Welcome to the site !!
The oil has to be going somewhere , My first guess would be rings , check the plug and see if it has oil residue on it , take your finger and wipe the tip/outlet of the muffler , see if any oil shows up on it , unless it is physically dripping oil out of a seal somewhere on the engine , or has Blow-By out the vent tube in the valve cover , the only other option is it is burning it ....
How are you determining it is not burning oil ??? , when you are riding , unless you are looking back at the muffler (sometimes it won't blow out smoke when you are sitting , but when there is a load on the engine) you won't be positive it is not burning it , ....... you could tape a white piece of paper to the fender right behind the muffler outlet , fold it so it sticks in the path of the exhaust flow , then ride the bike , then check to see if there is any wet oil drops on the paper after the ride ..... that should give you a indication if it is burning it .....do a good 5 minute ride , as it is obviously not dumping oil , so it may take some time for it to accumulate ....