Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

Nitrogen filled tyres

Discussion in 'Maintenance and Servicing' started by zx9er, Jul 4, 2015.

  1. Hello,
    I've just seen a dealer bike advertised as having nitrogen filled tyres?? Whats the advantage to using nitrogen in tyres???

  2. when you suck the air out your voice goes funny?

    umm sorry wrong tyre!
    • Funny Funny x 1
  3. nitrogen is in (almost) all tyres.

    it's not the nitrogen that is important, but what is not there. ie, oxygen and water.
    one idea is that not having oxygen inside your tyres means that when they get hot, the oxygen doesn't react with the tyre rubber.

    however all of the outside of the tyre is in contact with air = 21% oxygen anyway.. how often have you heard of tyres being burnt from the inside?

    another idea is that compressors often get a bit of water in their lines, so might spit a bit of water into the tyre as well.
    the liquid water, when heated, will vapourise and increase the tyre pressure.

    another idea yet again, is that "ocygen leaks faster from the tyre than nitrogen"

    but basically, it's just a gimmick. air is 79%(ish) nitrogen, and unless they fill and bleed and fill and bleed, maybe 10 or more times, you will still have a reasonable amount of oxygen in the tyre anyway.. certainly enough to react with the rubber.

    it's basically bullshit for road vehicles
    • Agree Agree x 6
    • Informative Informative x 2
  4. Nitrogen is "inert" so doesn't expand when warm or contract when cold therefore your tyre pressure stays optimum and stable whether you are riding at 0c or 40c. seems to work OK. Tyres are supposed to run cooler and wear better but Tassie kills tyres very quickly so can't comment on that.
    • Disagree Disagree x 4
    • Funny Funny x 1
  5. now for high demand applications... maybe dragsters, jumbos and space shuttle, where tyre temps can be REALLY high, there is benefit to excluding water.

    oh and the "doesn7t expand thing"... I only need to say one thing..

    PV=nRT :D
    pressure x volume is proportional to temperature.

    both nitrogen and oxygen behave as ideal gases for the purposes of expansion or contraction with temperature

    plenty of debunking info out there Nitrogen or Air?
    • Agree Agree x 3
    • Informative Informative x 2
  6. Nitrogen + oxide = Nitrous oxide

    Therefore my bike has NOS
    • Funny Funny x 3
  7. I haven't used it myself, but saw it at a Yamaha dealer. It is called Nitrotyre and is claimed to contain at least 96% nitrogen. It supposedly only loses 2 psi every 6 months. Pressure is also supposed to remain constant regardless of the temperature. Also claimed to increase tyre life. Costs $79 every 12 months. Not a gimmick as has been used by the military and civil aviation for years, but the benefits in a motorcycle tyre would be minimal.
  8. You are correct that Nitrogen is descibed as "Inert", but what his means is that it doesn't readily react with other chemicals/compounds...which is what the marketing machine is trying to cash in on.

    As oldcarrollas said...all gas will have different pressures at diferent temperatures.
    • Informative Informative x 1
  9. #9 oldcorollas, Jul 4, 2015
    Last edited: Jul 4, 2015
    Tires - Nitrogen air loss study

    ""Consumer Reports wanted to find out if nitrogen is worth the price, so we purchased a Nitrogen Inflation System and checked out how well the inflation held up over a one year period. We evaluated pairs of 31 tire models of H- and V-speed rated, all-season tires used in our tread wear test from 2006. We filled one tire per model with air and the other with nitrogen. The test was quite simple: fill and set the inflation pressure at room temperature to 30 psi (pounds per square inch); set the tire outdoors for one year; and then recheck the inflation pressure at room temperature after a one year period.

    The tires were filled and deflated three times with nitrogen to purge the air out of the tire cavity. We also used an oxygen analyzer to be sure we had 95-percent nitrogen purity in the tire--the claimed purity limit of our nitrogen system, which generates nitrogen gas from ambient air.

    The test started on September 20, 2006 and the final measurements were taken on September 20, 2007. The results show nitrogen does reduce pressure loss over time, but the reduction is only a 1.3 psi difference from air-filled tires. The average loss of air-filled tires was just 3.5 psi from the initial 30 pressure setting. Nitrogen-filled tires lost an average of 2.2 psi from the initial 30 psi setting. More important, all tires lost air pressure regardless of the inflation medium, so consumers should check their tires' air pressure routinely. No evaluation was done to assess the aging claim.""

    some difference yes. for completely static tyres etc etc.
    difference in real world for normal people? no.

    military and civil aviation use it because the nitrogen is DRY.
    much easier to guarantee dry gas from a bottle than from a compressor.
    plane tyres get hot when they skid on the runway during landing.
    any condensation in aircraft tyres will suddenly evaporate, leading to a sudden pressure increase right when tyres are loaded and heated.
    99% of the time this is probably fine, but a bit too much water, and a bit too much pressure increase, could lead to a blowout, which is not an acceptable risk for aircraft.

