When I travel more than five miles, I carry a spare presta in my pack and 2 adaptors for filling air. all I need is one . I also carry an emergency pump . At home, in my tool box, I have 6 spare presta tubes . Cyclists should not have to deal with gas stations..my bike shop told me that is all their gonna have soon, and I don't blame them. Presta tubes are an incredible muchly needed improvement and I thank God for whoever it was that created the presta. After typing this I'm going to add another preasta to my pack. Adaptors are only a dollar,-get lots of them.