Since I am too uncorordinated to drink from a water bottle while I ride I must use a hydration bladder of some kind. This leaves my water bottle cage empty and I have been able to fit my folded tire into that. I also use a large under seat bag with only a Topeak alien and patch kit in it, so I have been able to fit it in there also. Of course I then have to carry my spare tubes in my pockets or handlebar bag. Yes, with 650 wheels, even on a supported ride I like to carry a spare tire.