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  1. #1
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    Nitrogen in bike tires?

    I just finished converting my new Carve SL to tubeless. It was actually a really easy swap as the bike came with new presta valves and the wheels were taped already! I was just thinking would there be any advantage to N2 vs Air with a tubeless setup? N2 molecules are larger, but it may not make a difference at all lol.

    I have access to N2 at work so I may just try it out, Im bored on nightshift and may just be over thinking a problem that doesn't really exists haha.

    Jake

  2. #2
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    Nitrogen in bike tires?

    Like car tyres, they stay in longer without escape but tbh I never found any so-called benefits. Good luck

  3. #3
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    Pure nitrogen versus pure oxygen, the molecule really isnt that much larger. Its kind of irrelevantly larger.

    But thats pure oxygen, our air is something like 75% nitrogen so comparing atmospheric air molecules to pure nitrogen, theres very very little difference.

    Its really a total waste of time, atmospheric air is as good as it gets for a bicycle.

  4. #4
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    Hasn't this been covered a few times already?

  5. #5
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    So lets cover it again. It is actually rather common to fill tires with nitrogen. Oxygen is reactive so it does some damage to the tires. The biggest advantage though is canned air has no water so there is less pressure increase in the tire at 212 degrees. This does happen on a long brake.
    "Dish is illogical." Spoke of Vulcan.

  6. #6
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    Nitrogen in bike tires?

    Quote Originally Posted by zerodish View Post
    So lets cover it again. It is actually rather common to fill tires with nitrogen. Oxygen is reactive so it does some damage to the tires. The biggest advantage though is canned air has no water so there is less pressure increase in the tire at 212 degrees. This does happen on a long brake.
    Disc brakes = no braking heat build up in the rims/tires.

    You still need to purge the air from the tire before filling with nitrogen. And if you are using a sealant there is always going to be moisture inside.
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    At least no one has mentioned helium !
    /sarcasm

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    Nitrogen in bike tires?

    Well shoot, I have access to lots of hydrogen at work! Hmm...combustable tires? Maybe Red Bull will sponsor me.


    Nitrogen was/is very useful for this little machine where dynamic temps easily pass the 200F mark

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    The pressures would still increase almost as much as with air, but it was much more consistent and predictable (assuming all the air and moisture had been effectively purged). Definitely helps to have more stable tire pressures when the sweet spot is only a couple psi range. Sucks going out on cold tires!

    Anyone know of WC DH teams that have talked about testing/using Nitrogen? Those tires see an immense amount of stress and no doubt generate some serious heat. But how much?

    Anyway, as far as bikes and Nitrogen; forks and shocks operate at relatively high pressures and temperatures so will benefit from a more stable gas. That's where we would feel a difference if more than just-riding-along (it's all relative, I know).

  9. #9
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    Nitrogen in bike tires?

    Quote Originally Posted by conekilr View Post
    Well shoot, I have access to lots of hydrogen at work! Hmm...combustable tires? Maybe Red Bull will sponsor me.


    Nitrogen was/is very useful for this little machine where dynamic temps easily pass the 200F mark

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    The pressures would still increase almost as much as with air, but it was much more consistent and predictable (assuming all the air and moisture had been effectively purged). Definitely helps to have more stable tire pressures when the sweet spot is only a couple psi range. Sucks going out on cold tires!

    Anyone know of WC DH teams that have talked about testing/using Nitrogen? Those tires see an immense amount of stress and no doubt generate some serious heat. But how much?

    Anyway, as far as bikes and Nitrogen; forks and shocks operate at relatively high pressures and temperatures so will benefit from a more stable gas. That's where we would feel a difference if more than just-riding-along (it's all relative, I know).
    A WC DH run is under 3 minutes in most cases.

    For mtb tires, heat buildup is a total non-issue. Not from braking. Not from casing/tread flex.

    Unlike motorsports, cold tires mean little on the trail. Bicycle tires are designed for use at ambient temperature and the tire temp does not change significantly in use.
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    Regarding pressure, when my tire is filled to 25 PSI , by the 45 min point it's at 28 to 29. As for nitrogen in mountain bike tires, filling them with 100% N2 Vs. 80% N2 (air) is a complete waste of time.
    Last edited by MSU Alum; 07-01-2013 at 02:28 AM.

