Patrick, you should look into the Avenir expandable seat wedge bag. I use one on my CAAD to carry a spare tube, a patch kit, Park tire tools and inflator, a house key and 3 spare CO2 cartridges. It isn't even expanded now, I have managed to pack carefully. The phone is in a zip-lock bag in a jersey pocket. If I were to expand it I could easily put a folding tyre and the phone in it if needed. They are inexpensive, I got mine at Amazon, maybe this would help. I have had to fix flats twice this year, used the spare tube both times and finished the ride comfortably. Hope this helps out some.