3 miles into my ride this morning and I pinched my rear tire on a turn. Still trying to learn to be proficient at changing/repairing a flat in the field. I'm equipped with a patch kit and CO2 cartridges. I bought one of those Topeaka CO2 Cobra triggers. It worked fine and I was able to ride home the 3 miles for a total of 6 miles.

My questions are: Does the tube need to be drained of CO2 and filled with air? And should the repaired tube be discarded in favor of a new one?

Why did you ride back home?

CO2 leaks faster from tubes.

Patch the tube.

I air up my tires before each ride.

You may find that the CO2 will leak out of the tyre quicker than normal air---According to a thread that ran a few years ago- so just top up from the floor pump and don't bother changing it.

But the real question that we should be answering is "When was the current Air put in the tyre before the Flat" Those of us with experience have learnt that Summer air is Lighter than winter air- so did you change the air in the tyre at the end of Spring? The flat may have come from that heavy Winter air.

Yeah, I did patch the tube... With one of those stick on patches. I wasn't sure if the patch would hold up, so I rode home.

I switch tires with a guy in Argentina in the southern hemisphere at season change time. Doesn't everyone?

11:30 AM here with a Heat Index of 104.2 °F

You did good. I carry three spare tubes and do regular patching at home.

I bought the bike in June so its only had summer air. I don't really trust the patch because by the time I got home the tube was flat again. I'm going to make it a habit to always carry a couple spare tubes in my saddle bag.

What kind of patches do you use?

https://www.artscyclery.com/descpage-79002.html

I buy them by 100 per box. I have many flats.

https://priceforay.com/product/REMA-F...D-PATCHES.html

Defective tube on my last ride was my 65th road flat.

Thanks 10 Wheels, you are a good friend.

Carry enough to cover three flats on one ride.

Doesn't matter how you do it. Temp patches, CO2, spare tubes, mini pump.

You can also get a large cut where the new tube will get picnhed in the cut.
Duct tape works on the inside of the tire to cover a small cut or a tire boot.

Based upon this comment, maybe you should take a few minutes to look at this.

My first flat I sat down on some fire ants.

well, that MIGHT work, but the air circulates in the other direction in the Southern Hemisphere, making the wheels go backward. So I have to assume you were joking.

I poked a hole in a new tube the other day with my sloppy mounting of new tyre and tube. Used one of those green Slime Scab patches. Let dry overnight, but blew it off next day when I pumped up tube for test. I think hole was too big. Although on another tube, I still have one of the Scabs holding over a pin hole. Anyway got some "real" vulcanized rubber patches and repaired the new tube. I have at least one tube with four patches. (Finally found the fine wire sticking thru tyre after 3rd flat). I prefer the vulcanized patches. Apply per directions and clamp in wood vise overnight to dry. For my rides I carry 1 tube to change, taking flat tube home to patch. I only toss tube if leak is a torn seam or at the valve, as shown in pic a few posts back.

I heard that CO2 is heavier than air. My bike is heavy enough as it is.

Exactly why I carry a helium tank when I ride.

You don't need to buy tire boots. Tyvek makes good boots. You can cut sections from race numbers or USPS envelopes.

Isn't there some prize given for the best shortest story of the year?

I have had some failures with the stick on patches. Better to use the old fashioned kind with a tube of glue for permanent patches. Those will last for years.

What many (most) of us do, is carry an extra tube, stick on patches don't work very well, they are an emergency patch for until you get home, what I do is simply carry an extra tube or two, when I get a flat, I will swap the tube for the spare, then fill it. I'll stuff the spare into the seat bag, and when I get home, I patch it. Any time I replace a tire, I replace the tube. The old tube becomes a spare, that often means that I have a few spares. Which means I take the flat punctured one and hang it a nail in the shed, when there are a few there, I will patch them all. In this case I use the old style vulcanizing glue patches. It's about an 11 step process, but they never come off, if I am doing several I do all the steps up to the gluing on each one, then move on to the next, by the time the last one is done, the first is pretty much dry.

1) Using a bucket of water, find the hole and mark the hole
2) dry off the tube
3) use the scrapper tool or sand paper to make the patch area smooth
4) apply the glue
5) wait for the glue to dry, give it 10 minutes, do not try to hurry this, it has to dry on it's own. I usually work on another one, while waiting.
6) remove the foil patch cover and apply patch
7) add a weight
8) let sit overnight
9) pump up
10) repeat water test
11) remove air and fold up.

It looks like a lot of steps, until you realise that a 2¢ patch can be used to fix a $10 tube...

I had a similar experience once, except I put my helmet on a fire ant mound while fixing a flat. I didn't notice the ants until I put the helmet back on -- the flat was the best part of that day.