  11. #11
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    Nitrogen in your air sprung suspension would be more beneficial.

  12. #12
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    Quote Originally Posted by bikeabuser View Post
    At least no one has mentioned helium !
    /sarcasm
    Dude, go big, go hydrogen!!!!!!!!!!!!!!!!!!!!

    I use it in the air cart on my Lefty. Around this time of yr my lefty doubles as my front suspension and a fireworks show. I just loosen the valve to get some flow and lite it. It's a great 30 sec show.............
    Lead by my Lefty............... right down the trail, no brakes.

  13. #13
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    Quote Originally Posted by customfab View Post
    Nitrogen in your air sprung suspension would be more beneficial.
    That's why Fox uses it
    Lead by my Lefty............... right down the trail, no brakes.

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    Quote Originally Posted by ziscwg View Post
    That's why Fox uses it
    My Fox came with a pump that puts ambient air in the fork.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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    Quote Originally Posted by meltingfeather View Post
    My Fox came with a pump that puts ambient air in the fork.
    Love it!

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    Quote Originally Posted by meltingfeather View Post
    My Fox came with a pump that puts ambient air in the fork.
    The RP23 and I think some forks have a nitrogen charged internal chamber in addition to the ambient air chamber you "dial in" with a shock pump.
    Lead by my Lefty............... right down the trail, no brakes.

  17. #17
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    Nitrogen in bike tires?

    Quote Originally Posted by ziscwg View Post
    The RP23 and I think some forks have a nitrogen charged internal chamber in addition to the ambient air chamber you "dial in" with a shock pump.
    Yes, many shocks do that. Not aware of a fork that does.
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  18. #18
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    Helium is used in olympic races it saves a few grams. Hydrogen will form acids and kill your tire.
    "Dish is illogical." Spoke of Vulcan.

  19. #19
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    Quote Originally Posted by shiggy View Post
    Yes, many shocks do that. Not aware of a fork that does.
    I thought some of the Fox forks did. My buddies fork blew a seal at Downiville and I remember the guys at the shop there ripping it apart and saying something about a nitrogen cartridge or something. I could have misunderstood.
    Lead by my Lefty............... right down the trail, no brakes.

  20. #20
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    Quote Originally Posted by meltingfeather View Post
    My Fox came with a pump that puts ambient air in the fork.
    My pump puts a proprietary mix of nitrogen, oxygen, and a small amount of other inert gasses, just for safety.

    Gotta pay extra to get the good pump!

    Nearly all piggyback shocks, for HD use, use air, not nitrogen... something to think about. RS lets users service their shocks and sets them up to just pump air back into the IFP chamber. I dont think pure nitrogen has much legitimate use on bikes at all.

  21. #21
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    Quote Originally Posted by zerodish View Post
    Helium is used in olympic races it saves a few grams. Hydrogen will form acids and kill your tire.
    myth/misinfomation alert.
    Helium is not regularly or currently used in olympic bicycle races. It is not used in any bicycle races that I know of.


    FWIW there is about 12g of air in a typical 29er mtb tire and Helium weighs about 1/7 what air does.
    Quote Originally Posted by pvd
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  22. #22
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    I see no benefit to nitrogen other than to avoid oxidation of rubber. As far as being a stable gas, I don't see how it can be any more stable than air. Air can be dried to the same level as nitrogen, and air and nitrogen will behave identically in terms of their pressure vs. temperature behavior at normal tire conditions.

    I think some big trucking fleets use nitrogen to help the tire casing last longer. Truck tires can be recapped, and the casing can sometimes be used for a million miles (IIRC). Using nitrogen will result in less oxidation of the rubber so that it will last longer.

    I imagine nitrogen charged shocks also use nitrogen instead of air to avoid oxidation of rubber seals.

  23. #23
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    Re: Nitrogen in bike tires?

    I use krypton, specifically krypton 86. Very stable. Inert actually. 8 valence electrons. So, yeah, you've got that going. 50 neutrons too. Sure its expensive, but, better than that argon or neon you get on those dept store bikes. Those have like 20 neutrons max, depending on the isotope.

