Just to let you know of another site I've found.

This link will take you to the tech articles. Of particular interest is the one on "Oil and Fuel".

http://www.bmwmotorrad.co.za/Web/InfoLibrary/TechnicalDIY.aspx

Always good to read the info "straight from the horses mouth". Quite a bit has been written recently about oils for K's, but for me the rule is - skrimp and scrape on lots of things, but never on oil and a filter, or coolant.
There is some psychological comfort in having changed the oil(s) just before you set off on a long tour. I like to be able to see straight through the oil to the backing plate in the sightglass - clean oil, can't beat it. Keep 'em clean inside and they'll last forever.