Different gases for tires

Forums Mountain Bike Forum Different gases for tires

Tagged: ,

Viewing 6 reply threads
  • Author
    Posts
    • #234584

      What’s up riders,

       

      Anyone know if a lighter gas could be used instead of air? Helium, argon, even nitro? How is the feel, is there any noticable difference?

       

    • #234585

      Different gases have varying molecular size, so using gas such as helium will be a poor choice because it is the second smallest atom known and will pass through the tire and sealant much easier than air.  It’s fun to inhale it and listen to goofy sounds your voice makes though.

    • #234587

      Have you weighed your wheels before and after filling with air?  I don’t think you’d be able to detect a difference. I also don’t think you’d be able to measure much of a difference even with something lighter than air like helium, since you’d be compressing it into a more dense format than what’s in a helium balloon for example.

      I know there are a lot of cars out there with nitrogen in the tires, but that’s a bit of a scam (I can run through the math for anyone interested).  I like to use a mixture of 78% nitrogen, 21% oxygen and various other gases.  It’s readily available EVERYWHERE.

    • #234600

      I would use hydrogen, lighter than helium and probably ideal for fatbike tires. Very safe unless exposed to any sort of spark.

       

      Ivan

    • #234606

      Interesting question.  I’ve never thought about it, for bikes, anyway.  I have used nitrogen in my car and truck tires.  My personal experience has been less pressure loss over time, especially in colder months on large (high air volume) truck tires.  And significantly more stable pressure driving hard in hot weather with low profile, low volume, tires, probably due to the fact there is less expandable water vapor in nitrogen (my unscientific guess).

      But… who cares about cars!  What about mountain biking?!?!  No realistic weight advantage that I could imagine.  The reality is, when air is compressed (by a compressor), it is “dried” to some extent, and winds up being something like 80% nitrogen already.  My observation has been that when I fill a tire (100%) with a hand pump versus my compressor, I actually do notice that the compressor filled tire goes much longer before I need to add air to maintain pressure.  I realized this once when I had fill a flat using a hand pump, and then thought it was leaking because I would need to add air before every ride, while my other compressor filled tire went on may rides without loosing pressure.  Once I refilled filled the hand pumped tire with the compressor, it too went longer without pressure loss.

      So yeah, there’s advantage for pressure loss using nitrogen, but is it worth the extra effort (trip to a shop that has pure nitrogen), or is it easier to just use a compressor at home, giving you pretty close to 80% nitrogen?

      • #234646

        Regular old household air is 78% nitrogen, 21% oxygen and 1% other stuff.  A compressor will remove some of the moisture in the air via condensation, but doesn’t change the amount of nitrogen or oxygen.

        If you believe that nitrogen is better for pressure loss, I suggest filling with air.  When the pressure drops over time, this theoretically should be mostly the oxygen that is leaking out.  At this point your pressure will be low but the gas inside will be almost 100% nitrogen.  When you refill again with air, you’re replacing the lost oxygen with 78% nitrogen again.

        Every time you refill with air, the nitrogen content inside the tire gets higher and higher IF the oxygen is preferentially leaking out.  If you don’t believe any of this, keep paying for nitrogen (the most abundant gas on our planet).  Air has NEVER let me down.  Wait…that sounds like a song.

    • #234607

      Some mountain bike racers (particularly DH riders) do use nitrogen for the reasons that have been mentioned. At various times companies have tried to market nitrogen products to mountain bikers, but none have really taken off. Co2 is a pretty common substitute for regular old pumped air, but I don’t know that it makes any difference (though I have heard some riders claim it “leaks” faster than air.)

    • #234652

      I run pure nitrogen sometimes out of laziness. My little nitrogen bottle doesn’t need to be pumped and is silent. I makes less then zero difference on the trail or otherwise. All tires/tubes leak over time, regardless of the size of your molecules

Viewing 6 reply threads

You must be logged in to reply to this topic.