    But if you really wanna go all out: xenon. Its the latest thing. Very pricey. But, its the best you can put in your tires.
    Last edited by Procter; 07-03-2013 at 10:45 PM.

  24. #24
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    Quote Originally Posted by shiggy View Post
    Yes, many shocks do that. Not aware of a fork that does.
    Specialized Future Shock forks (with all the internals in only the right fork leg) use nitrogen I believe. Possibly some of their other in house designs.

  25. #25
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    Using Nitrogen in anything other than race tires seeing high temps is probably the biggest scam at car dealers right now, un****inridiculous.

    I worked with a pro BMW race team for several years, and some of that time I was the tire temps/pressure guy that monitored and analyzed tires during sessions as an indicator to making adjustments to the suspension set-up on the car.

    Nitrogen is only used in race car tires as it doesn't get water build up and is more stable, thereby giving more consistent readings of tire performance.

    And the biggest reason its a scam at dealers, other than the lack of ANY benefits to street cars, is that they likely don't do the correct procedure for replacing air with Nitrogen in the tires. This is what we did with race tires....

    -pick up the new tires installed on the spare rims, it was a spec tire series and they arrived with air in them
    -remove the valve stem core and let the air bleed out, take about 20 seconds
    -with the valve core out hit it with Nitrogen for about 10 seconds
    -let it bleed until almost out, then hit it again for 10 seconds
    -repeat this procedure 2 more times, its getting the air out and replacing as much as possible with Nitrogen
    -as the last hit of Nitrogen its bleeding down you screw the core back in the stem, never letting all the Nitrogen to bleed out
    -fill with Nitrogen to 32 psf and monitor for leaking

    Do you really think the lowest paid guy in the dealer shop does this?
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  26. #26
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    Quote Originally Posted by shiggy View Post
    A WC DH run is under 3 minutes in most cases.

    For mtb tires, heat buildup is a total non-issue. Not from braking. Not from casing/tread flex.

    Unlike motorsports, cold tires mean little on the trail. Bicycle tires are designed for use at ambient temperature and the tire temp does not change significantly in use.
    However, convenience will favor Nitrogen in that you won't have to fill as much. Also, since much less 'moisture' less corrosive. Lastly, the moisture does expand/ contract. So if you ride one day in say 60 degree weather, another day in 80 degree weather, you will have different pressures due to ^ in temps.

    Using Nitro shaved off 5 seconds on my lap times...I went from 25th, to 24th!

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    Quote Originally Posted by madsedan View Post
    Using Nitrogen in anything other than race tires seeing high temps is probably the biggest scam at car dealers right now, un****inridiculous.

    I worked with a pro BMW race team for several years, and some of that time I was the tire temps/pressure guy that monitored and analyzed tires during sessions as an indicator to making adjustments to the suspension set-up on the car.

    Nitrogen is only used in race car tires as it doesn't get water build up and is more stable, thereby giving more consistent readings of tire performance.

    And the biggest reason its a scam at dealers, other than the lack of ANY benefits to street cars, is that they likely don't do the correct procedure for replacing air with Nitrogen in the tires. This is what we did with race tires....

    -pick up the new tires installed on the spare rims, it was a spec tire series and they arrived with air in them
    -remove the valve stem core and let the air bleed out, take about 20 seconds
    -with the valve core out hit it with Nitrogen for about 10 seconds
    -let it bleed until almost out, then hit it again for 10 seconds
    -repeat this procedure 2 more times, its getting the air out and replacing as much as possible with Nitrogen
    -as the last hit of Nitrogen its bleeding down you screw the core back in the stem, never letting all the Nitrogen to bleed out
    -fill with Nitrogen to 32 psf and monitor for leaking

    Do you really think the lowest paid guy in the dealer shop does this?
    I have a PMS in my car. Major difference between 'air' and nitrogen is the expansion. 15%-20% expansion observed on my PMS from Air to "N". Tire matrix less taxed w Ntiro due to above. Reduced 'moisture' is a big benefit/reason for lack of expansion. Which is also good to have less moisture on rims, rubber in long run. Not sure how much I'd be willing to pay for the benefits...but they do work...I get it for free, so it is a no brainer...I'm big into no brainers...er

  28. #28
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    Quote Originally Posted by everything motorcycl View Post
    However, convenience will favor Nitrogen in that you won't have to fill as much. Also, since much less 'moisture' less corrosive. Lastly, the moisture does expand/ contract. So if you ride one day in say 60 degree weather, another day in 80 degree weather, you will have different pressures due to ^ in temps.

