CO2 Vs Mini Pumps What’s best for roadside inflation?

For many new riders, preparing for roadside repairs can be a stressful situation. That’s why we recently wrote up a guide for new cyclists looking to fill out their flat repair kit. We touched upon inflation, including mini pumps and CO2, but we wanted to dive deeper into which you might want to use in a given situation.

We spoke with Rich Dillen, a bike commuter, bike messenger and bike racer with decades of experience to learn the benefits, drawbacks and best uses of both CO2 and mini pumps.

Tell us about your history in cycling.

I’ve been commuting by bike since I was in college in the late ’80s. That was back in Ohio where commuting by bike sucked six months a year. From there I moved to Charlotte, North Carolina, and shortly after that got a job as a bike messenger and pretty much have been doing that and that alone since 1996.

Image by Lee Flythe

I am still commuting and doing the bike messenger stuff. And I started racing mountain bikes back in the early ’90s. I have done cross country beginner stuff all the way to the far end of 24 hour racing and 100 milers. I’m on my bike any time I have free time.

When it comes to changing a flat tire, one aspect people think about is how to inflate tires. There are a few options, including CO2 and small hand pumps. Do you have a preference?

I have five bikes and just about all of them have their own setup. I’ve got such a large collection of different hand pumps I’ve acquired for one reason or another, as well as floor pumps, and different CO2 heads.

For my commute to work I will just have CO2 because generally I don’t leave myself a lot of time for a flat tire on the way to work, and it’s way faster. But while I’m at work, I carry a pump in my messenger bag. I would love to have CO2 just in case I’m in a time crunch and need to fix a flat quickly, but we aren’t allowed to take them into the courthouse, and I got tired of hiding them in bushes outside to get past the Xray machine.

If I’m racing, then I am carrying straight CO2. I have two CO2s and two inflater heads because I have had inflater heads fail on me. I can’t figure out what goes wrong but something does.

I have a pump for my mountain bike. That’s the bike that someone is going to get a flat on if I’m riding with friends. If one of my buddies gets a flat, I’m not going to hand him my CO2 that costs $6 or $8, it’s like, here is a six-pack of beer, here you go.

With that kind of cost, what are the benefits, other than speed, for CO2?

Other than speed, the convenience. I have CO2 on all my bikes just in case everything goes to hell and I need the redundancy. I carry as much as I can with me as far as fixing flats because that’s the one thing that’s going to happen more than anything else.


With mini pumps you will also exert yourself to get a tire running 80-100 psi to full pressure. I’ve never used a mini pump and been pleased with the experience. They are all taxing. If it’s Charlotte and 95 degrees with humidity, eventually you’re going to pass out if you’re not careful.

There are different kinds of hand pumps, some the pump tube attaches directly to your valve, other times there is a rubber hose to give you a bit of flexibility. Do you have a preference?

For my mountain bikes, I have the extendable hose pumps, like the Topeak RaceRocket. Those are nice because when you are getting really crazy pumping 50-100 times you don’t have to worry about possibly doing damage to your valve stem. You can put a tear in where the valve stem connects to the tube if you are not careful.

The only downside is, if it’s a tubeless system, you have to make sure the valve core is tight. Otherwise, when you back those off you can lose your valve core and lose all the air you just put in. But, luckily Topeak puts in a valve core tightener on each of their pumps and just about every multi-tool nowadays has some sort of valve core tightener.

On my gravel bike and at work I don’t bother with the hosed pumps. It is easy to find a park bench or platform where you can lay the wheel down so when you put that pump on you can stabilize it against some solid object so you’re not yanking up and down so much. It’s just harder in the woods. You’re looking for the right rock or the right root. It’s just not worth it.

Any other tips for riders new to doing this?

First of all, learn how to fix a flat before you have to, even if it means practicing in your living room, pulling a tire off with or without levers, making sure you don’t ruin a tube.

That does mean practicing with a CO2 cartridge that is going to cost you $6 just to try it once. That cartridge will be wasted and you will be recycling it. That kind of sucks, but you should know what you’re doing. There are many different types of CO2 inflators, some are press on and the air comes out, some are thread on then you have to back it off to let the air out, some have dials on them. Knowing which one you have and how it operates is key. Once you start letting that thing go, if you don’t have it on very well there goes $6 and you still have a flat tire. That really sucks. 

And if you are using a pump you don’t want to get in the mindset of being in a hurry, it can damage your valve stem and it’s going to take a while. Just get familiar with the equipment.