You’re out on a beautiful day, having a marvelous ride, and suddenly you look down and you have a flat tire. Blah. Ok, well let’s get out the frame pump, tire irons and spare tube. And get ready to do some bicep flexing. Unless….
You happen to have a CO2 inflator in your saddle bag. Shazaam. No fuss no mess. What’s that? You never used a CO2 inflator? Don’t feel bad, I haven’t either. And I’ve fixed plenty of flats out on the road.
There are two basic options for pumping up a flat tire out on the road, either using your trusty frame pump or using a CO2 inflator. There are pros and cons to each.
Frame pumps
I always have a frame pump on my bike, and I mean a real frame pump about the length of your top tube, not a 6 inch “mini”. 50-60 pumps using such a frame pump should achieve reasonable tire pressure, maybe a bit more for the rear tire where you want maybe 85 lbs to avoid pinch flats from hitting bumps.
Frame pumps come in different lengths to fit on your frame. Some fit underneath the top tube (the beam from saddle to handlebars) , and some on the down tube (where your water bottles are). So when you buy your frame pump, make sure it actually fits snugly, especially if you plan to secure it along the top tube. The length of a top tube on one one bike may be quite different from the next. For good measure, I use a velcro strip to anchor my frame pump tothe top tube because riding over railroad tracks or cattle guards can shake them loose.
The big advantage of a frame pump is you never run out of air. You might run out of spares and have to resort to borrowing spares from passing cyclists or using a patch kit to patch a hole. But you always have air. Also you can pretty much control how much pressure gets into the tire, that is if you are willing to work at it long enough.
The big disadvantage of a frame pump is it is a tiring and time consuming process to pump up a tire. The first 30 pumps are easy because there is very little pressure to push against. Over 60 pounds is when you have to work hard. Be careful not to be push too hard against tube valve when pumping the last pounds of pressure. I use my left hand to hold the pump and valve down and minimize the torquing on the valve stem. Some frame pumps come with a decent handle to make it a bit more comfortable to pump high pressure into a tire.
CO2 Inflators
A CO2 inflator is a device that fits in the palm of your hand. You attach a small cartridge (about 2 inches long) of compressed CO2 to it, and then place the ‘head’ of the inflator (sometimes called the nozzle) onto the tube valve. There is usually a little button to release the CO2 gas in the cartridge into the tube, and presto bango! The tire is instantly inflated. You cannot control the exact pressure in the tire but it should be adequate pressure to get you home.
CO2 inflators come in two types. One type is just a nozzle that the cartridge screws into, and the other type comes with a handle into which the cartridge is inserted, and a nozzle.
The nozzle type takes only threaded cartridges. The CO2 cartridge is screwed onto the nozzle. You will hear a little bit of gas escape as the nozzle pierces the cartridge. This primes the nozzle. Then the other end of the nozzle is snugged down over the tube valve.
This CO2 inflator is just a nozzle. The cartridge is already threaded on. Now just press the little red button…!
Then to release the pressure into the tire, there is usually a button on the nozzle to press. Be careful to have gloves on because the CO2 cartridge will get pretty cold on releasing gas.
For the nozzle and handle type, the main difference is the CO2 cartridge need not be threaded because the cartridge is placed inside the handle. Then the nozzle is then screwed onto the handle and pierces the cartridge with a small amount of gas escaping. Now the nozzle is primed to release the gas into the tire. Just snug the unit onto the valve and press the release button. Whoosh! Your tire is inflated and ready to go!
cartridge goes in the handle, shown here with the nozzle already on.
Here is a handy YouTube clip that demonstrates how to use the Performance Quik Shot CO2 inflator:
http://www.youtube.com/watch?v=ItpqUSuy2nA
No worries about over inflating your tire or the cartridge exploding. Just make sure you get a cartridge for your tire size. For most road bikes e.g. 23cc tire, that would be a 16g cartridge. Ask at your local bike shop to be sure.
Important: when you get home from your ride, let the CO2 out of the tire that flatted and replace with atmospheric air. CO2 leaks from tires faster than normal air. The next day you might discover your tire is flat again. But it isn’t! It just leaked the CO2 out.
The big advantage of CO2 inflators is the quickness and ease of inflating a tire. The disadvantage is you can run out of cartridges on “one of those days”. Also occasionally an inflator nozzle fails to get adequate pressure into a tire. A frame pump might be necessary to top off the tire pressure.
My recommendation is be to bring a CO2 inflator and a frame pump, especially on longer rides. Neither are that heavy and are easily carried on the bike frame or saddle bag. Neither are terribly expensive either. Frame pumps can be had for $30-40. CO2 inflators can be as low as $15 or as pricey as $30. Make sure you try the CO2 inflator at home first or at your local bike shop first!
If you feel guilty at not working your biceps you can go work out at the gym after the ride, because hey! you saved all that energy not having to pump up your tire 😀
My Blog on Bike Tires/Tubes 