    Using Nitro shaved off 5 seconds on my lap times...I went from 25th, to 24th!
    this "argument" is weaker than watery dogsh|t.

    do you use tin foil "vortex generators" in your car's air intake to get you 80 mpg ?
    Quote Originally Posted by pvd
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  29. #29
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    At 40 degrees C, air can hold 50g water per kg air. This would be like 100% humidity in the rainforest in the summer.

    At zero degrees C, air can hold about 4g water per kg air.

    So if you filled up your tires in the rain forest and then took a ride outside my house right now (freezing temps in Colorado on this February day), you would condense about 46 g water per kg of air.

    A tire has about .02 kg of air, (20g), so that would mean you condense about 1 gram of water.

    That's about 5% of the vapor contents by mass, or 8% molar.

    So even in this unrealistic example, 8% is the pressure loss, 15 to 20 % pressure loss caused by moisture, "expansion" as you call it, looks impossible in any practical scenario.

    That was fun, wasn't it?

    But if moisture content was a concern, all you would need is an air compressor with an air dryer on it, not nitrogen.

  30. #30
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    Quote Originally Posted by smilinsteve View Post
    So if you filled up your tires in the rain forest...
    You can get that effect at some of those quarter-feed compressors at the gas station... I've run into some that literally put out liquid water with the air.

    In the end that's what you need to be careful of (at least in a big car tire). Dry air or N2 is the key.
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    Quote Originally Posted by J_Westy View Post
    In the end that's what you need to be careful of (at least in a big car tire). Dry air or N2 is the key.
    Isn't this a bike forum?
    In four years and 50k(+) miles I haven't put air into my 33x12.50 truck tires once. How careful do I need to be?
    N2 is not the key to anything. All the "arguments" put forth in support of it are complete crap.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  32. #32
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    Quote Originally Posted by everything motorcycl View Post
    Lastly, the moisture does expand/ contract. So if you ride one day in say 60 degree weather, another day in 80 degree weather, you will have different pressures due to ^ in temps.
    Of course you will, that's what the ideal gas law says. It has nothing to do with moisture, however. It would also be less than a just-noticeable difference. Irrelevant.

  33. #33
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    Nitrogen is only beneficial if, and only if, it was administered by use of a Kunooter valve.
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  34. #34
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    Quote Originally Posted by meltingfeather View Post
    Isn't this a bike forum?
    In four years and 50k(+) miles I haven't put air into my 33x12.50 truck tires once. How careful do I need to be?
    N2 is not the key to anything. All the "arguments" put forth in support of it are complete crap.
    Not sure what your saying, but I'm saying the key is to not put water in your tires.
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    Nitrogen in bike tires?

    Quote Originally Posted by J_Westy View Post
    Not sure what your saying, but I'm saying the key is to not put water in your tires.
    My tires are full of sealant... Which is about half water.
    I should definitely focus on putting dry nitrogen in there, right?
    Or are we talking about race cars?
    My point about my truck is that I haven't had to put ANY air in my tires in 4 years... so I don't really have to think about it or be careful... and if I had put some water in my tires it's actually not a very big deal.
    The moisture argument for nitrogen is, like all the other arguments, complete crap.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  36. #36
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    I ran a modified sportscar on the track with about 2 cups of water in one tire. Ran again dry. lap times were similar. Nitrogen is a total scam for street cars. It's cconvenient race car teams who monitor temps to make changes. Dry tanks are easier than wet ccompressors, so even then the nitrogen itself isn't the benefit. Even at that level its not a huge difference.

    I worked at a dealer who tried to sell it. I refused to do the service, its really a scam.

