Don't put tubes in tires designed to be run tubless. It's a sure fire way to guarantee premature tire failure. Hwat happens is the friction between the tube and the inner impermeable liner of the tire causes exessive heat buildup, which degrades the rubber in both the tire and the tube. Usually what happens is the tube will fail, causing pressure loss, and also the sidewalls will deteriorate, causing sidewall failure. I've seen far too many tires fail because someone stuck a tube in a tubless tire. The failure time is increased with highway use. I've seen them go with under 100 miles after the tube was put in.
