That is odd - on my 88 R100RT I ran tubeless, andmight lose 3-4 pounds of air in 2 months' time. But any of my airheads running tubes ( use the metzler rubber tubes as they seem pretty durable/thick) I will lose about 10 pounds per month. Usually the tubeless tires hold pressure better. My Kawasaki Concours runs tubeless, and it might lose 5 PSI over the course of the whole winter - which, considering the temperature extremes it experiences, I consider exemplary.