  37. #37
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    Nitrogen is a scam for street vehicles, no shortage of shops willing to sell it and huge markup.

    Tires on commercial aircraft use nitrogen for good reason.


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    Quote Originally Posted by One Pivot View Post
    I ran a modified sportscar on the track with about 2 cups of water in one tire. Ran again dry. lap times were similar. Nitrogen is a total scam for street cars.
    And what were your tire pressures afterwards?

    Listen, All I'm saying is that water in your tires it's directionally wrong. Liquid water ensures the relative humidity in your tire will always be 100% meaning more of the water will turn to vapor (gas) the warmer it gets -- i.e. the old "n" in P = nRT/V -- so pressure will go up with temperature not only due to the "T" but also due to the "n" in the ideal gas equation.

    In a bike tire that we probably only fill up before each ride anyway and that doesn't warm up from rolling very much, it's not significant.

    For the average joe that only checks their tire pressure when the idiot TPS light comes on... well he doesn't care anyway.

    For someone that adjusts the pressure often with the seasons and cares about tire wear and handling, it makes some small difference.

    I'm not promoting N2 to either, just no water

    and to avoid quarter feed compressors at the gas station.
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    Quote Originally Posted by J_Westy View Post
    For someone that adjusts the pressure often with the seasons and cares about tire wear and handling, it makes some small difference.
    It make some "small difference" always, you aren't saying anything. It's important to know when "small differences" matter and when they don't.

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    Quote Originally Posted by meltingfeather View Post
    this "argument" is weaker than watery dogsh|t.

    do you use tin foil "vortex generators" in your car's air intake to get you 80 mpg ?
    I've made clear specific reasons why it works. You simply made some lame analogy and a few curse words. Case closed. You can also argue with all the large tire mfg who agree to the benefits of Nitro. You may be a broke ass that doesn't want to pay for it...to which I can understand if one doesn't want to pony up for it.

    But the science exists, unlike your little pea brain argument.

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    Quote Originally Posted by craigsj View Post
    It make some "small difference" always, you aren't saying anything. It's important to know when "small differences" matter and when they don't.
    We can all make opinions, draw conclusions. For me, the science is there on the benefits of Nitrogen. Is it worth it to pay for it? That is a personal opinion. I don't pay for it, so yes. 100% that it doesn't have the 'moisture'. There is little to no expansion or delta pressure. Much less loss in escape/diffusion through rubber matrix and bead.

    What is all that worth to you? That is subjective. But for all the haters saying it is doesn't work, they are defying science. It may not be to a significant amounts for one to pay. I'm not arguing that point. I'm on the side of science.

  42. #42
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    Quote Originally Posted by everything motorcycl View Post
    For me, the science is there on the benefits of Nitrogen.
    That's the thing... science is not subjective. It is not there "for you." A scientific (objective) look at nitrogen for use in tires shows easily that it is BUNK. You don't even have your facts right... moisture is what expands?
    Quote Originally Posted by everything motorcycl View Post
    Is it worth it to pay for it? That is a personal opinion. I don't pay for it, so yes. 100% that it doesn't have the 'moisture'. There is little to no expansion or delta pressure. Much less loss in escape/diffusion through rubber matrix and bead.
    All horse****. Nitrogen expands and contracts with temperature just like any other gas. You know air is 70% nitrogen, right? The "much" lower escape/diffusion is crap too. There may be some minuscule difference between 70% nitrogen (air) and 99% nitrogen, but playing it up as if you're going to stop having to put air in your tires all the time is complete BS. You think people believe this crap? People that have air in their car tires and NEVER have to add any?
    You bought somebody's sales pitch and use it because it's no cost to you and now are slinging it as if the science supports it when you don't have a single fact straight.

    Quote Originally Posted by everything motorcycl View Post
    I'm on the side of bunk hype.
    FIFY
    Educate yourself, dood. You are ignorant of the facts here.
    Quote Originally Posted by pvd
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  43. #43
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    Quote Originally Posted by J_Westy View Post
    And what were your tire pressures afterwards?
    Heres the real kicker... they were higher both times. The tire compound would turn to grease and Id start sliding around waaaaaaay before the pressure change impacted balls out performance driving on the track. The tires could never heat up enough for the moisture content to actually matter, since the compound was overheated way before that happened.

