Stayfill® keeps your wheels ready to roll


Stayfill® makes a good idea better

We’ll be the first to admit that those little CO2 cartridges used to fill up bicycle tires are a darn good idea. But like all good ideas, they eventually evolve into even better ideas. If you ever used CO2 for your bike, you probably found out the hard way that CO2 simply does not stay in your tire very long. In fact, CO2 begins leaking through the tire wall almost immediately after inflation. We found that most tires filled with CO2 last about 2 weeks before they are down to almost empty.

How about air? Air also leaks through the tire wall, but not as rapidly as CO2. That’s why tires filled with air take a bit longer to lose pressure. But they lose pressure all the same. Unfortunately, because air doesn’t compress like CO2, you can’t put a lot of volume into one of those little metal cartridges.

Stayfill® lasts 100 times longer than CO2

We did multiple head-to-head tests with tires filled with Stayfill®, CO2 and air. It wasn’t even close. Now granted, you may find slightly different leak results for tires filled with CO2 or air depending on the tire manufacturer, tire size and model, and whether the tire is of the tube or tubeless variety. One thing you won’t find different is Stayfill’s performance. If you extend the timeline out a year or more, a tire filled with Stayfill® still retains its original fill pressure.

Tire leak rates


Stayfill® cannot leak out

Now for the evolution: Stayfill® can’t pass through the wall of the tire. We have tires in our lab that were filled 4 years ago and they still retain the same pressure today as the day they were filled. Because of Stayfill’s large molecular size, it cannot leak out. (Note: Recall from your science classes that pressure is also a function of temperature, so if you “check it out”, tire pressure will vary depending on the ambient temperature. Heat will increase pressure and cold will decrease it.)

CO2 molecules vs. Stayfill molecules


Stayfill® is a drop in replacement for CO2

We designed Stayfill® so that it could be used with standard CO2 threaded cartridge dispensing valves. We’ve been asked if there is any problem mixing CO2 and Stayfill® together. The only problem is that the CO2 left in the tire will still leak out and this will require some topping off with more Stayfill®.

Tire types and cartridges


Note: These are estimates and actual results may vary with different tire manufacturers, fill method, and temperature. An optimum Stayfill® fill would include 10 psig of air in addition to Stayfill®.

Stayfill® Product Line

Our initial package for Stayfill® was a 25 gram cartridge which was the same size as the standard 16 gram CO2 cartridge offered for sale. What we found is that customers hated having to use multiple cartridges and to fill bigger tires and the economics were not the best. We heard you and we responded. Stayfill® is now packaged in a 115 gram cartridge. This larger cartridge provides enough gas to fill two standard 26” mountain bike tires to 40 psig and will handle three high pressure road tires.

We have a starter pack which includes a dispensing valve. And for you with the dispensing valves, you can buy the cartridges individually or in a four or ten packs.

We have found that this larger size will also give you a partial fill on motorcycle tires and will fill a lot of soccer balls.

Stayfill® has other uses, too

If you’re always pumping up basketballs, soccer balls, or footballs, use Stayfill® instead. The hardest part will be remembering where you put that little needle. You can even use Stayfill® for inflatable pool toys and mattresses. Lastly, use Stayfill® on the tires of those baby joggers, which are constantly going flat, and never worry about filling them again. Nothing’s more depressing than seeing a baby with a flat tire.

We invite you to try Stayfill®!