Will the RS see a surge in sales and if so will there be enough supply?

[Ray]

Agree - you have the right to feel left out in the resumption of this old practice of putting a duckbill valve at the low point on your swingarm - just in case you find some high water to run through.

So they used to put the duckbill valve on swingarms as a matter of course before? This being my first shaft drive I was not aware of that. I wonder why they stopped given it is a low-tech solution. 

Good pick-up. I shouldn't write when tired. 

Although I recall a Paris-Dakar model at the shop with a one-way valve in a drain hole in the swing arm in the 90s, I guess this was simply aftermarket garage work. I went back to check the old microfiche and established that this was NOT a factory practice. My prior post has been edited.  

(This is also my first R bike, though I had a couple of K100s to get used to the drive shaft.)