    You need track tires for it to make a difference. You need to be racing an event where you're out there long enough for it to make a difference.

    but who cares, this is a bike forum. We fill our tires with water/sealant as-is, and we call it a performance increase.
    Listen, All I'm saying is that water in your tires it's directionally wrong. Liquid water ensures the relative humidity in your tire will always be 100% meaning more of the water will turn to vapor (gas) the warmer it gets -- i.e. the old "n" in P = nRT/V -- so pressure will go up with temperature not only due to the "T" but also due to the "n" in the ideal gas equation.
    Yes, temperature rises. Pressure rises. It doesnt matter, thats the thing. The conditions where it does matter are pretty extreme, and even car enthusiasts at the track are unlikely to hit those conditions.

    You need a real race car, a suspension engineer, a support team and a set of fresh track tires for it to matter.

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    More fun regarding this topic. At the last place I worked, I went to go investigate the "nitrogen" machine.

    It was a huge box connected to our shop air with a water trap on it. It was really big and looked like it might store compressed gas, but it didnt. It was a water trap with a digital filter, and we'd charge people $40 to fill their tires with it and put those green caps on. This is a very common nitrogen setup. Its a flat out scam.

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    Quote Originally Posted by meltingfeather View Post
    That's the thing... science is not subjective. It is not there "for you." A scientific (objective) look at nitrogen for use in tires shows easily that it is BUNK. You don't even have your facts right... moisture is what expands?

    All horse****. Nitrogen expands and contracts with temperature just like any other gas. You know air is 70% nitrogen, right? The "much" lower escape/diffusion is crap too. There may be some minuscule difference between 70% nitrogen (air) and 99% nitrogen, but playing it up as if you're going to stop having to put air in your tires all the time is complete BS. You think people believe this crap? People that have air in their car tires and NEVER have to add any?
    You bought somebody's sales pitch and use it because it's no cost to you and now are slinging it as if the science supports it when you don't have a single fact straight.


    FIFY
    Educate yourself, dood. You are ignorant of the facts here.
    You are so incorrect. You are the ignorant one here. The science is real. You just choose not to believe it. I don't pay for it, it is FREE for me. I can tell you one more simple anecdote. My personal tPMS moves about 1 psi over a 150 miles of pure driving. It goes up 10 psi on straight air. You can put your head in the sand about the facts,but they add up. All gases are not reactive the same as you imply. Of course gases expand and contract, air does it much greater as the moisture expands.

    At what point did I imply you don't have to fill your tires up? There is a much longer period between required fill ups. It is why RV's that sit run it. My conversion van hasn't seen a drop in PSI in months. Read my posts twice to improve your comprehension dood (thought it was dude).

    I have never said there is some magical performance enhancement, you won't see the difference in lap times etc...I have seen the science, and it exists. Major auto mfg have no vested interests in Nitro, but have all agreed to the benefits. I understand skepticism on the dollar front, but just don't know how you guys think the facts can be debunked! But hey, that's your opinion to ignore it.

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    Quote Originally Posted by One Pivot View Post
    More fun regarding this topic. At the last place I worked, I went to go investigate the "nitrogen" machine.

    It was a huge box connected to our shop air with a water trap on it. It was really big and looked like it might store compressed gas, but it didnt. It was a water trap with a digital filter, and we'd charge people $40 to fill their tires with it and put those green caps on. This is a very common nitrogen setup. Its a flat out scam.
    Why is is a flat out scam? You're machine isn't converting it to Nitro? With our race bikes (motorcycles) we don't use that machine. We are using pure Nitro tanks (old school). Our racers love it as the come off the track, we notice that bikes going for about 25 minutes at massive centrifugal forces, speed in excess of 170+ and they come in with near the same pressure they left.

    Compared to regular air, there is a significant change. I don't see bicycles with some major improvement running nitro because there is a major difference. However, keeping the moisture out of the rim is a nice thought. Not sure I'd pay someone for running nitro in my bicycle tires though...luckily, I don't have to.