    also, aircraft = big tyres = lots of air lots of air loss (nitrogen loss) = lots of refilling = lots of chance to pump more moisture into the tyre = problem gets worse over time = bad for aviation safety record :D

    all the handling and safety etc benefits touted are due to properly inflated tyres... not nitrogen.

    so... what about CO2? that people use for emergency inflation? :) even bigger molecule than nitrogen = less gas loss, what about Argon? it's actually "inert"

    why don't they use Argon instead of Nitrogen in space shuttle tyres? because it pretty much wouldn't make any difference what dry gas they used (sure there are some which are not good)

    knew I forgot something... aircraft, moisture freezing in bottom of tyre at altitude = tyre balance problems when landing
    Filling tyres with nitrogen | AA
    • Agree Agree x 2
    • Like Like x 1
  10. Well I totally endorse the Nitrogen thing, but only use 78%. I find the mix ( with 21% oxygen .03% Carbon Dioxide and a few rare gases for flavour) works just fine and is really available cheaply.

    Tyre gauges are a bigger problem.

    Sounds like Consumer reports has found someone with too much time on their hands. The bit about aircraft and moisture is interesting. By the way, you CAN buy dry compressed air from BOC.
    • Winner Winner x 2
    • Agree Agree x 1
    • Funny Funny x 1
  11. any idea how much for a bottle? I use 99.99% and 99.999% N2 bottles for work.. but the 5x 9's is a bit too expensive for using in tyres :D (few hundred per bottle?)
    if you were REALLY worried about tyres, you'd get 6x 9's purity at a couple grand per bottle :D
    • Informative Informative x 1
  12. Yep, the Nitrogen myth. In real world, it makes bugger all difference, and not worth the hassle. Save it for the shocks.


    "Tyre gauges are a bigger problem." I agree with that. I can never find two that agree with each other.
    • Agree Agree x 1
  13. oldcorollas,

    I could chase the invoice, but honestly it would be a whole lot easier just to ring the depot and get a quote. We've got an E size bottle and I THINK it was $135 or so. For what we use, the bottle hire costs more, but ya gotta have what ya gotta have, and they do squeeze a lot of air into them.
    • Informative Informative x 1
  14. I should do that Monday :) be interesting to see how many tyres can be filled for what cost (although tyre places would be using a nitrogen generator?)
    I hate paying for my MIG bottle rental :( can't bring myself to buy one and tie myself to a particular company and gas mix
  15. Perhaps tyres should be filled with Helium.Less unsprung weight = better handling.
    • Agree Agree x 1
  16. #16 oldcorollas, Jul 5, 2015
    Last edited: Jul 5, 2015
    this is an interesting read (if you are a science history buff) :) I'm sure there is more recent and much more accurate data but interesting how they measured this sort of stuff back then.. https://ia800304.us.archive.org/28/items/permeabilityofru00edwa/permeabilityofru00edwa_bw.pdf
    (and of course completely different rubber these days)

    1920's, US Bureau of Standards, looking at permeability of different gases through thin rubber backed material used for airships and balloons. page 347 onwards I think?

    Oxygen, around 4.5-5L per m^2 per 24hrs
    Nitrogen, around 1.5L per m^2 per 24hrs (3 times slower)
    Argon, about 1.6 times faster then N2
    CO2 around 20 times faster than nitrogen
    Helium a bit faster than oxygen

    one interesting bit was how rubber can be used to concentrate oxygen..


    one thing you can calculate from the permeabilities, is that pure nitrogen will leak only 30% slower than air.. (where both nitrogen and oxygen leak)
    That means that pure nitrogen leaks at 70% of the rate of air, ie if you lose 3psi air, you'd lose roughly 2psi nitrogen anyway

    interestingly the rate of air leakage will slow down over time, as the oxygen levels inside the tyre go down..
    if you keep topping up the tyre, it becomes a nitrogen accumulator! note this is for diffusion of gas through the rubber, not from mechanical leaks, but a similar process may occur there

    found a decent table showing size of various gases (kinetic diameter being the relative size when considering dynamic process like diffusion)
    size alone is not the only important thing.. the effective pore size relative to the permeant is what is important.. and how you can use membranes to delectively filter out different gases

    ok, I'm nerded out now :D

    ok.. one more..
    • Informative Informative x 2
  17. Guess I got suckered into paying $7.00 a tyre for no benefit ........ Although if they use it on the "shuttle" tyres for landing it might help me coming out of our potholes.
  18. This is the biggest con going around. You won't notice any difference at all!
    • Agree Agree x 2
  19. Bob Jane and bridgestone tyre stores have been offering this for years!
  20. Actually he was wrong on both counts. Nitrogen is not one of the inert gasses. It does react with other chemicals (NO2&3 for example).

    And even if it were an inert gas, that does not mean it doesn't respond to the universal gas laws.

    Oh and Nitrogen filled tyres = bullshit.