Every once in awhile I see someone ask a question about the effectiveness of Co2 cartridges for motorcycle tire inflators. A member of another thread was asking about
BikeMaster’s Tire and Tube Flat Repair Kit. It seems that repair kits with Co2 inflators are becoming more popular. I think that’s good from the standpoint that people have more options to deal with a flat in an emergency.
However, as I got looking into it a little more, I was a little set back by some of the claims being made by the retailers. While BikeMaster actually didn’t make any claim about how many cartridges did what, popular retailers
Pit Possee Motorsports said that each of three tubes in their kit fills an average front or rear motorcycle tire and
Rocky Mountain ATV/MC/Tusk that only sold two tubes and an inflator, said that 1-1 ½ tubes would fill a motorcycle tire and 2 tubes would fill an ATV tire. I seriously doubted those claims.
I’m very familiar with Co2 cartridges and inflators because my family operates a bicycle repair and accessories business. We sell them (Planet Bike Air Kiss line) and we use them on our biking activities. Co2 inflators are becoming almost the standard in emergency bicycle tire repair. They don’t take up much room, they’re light and they’re fast.
They come in three popular sizes in terms of volume of air: 12g, 16g and 25g, where “g” refers to grams. For purposes of our bicycling business, we know from experience that the 12g will fill a small mountain bike tire, the 16g will fill a medium sized mountain bike tire and a 25g will fill a road tire, 700c or large 29r mountain bike tire. In some instances, such as in the case of a high pressure 700c, they’ll only inflate to a “usefulness” level that’ll hopefully get you someplace to fill to the proper pressure.
Now the question is what’s needed to fill a motorcycle tire?
I decided to waste 4 of our 16g cartridges (emulating the 4 cartridge BikeMaster Kit) and on the rear tire of the Versys 1000 (tubeless, 180/55-17, 42 psi):
We like the Air Kiss because it’s a good quality product. Once locked on the valve stem it stays there. Also, the Air Kiss has a cartridge cover that’s important (BikeMasters doesn’t have the cover). When the air discharges from the cartridge it becomes super cold. Some have said it gets cold enough to burn skin. I’m not putting that to the test. The way it works is once locked on the valve stem, the inflator barrel is slid backward along a track and held there to discharge the air. There’s a big woosh and the rest streams out over 8-10 seconds.
The first cartridge was quite a bit short of filling the tire
The second cartridge showed a one-pound improvement over the first.
The third and fourth cartridges were consistent with the first two. Note that the cartridges get all frosty.
So, the average psi per 16g cartridge was 5.5 psi and all four pumped the tire up to 22 psi. This is actually better than I expected.
Applying a little math to the information obtained, filling the tire to its 42 psi spec would require 8-16g cartridges, 10-12g cartridges or 5-25g cartridges. And this would seem to prove out my suspicions that Pit Posse’s and Rocky Mountain’s claims are totally exaggerated.
Your conclusions about whether Co2 cartridges are a good idea or not would be interesting to hear. There are certainly pros and cons. However, as part of an emergency kit with no less than 4 cartridges, I think it may be all one needs to get to the filling station after a flat repair and get a tire filled properly. However, I think I’ll continue to carry my Slime Powersport Air Compressor.
