I am stationed at Fort Bliss, TX.  I am currently TDY at Fort Jackson, SC.  I recently traded my Ninja for a Sportster 1200C.  No service records were present, so I just went ahead and changed the engine oil with standard HD 20W-50.  It currently has 12,800 miles.  At 15k, I will go ahead and switch to M1 v-twin 20W50.  The walmart here near Fort Jackson does not carry any motorcycle oils whatsoever...or anything else concerning motorcycles.  That is weird to me, because in El Paso, there is a small section dedicated to motorcycles.