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    The car manufacturers say NO to nitrogen. Im almost sure they all dont recommend it directly. The ones that dont just dont have a policy on it. Im definitely sure none spec it as necessary.

    You're not getting a 9psi difference between nitrogen and air. The tests have been done, thats not possible.

    Its a scam because tire shops are charging people money for literally zero benefit. Its stealing money from people.

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    Sort of. From the top: Air is 78 percent nitrogen, just under 21 percent oxygen, and the rest is water vapor, CO2 and small concentrations of noble gases such as neon and argon. We can ignore the other gases.

    There are several compelling reasons to use pure nitrogen in tires.

    First is that nitrogen is less likely to migrate through tire rubber than is oxygen, which means that your tire pressures will remain more stable over the long term. Racers figured out pretty quickly that tires filled with nitrogen rather than air also exhibit less pressure change with temperature swings. That means more consistent inflation pressures during a race as the tires heat up. And when you're tweaking a race car's handling with half-psi changes, that's important.

    Passenger cars can also benefit from the more stable pressures. But there's more: Humidity (water) is a Bad Thing to have inside a tire. Water, present as a vapor or even as a liquid in a tire, causes more of a pressure change with temperature swings than dry air does. It also promotes corrosion of the steel or aluminum rim.

    If I ever need to top off a tire when I'm out on the road, I'll always briefly depress the tire chuck's valve with my thumbnail and vent some air. If my thumb gets wet, there's water in the line. Some gas stations don't do a very good job of keeping the humidity out of their air system. I don't even like to use a water-based tire-mounting lubricant unless I can let the tire bake in the sun for a couple of hours before I air it up and seat the bead. I've dismounted tires (not mine) that had several quarts of water inside—probably from a compressed-air hose that collected water and was never purged properly.

    How is water relevant to a nitrogen discussion? Any system that delivers pure nitrogen is also going to deliver dry nitrogen. Filling tires with nitrogen involves filling and purging several times in succession, serially diluting the concentration of oxygen in the tire. This will also remove any water.

    It's certainly simple, although time-consuming, for a tire technician to fill and bleed tires. But most shops use a machine that not only generates almost pure nitrogen by straining the oxygen out of shop-compressed air, but will also automatically go through several purge cycles unattended. Some shops have been charging as much as $30 per tire for this service. I think that's too much. If you're buying a new tire, it should be far less. Still, the nitrogen generator, filling system and technician's time aren't free—the dealer is entitled to some return for that.

    So, to answer your specific questions: With nitrogen, your tire pressures will remain more constant, saving you a small amount in fuel and tire-maintenance costs. There will be less moisture inside your tires, meaning less corrosion on your wheels. You will not be able to feel any difference in the ride or handling or braking, unless your tire pressures were seriously out of spec and changing to nitrogen brought them back to the proper numbers. -popular mechanics

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    We'll go for a ride sometime (:

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    Gay lussacs law is that p1/t1 = p2/t2. Pressure and temperature. What you're saying is literally impossible and defies gas laws. If temperature rises, pressure rises.

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    Executive summary:
    you start riding at 95F and ride until the day cools off to 77 F. Your tires with dry air dropped pressure from 30 to about 28.8. If your tires had saturated air the pressure dropped from 30 to 28.3. A difference of around .5 psi.

    Calculations:

    The combined gas law at constant volume.
    P1/T1 = P2/T2


    P1/P2 = T2/T1

    Going from freezing to 104F ( 0 to 40 C as I used in my moisture example)

    P1/P2 = 313k/273k = 1.15

    So going from the hot summer rainforest to freezing winter the pressure change due to the ideal gas behavior is 15% where as the moisture condensation effect I showed above to be about half that amount or 8%.

    So lets be practical. For extreme, unrealistic temperature changes you need to add air to your tires before you ride. If you filled your tires to 30 psi on the hottest day of the summer and then a snowstorm suddenly came in the next day, your tire preessure went from 30 to 26 if it was dry air, and maybe down to 23 if it was saturated air.

