That would be a guideline for Michelin Siracs and Metzeler Tourances, the tires listed in that owners manual... If you want to ride "by the book", look into owner manuals of similar bikes that come with TKC80 as default tires, or see if Continental has any information on the pressure they recommend for TKC's on similar bikes or for Tenere - they are the manufacturer of that particular tire - so they know best... I also found out that running a bit lower than recommended works better for me, specially offroad.