going to upgrade the suspension, new shock and fork springs, suppose I better new seals and bushings too when I'm at it, may not be needed but better to replace them now I suppose.Well today I took my bike to work. The bikes suspension worked no better or worse than before. So for the ones that want to change their oil just because. ... my advise is leave it be unless you have a leaky seal. The manual says to inspect not replace. It was fun doing but a waste of money.... just because....
I always notice the difference after an engine oil and filter change though, bike feels tighter and smoother if that makes sense.