nitrogen in bike tires?

Discussion in 'Cycling Equipment' started by guitarbiker, Apr 21, 2006.

  1. guitarbiker

    guitarbiker New Member

    Joined:
    Apr 20, 2006
    Messages:
    9
    Likes Received:
    0
    I was wondering if anyone fills their bike tires with pure nitrogen. I just filled my car tires with it for better gas mileage due to less rolling resistance, less leakage, pressure not changing due to heat build-up and less corrosion on rims since nitrogen doesn't hold water vapour. The mechanic asked if I wanted my bike filled with the stuff and I said sure. I'm not sure of the results....I immediatly noticed that the bike didn't bounce when I dropped it from 6 inches or so it just sort of stuck to the ground. The ride seemed like I had more control on cornering and downhills seemed faster. I thing nitrogen is lighter than air we commonly use to fill tires with.
    So I was wondering if anyone else is doing this or is it old hat.
    Thanx
     
    Tags:


  2. dgregory57

    dgregory57 New Member

    Joined:
    Jul 11, 2005
    Messages:
    708
    Likes Received:
    0
    I have never done this, but with my limited scientific knowledge it makes little sense to go through this effort.

    The air we breath is about 78% Nitrogen, so if it is the best air to use, then you get an impure version at any gas station compressor.

    Nitrogen is roughly the same weight as the 78% mixture of Nitrogen we breath... If it were significantly lighter, it would tend to rise out into the outer layers of the atmosphere like helium and other light gases do.

    In a quick search, it looks like the real benefit is in car racing where it ensures that there is no moisture in the tire. Moisture leads to greater difference in pressure between a cold and hot tire... It is a method racers use to ensure that their tire pressure is consistent whether in a dry place like Arizona or a humid place like Florida...

    If you are looking for light weight and stable pressure, I would suggest helium... It is an inert gas, and it would have the benefit of being lighter, but then you would possibly lose pressure more easily as well.
     
  3. wilmar13

    wilmar13 New Member

    Joined:
    Nov 30, 2003
    Messages:
    1,551
    Likes Received:
    0
    Yeah and that is rotational weight! :D
    Hmmm never heard of this giving you the benefits of better gas mileage, etc. Maybe there is something to it, I am interested to see what others say...
     
  4. rule62

    rule62 New Member

    Joined:
    Aug 16, 2004
    Messages:
    622
    Likes Received:
    0
    ha

    ha ha

    HAHAHA

    HAHAHAHAHAHAHAHAHAHAHA




    err, sorry.
     
  5. wilmar13

    wilmar13 New Member

    Joined:
    Nov 30, 2003
    Messages:
    1,551
    Likes Received:
    0
    I just did a google search and read enough to decide this is BS (nitrogen in tires I mean). The advantage is that it doesn't leak through the tire as does air so that your pressure will stay where you set it longer... the economy savings comes from not having your tire pressure reduced over time. If you keep your tires to correct pressure you will see no advantages as far as I can tell my my extensive and exhaustive 5 minute research ;) .
     
  6. lwedge

    lwedge New Member

    Joined:
    Mar 3, 2004
    Messages:
    1,552
    Likes Received:
    2
    Hey Wilmar, haven't seen you around in a while.

    Nitrogen would be a great replacement for CO2. I remember the first time I used CO2 after fixing a flat, my tire was almost flat again the next day of maybe the day after ? I took the tube out and filled the tube with my track pump and couldn't find the leak and the tube stayed inflated. I talked to the guys at my LBS and they explained the CO2 molecules are smaller (leaks through pourus rubber) than the gas cocktail we breath and pump into our tires using conventional pumps.

    lw
     
  7. artmichalek

    artmichalek New Member

    Joined:
    Sep 15, 2004
    Messages:
    2,010
    Likes Received:
    0
    You sure he filled them up to the correct pressure? Most shop air systems run 100-120psi, but I wouldn't be surprised if their canned N2 was running considerably lower.
     
  8. artmichalek

    artmichalek New Member

    Joined:
    Sep 15, 2004
    Messages:
    2,010
    Likes Received:
    0
    It's not BS if you're too lazy to check the pressure in your car tires regularly.
     
  9. wilmar13

    wilmar13 New Member

    Joined:
    Nov 30, 2003
    Messages:
    1,551
    Likes Received:
    0
    Yeah I started riding my bike a lot more and got busy with work during a move back to the US.

