Beautiful day yesterday so I decided to go out for a long training ride (3+ hrs) instead of spending 2 hrs on the trainer. Was 3/4 of a mile from wrapping up and came across and older man with a flat tire in front of a bike shop that was closed for the new year. He had a hybrid bike with 700c tires but with schrader valve tubes. I always carry a C02, tube, and tire levers with me so I ended up fixing his tire using my tube and sent him on his way. Exactly one block after getting back on my bike my stomach started to sink when I noticed a feeling I am very familiar with. I had a flat rear tire! Ended up walking back sock footed to the start point thinking about how to avoid that situation in the future. I was glad to help him and would do it again but shot myself in the foot in a manner of speaking. I had patches but no way to inflate since I used my C02 cartridge. I could carry an extra tube and C02 but thatās a fair amount of weight/bulk. What are the ODDS!
Funny side note: when he removed his wheel from the bike he pulled a full size wood chisel out of his jacket to remove the tire from the rim. I quickly shut him down and produced a tire lever that we ended up using. Hopefully we both learned a thing or two from that encounter.
I carry a small pump instead of CO2. One of my wheels is road tubeless and apparently CO2 dries out sealant. And of course the pump is re-usable 
I pack quite a bit in my saddle bag yes saddle bag lol. Three or 4 CO2s, tire levers, two tubes and patch kit.
My regular saddle bag has 2 tubes,2 CO2 cartridges, 2 levers, multitool, tire boot, cash, power meter battery.
I add a pump when I plan for the long days and groups more than a few riders, and possibly a 3rd tube depending on the route.
Better to have it and not need it than need it and not have it.
Put me in the camp of multiple CO2 cartridges, plus I carry a mini-pump. The extra weight isnāt really that much.
With this combination, Iām in a position to help out every cyclist on my ride, plus any random ones stuck on the side of the road, without leaving myself without an inflation option if I get a flat (or 2 like I did last weekend).
On top of what others have posted I also pack some mini tie wraps and those garmin/cadance rubber bandsā¦ and a little bottle of sealantā¦
Unless you have someone at home ready to come and pick you up at all times, you really need to be prepared to fix more than one flat.
I carry an extra tube, minipump, patch kit, a couple of glue-on patches. I could probably fix 8 or 10 flats if needed.
The weight of multiple CO2 carts seems to line up with a mini pump so I just carry the pump. CO2 carts also seem environmentally unfriendly.
That sucks man, I would like to think karma would have got you round without a flatā¦worse case being getting the flat as youāre walking in the front door.
Luckily you were within walking distance of your home. Could have been far worseā¦ Iāve had my last flat tire halfway during a ride. Of course I was riding solo, it was cold, raining, in the middle of nowhereā¦ My pump only could get the tire half way inflated, but enough to ride on until I came at a house near a campsite. I borrowed a pump and drove straight home. (turned out the problem was the tire itself, so after a second flat tire in the same week I tossed the thing (both of them) in the trash and bought new ones (in that order) The new ones are slow, but boy do they last (10.000 km and counting)
Oh wait I had another flat tire since. but that was on my MTB when I had too little pressure and hit a rock way too hard. That was about 1 km from where I was staying, so I didnāt even try to fix it but walked āhomeā)
Good job. 
Itās always a good idea to carry a mini pump but if Iām being honest I only do it 80% of the time. There is a descending scale that I use to determine my the āself sufficiencyā requirement of my rides.
1.) Will I be within comfortable walking distance of my vehicle/home? If yes, go full pro.
2.) Will I be within cell service? If yes one tube, one co2. I can use my USAC Silver roadside assistance number.
3.) Spotty cell service? FindMeSpot with SOV. Two tubes, two CO2, mini pump, derailleur hanger, chain tensioner, LifeStraw.
So you were better off than I probably would have been! I probably would have been full pro in that situation!
I carry 1 lever, 1 co2 and 1 tube in my pocket. Didnāt get 1 flat this year. I feel like I got lucky and it might be time to get a nice saddle bag. Preferably the āaeroā type. 
Itās still really awesome you helped that guy out. 
Sucks about your flat 
I use this on all my bikes. Fits perfectly under the saddle. I can fit a MTB tube, 2 CO2s, 2 levers, chain tool, multi tool, derailleur hanger, tire plugs, tire patches, chain link, tire boot. Everything you need except a pump which goes in my jersey pocket.
The Velcro straps allow you to compress it if carrying less. Works great.
https://www.specialized.com/us/en/mini-wedgie/p/155501?color=270858-155501
Thanks. That might be just what I need.
Yup, no good deed goes unpunished.
Note to self: never help anyone, ever.
Kidding.
Go tubeless and bring more CO2.
I appreciate all the tips guys. One extra C02 would have gotten me through and I was in the city so Uber was another possible option if the trunk was large enough for a bike. Will be carrying at least two 2-C02ās from now on and a small pump if Iām out in the sticks. My other bike (gravel) is set up tubeless and I absolutely love it so far. Itās fairly new for me and havenāt had a flat yet so we shall see after I have to deal with one. I carry a plug kit, C02, and tube for that set up just in case. Air doesnāt bleed down near as much as clinchers with tubes. This is a great forumā¦Happy New year!!!
I always used to carry CO2 but here in the hot, humid south, the super-cold CO2 will sometimes freeze the dispenser to the presta valve, and the little insert at the end will unscrew and boom, youāre back to total flat again.
Mini pump for me. And a tip: if youāre alone, find a tree branch or something at chest height, and hang your wheel on it while you pump. Gives you way more oomph with no bending over.
I carry 2 tubes, a pump, tyre levers, multi tool, 1-2 co2 cartridges, patches and a chain quick link.
I also carry two CO2, sometimes even one of them is unused.
Iāve only ever used a mini pump and my saddle bag fits two tubes.
C02 is great for speed but Iāve always been put off them being one time use & the first time I borrowed one from a friend it didnāt work properly so was completely wasted.