Good eye. On my day rides I simply carry 1 21" tube for the reasons you suggested. On my multi week trips I actually carry 3-4 tubes. Sounds crazy doesn't it? Why you ask?

Number one is often there are no replacement tubes available nearby in nations that consist of mainly scooters where I am in South East Asia. So if I use my one spare tube but have another two weeks of riding and no spares anywhere it gives me a case of the worries. Another reason is I have an uncanny knack for exploding tubes. My friend laughing at a tube i ruined.



I actually even tried the Nuetech Tubliss system for 4 years to eliminate the need to carry spare large tubes. It saved tons of room and i was a happy camper. However I could never get them to seal reliably enough to warrant taking them on my long range trips.

Even on a short four day trip the Tubliss tube punctured forcing me to utilize a traditional tube.