I was surprised when I got back some synthetic motorcycle Amsoil analysis back from Blackstone Labs. They told me I could probably use it out to 12,000 miles in the analysis report. Never heard a squeak out of the clutch on that bike either using it.
This year I may skip the oil change in the K1200GT and make it every two years. The S1000RR gets an annual change as it gets used more the the K1200GT does. I don't look at bike mileage that much anymore as I doubt if I do 8K miles on either so annual it became (Generally, in late winter before prime riding season.). The S will go off warranty this year anyway so it won't be that big of a deal for that purpose.
I sometimes think we over-medicate these bikes as it is. I doubt if I've ever changed ABS car brake fluid either. Auto tranny went to 100K miles before it got touched. When I had my Harleys, I would change them every 1,500 to 2,000 miles. Some at the local Harley shop go all anal when they can't be fit in within 20 miles of their due mileage service. Some do it far more often and clean them with a Q-Tip too. Some of the S guys do it after every race which is often less than 100 miles too. Whatever.