Once again, as I swing my leg over a bike with a freshly repaired flat tire, I wonder why I ever try CO2 inflators.

This flat happened, as they like to, at night. I left the bar, said goodbye to my friend, unlocked my bike, and confirmed that the curiously soft tire noticed on the ride over had matured into a sad limp tire casing and a rim sitting at sidewalk level. Sigh. Take off the backpack, pull out the bag of fix-it stuff.

This is my roadie bike, so it travels with a minimalist kit. A single tool, two levers, one tube, one CO2 cartridge, and an inflator head that I must have chosen because it weighed 5 grams less than its peers. Five minutes later, I'm holding a freezing cold cartridge, a bag with no more cartridges, and a not-fully-inflated tire. So I rode a slightly soft tire home, praying for no second flat. And in the dark I rode through a puddle of glass, and prayed even harder the rest oft the way home.

If a single cartridge won't fully inflate a 25 mm tire, then I should carry two. Then I'll be prepared for a single flat. Only one. A second flat will leave me calling the wife.

Yet two cartridges don't weigh substantially less than a mini pump, which will happily inflate tire after tire, with only a patch or two needed.

Why do I keep being seduced by 40 grams less and nothing sticking out of my jersey pocket?