I carry three 12 oz in my seat bag along with 2 tubes, glueless patches, cell phone, copy of my DL & Insurance card, a few $$$, a little change, and a multi tool (which I've never used). My inflator won't accept a 16 oz I don't believe. After a few weeks layoff during the winter I checked my gear and found a punctured cartridge in the inflator - it still had some pressure to it.