    I have done the same thing... WTF I just fixed that tire yesterday!... oh CO2 gets out of the tube :eek:
     
  10. wilmar13

    wilmar13 New Member

    Joined:
    Nov 30, 2003
    Messages:
    1,551
    Likes Received:
    0
    Touché... I guess I meant the nitrogen doesn't improve your gas mileage as all the promotional sites I saw claimed: "10-20% increase in gas mileage by using nitrogen!" was claimed by all I saw... they don't state that figure is based on the difference between proper pressure and low pressure and is not attributable to the nitrogen in the tires.

    I guess related to cycling maybe there is some benefit to it, if you like to use latex tubes and can't bear to break out the floor pump before a ride.
     
  11. Insight Driver

    Insight Driver New Member

    Joined:
    Jun 26, 2003
    Messages:
    494
    Likes Received:
    1
    Only people who have a different point of view of reality. There is no clear advantage to using nitrogen. You attribute the difference in pressure in your tire to the fact that there was nitrogen in it. I suggest you try helium in your tires. You will get a bigger difference in feel then.
     
  12. alienator

    alienator Well-Known Member

    Joined:
    Jun 10, 2004
    Messages:
    12,596
    Likes Received:
    160
    Less rolling resistance? If you think that the changes in a tire/wheel's thermal circuit due to changing from air to nitrogen are so great that rolling resistance will change in any meaningful way.....well.......I've got this house at 1600 Pennsylvania Ave. that I'll sell ya.....

    Bike stuck to the ground? Wow. Maybe at that exact moment in time there was a huge transient in local space-time that caused the gravitational force to spike and then drop before you could feel it. It must've happened exactly when the tires hit the ground. Maybe a micro black hole passed by. Good that you noticed because all kinds of misinformed people, like scientists, engineers, etc., would tell you that there's didly difference in compressibility between gases as far as you can tell.

    Actually, once I get to the top of a climb, I purge the Helium (smallest gas particle, don't ya know) from my tires and refill with Uranium Hexafluoride (heavy) so I can rail on the descents.

    Zooooooooooommmmmmmmmmmmm!
     
  13. moo-jo

    moo-jo New Member

    Joined:
    Sep 8, 2004
    Messages:
    19
    Likes Received:
    0
    I guess that you're just lucky nitrogen isn't flammable, because all the flames in here would've caused trouble otherwise.
     
  14. guitarbiker

    guitarbiker New Member

    Joined:
    Apr 20, 2006
    Messages:
    9
    Likes Received:
    0
    WOW! A lot of scientists ride bikes! And very sceptical at that!

    If you read my original post I asked if anyone had tried the pure nitrogen in their bike tires. I gather from your responses that not one of you have. That's okay I'm known as somewhat of a trailblazer.
    After a week of riding both mountain and road bike on the nitrogen filled tires I've noticed a very small improvement on downhill rolls. I seem to coast past my friends.......I don't know why. Molecular weigh of air is 28.9 and nitrogen 28. If air is 79% nitrogen then there is a very small improvement in rotational weight.
    The other improvement I found was that I didn't need to top up tire pressure on the road bike like I usually had to do. I'm using very thin michelin latex tubes and I think that regular air can leak through them.
    Anyhow I don't find any disadvantage to using nitrogen except that I have to use a presto adaptor at the gas station.
    Please let me know if anyone tries this gas in their tires.

    Over
     
  15. alienator

    alienator Well-Known Member

    Joined:
    Jun 10, 2004
    Messages:
    12,596
    Likes Received:
    160
    Uh-huh. Sure you are.

    So what does an "air" molecule look like? And how were you able to calculate the molecular weight of air? The fact that you don't know why you coast past your friends speaks volumes about your analytical methods.

    Care to actually calculate the difference in rotational weight between a tire filled w/ air and one filled w/ nitrogen? I'm willing to bet you don't even have access to a scale that can resolve the difference in weight between an uninflated tire and an inflated tire.

    Let's see......I use Michelin Ultra lite tubes, and I top mine off every 3 or 4 days, using plain old generic air.

    Sooooo, how is it that nitrogen requires a "presto" adapter? Is that a magical adapter? Is that like a presta adapter?

    You should do some research into what scientific method is.
     
  16. ccrnnr9

    ccrnnr9 New Member

    Joined:
    May 5, 2004
    Messages:
    152
    Likes Received:
    0
    I fill my tires with helium...helps for hill climbing
     
Loading...
Loading...