What's your choice?
Just getting into cycling and looking to purchase one of the options

Pump is better unless you are in a big hurry.

PS get a pump with a flexible hose that connects to valve stem. The ones that engage directly do work but when you are using them they can stress the valve/tube connection and cause a tear. Which will cause many tears.

Pump Best. Use CO2 when in a hurry.

Do you mean for pumping up before you leave the house, or when you change a tire/tube at home? Or, when you get a flat out on the road mid-ride?

For the former…I don’t know why you’d want to use anything other than a floor pump (or maybe a compressor). For the latter,…well after 40 years of cycling I just finally decided to try CO₂ and carry that with me for mid-ride flats about three years ago. I can’t believe I waited that long. The CO₂ is SOOOOoooo much easier than a frame-mounted pump. And not that expensive. The inflator valve can be obtained for +/- $20. And a box of 12 CO₂ cartridges was about the same…I think…probably less. I’m still working on the original 12-pack I purchased when I made the switch. That being said…I still can’t bring myself to leave the frame pump at home. I carry two CO₂ cartridges with me and have never needed the second one. But I know that the first time I don’t take the pump that I’ll end up with two CO₂’s going “pffffsssstt” and end up with no way to inflate.

Dan

When I still used tubes, I used CO2. So much faster... but with tubeless, the pump mostly doesn't get used, so the rare occasion that I need to spend the time seems less important

With tubeless I carry a pump because CO2 and tubeless sealant supposedly don't play all that nice together.

I have a Mountain Morph pump, which is the fatter version of the Road Morph for higher volume/lower pressure. It's pretty bulky. I chose it specifically because it has a foot that folds out to use it on the ground. I had a heart surgery a few years ago and for a long time after it was pretty hard to squeeze my arms together.

Very much personal preference- some people around here will carry a lot of spares/tools around just in case, others are ok going without and accepting the risk that needing a lot of that stuff is low. I average a little under one flat per year over the last decade, so the convenience and packaging of CO2 works well for me, and has been reliable. For someone that flats much more frequently or goes on longer rides, a pump and more spares/redundancy make sense.

Whichever option you go with, if you aren't already comfortable with it, practice getting a flat at home so that you aren't learning on the side of the road, or realizing you don't have all the tools you need.

CO2 is best unless you have loads of time.
Assuming this is a question about what to bring on a ride, and not at home, I think a lot depends on what tire/pressure you're riding. A minipump kinda sux if you have to get to 80-90+ psi, so then you're considering a larger frame pump.

FWIW, I have both. CO2 (2x), plus a little mini-pump which would be my last recourse and I'd be resigned to probably finishing my ride about 20 or so PSI below what I'd want to be using.

i so have a mini pump and i do need to go to 80-90. i cannot pump it completely in one go, i need about a 3-5 minute rest to get reasonably close and no gauge to know for sure but also don't really care, just want to get back in the saddle as soon as possible.

I carry both. Co2 is quick and convenient but the cartridges get heavy quick when you start adding them to your jersey pocket so I carry a couple cartridges and a mini pump. It comes in handy if someone else needs some air along the ride as well.

...” I still can’t bring myself to leave the frame pump at home. I carry two CO₂ cartridges with me and have never needed the second one. But I know that the first time I don’t take the pump that I’ll end up with two CO₂’s going “pffffsssstt” and end up with no way to inflate....”
I figure it is not that much of a hassle to carry a mini pump. After helping too many people who blew through their CO2 I prefer not to be stranded, especially if it means getting my wife to pick me up 40 miles from home!

Same.

I can't say which is best, but I use CO2. I'll add that I rarely flat. Have had 3 in the last two years & they were all on the same ride.

A quality mini-pump is the safe bet. CO2 is optional for speed, but I don't bother.

I carry both but I use the pump more often than not.

Pump and second on the flexible hose. I carry CO2 just in case I get caught by inclement weather and am not in the mood to pump the tires. Luckily that haven't happened yet.

Co2.

If you go the CO2 route, put the cartridge in a piece of old inner tube as insulation. When you use the inflator things get really cold really quick. The tube will give you just enough time to inflate your flat before your fingers get frostbite. Also practice once or twice at home so you know how it works before you rely on it out on the road.

I carry a Lyzene road drive pump and love it. At home I have a cheap Serfas track pump. I also carry a spare tube and a patch kit. I have not tried tubeless yet.

great idea. And also suppresses noise in the saddle bag too.

The CO2 inflator I used to carry had a sleeve that screwed on for the cartridge. I didn't think about the cold part but it also allowed use of either smooth or threaded cartridges, or the 12 gram cartridges from the bb gun aisle. It had a Slime brand sticker on it but I've seen the same one with other stickers

PDW Shiny Object ftw

^ I've got one of those too, a quality piece of kit.

If you do go the CO2 route, get an inflator with a dial like the above (not a "trigger" or simple on/off switch). This allows you to control the flow rate when inflating the tube again.

Personally I have a small Lezyne frame pump, then CO2 in the saddle bag. Tend to use CO2 when out on the road as I want to get back riding quicker.

I have the Same...

I prefer a pump, and a full-size one at that, but many modern "compact" frames can't handle a full size pump. That said, over the years I've managed to injure both my shoulders and now have difficulty pumping to full pressure. So, now I carry both a pump and CO2. Start out with the pump, top off with the CO2. And if, heaven forfend, I run out of CO2, I can still get enough pressure in the tire with the pump to carefully ride home.

Or just go tubeless....