    More typical situations would be 10 degree max fluctuation during a ride would cause a 4% change just due to the temperature, 1.5% additional for saturated air (that would condense 15g/kg water from 35C to 25C).

    So you start riding at 95F and ride until the day cools off to 77 F. Your tires with dry air dropped pressure from 30 to 28.8. If your tires had saturated air the pressure dropped from 30 to 28.3. A difference of around .5 psi.

    If you are bored with this analysis, you should be, because it is trivial.

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    Quote Originally Posted by everything motorcycl View Post

    First is that nitrogen is less likely to migrate through tire rubber than is oxygen, which means that your tire pressures will remain more stable over the long term.
    How much longer could you wait to top off your tires using nitrogen vs dry air due to the diffusivity difference? Trivial I would guess. Super trivial for bike tires I am sure.

    Racers figured out pretty quickly that tires filled with nitrogen rather than air also exhibit less pressure change with temperature swings. That means more consistent inflation pressures during a race as the tires heat up. And when you're tweaking a race car's handling with half-psi changes, that's important.
    There would be ZERO difference between nitrogen and dry air in pressure fluctuations due to temperature.

    Passenger cars can also benefit from the more stable pressures. But there's more: Humidity (water) is a Bad Thing to have inside a tire. Water, present as a vapor or even as a liquid in a tire, causes more of a pressure change with temperature swings than dry air does.
    The effect is trivial as I showed above.

    It also promotes corrosion of the steel or aluminum rim.
    I doubt there has ever been one case of a problem with corrosion of a bicycle rim due to water inside a tire. Ever. Search the forum. No issues. It just doesn't happen.

    Your reasons for nitrogen are reasons that don't matter, and are really more misconceptions about water and have nothing to do with nitrogen.

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    Quote Originally Posted by meltingfeather View Post
    My tires are full of sealant... Which is about half water.
    I should definitely focus on putting dry nitrogen in there, right?

    Bingo. I think this is the bottom line. Since the current standard set up for a mountain bike tire these days is a sealant filled tire, then the discussion about moisture is a moot point.

    And during the transition from tubes to tubeless, I never recall one comment ever about how the tubeless set ups with sealant caused more pressure fluctuations. It's a complete non-issue.

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    Quote Originally Posted by One Pivot View Post
    Gay lussacs law is that p1/t1 = p2/t2. Pressure and temperature. What you're saying is literally impossible and defies gas laws. If temperature rises, pressure rises.
    kinetic molecular theory. the temperature of a gas increases, the gas particles move faster and faster...but doesn't mean that ALL gases expand at the same rate. Going to move on...

    Nitrogen WORKS. Been proven.

    My last point again...I would NOT likely BUY nitrogen, but clearly can attest to the fact that it has proven benefits. At least in my opinion. Not one argument or post has even remotely contested this.

    In bicycles, my opinion is, there is a benefit from lack of moisture...mostly for the sake of it is better for the rim, will not lose pressure as quickly. Albeit nominal on bicycles. I see you arguing science. The attempt to Gay/Lussac's Law is applicable, but you can't state that all molecules behave/react the same...they just don't, or you would only have one named gas.

    Enjoy. Have to go fill my tyres, cheers.

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    Quote Originally Posted by smilinsteve View Post
    How much longer could you wait to top off your tires using nitrogen vs dry air due to the diffusivity difference? Trivial I would guess. Super trivial for bike tires I am sure.



    There would be ZERO difference between nitrogen and dry air in pressure fluctuations due to temperature.



    The effect is trivial as I showed above.



    I doubt there has ever been one case of a problem with corrosion of a bicycle rim due to water inside a tire. Ever. Search the forum. No issues. It just doesn't happen.

    Your reasons for nitrogen are reasons that don't matter, and are really more misconceptions about water and have nothing to do with nitrogen.
    Nitrogen is an alternative to 'air'. Where/how do you get your 'dry' air??? You won't see me state Nitrogen is great on its own...it is better then 'air'. If you are now stating "dry" air is the same, you are simply proving my point that 'air' isn't the best alternative.

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    Quote Originally Posted by everything motorcycl View Post
    We can all make opinions, draw conclusions. For me, the science is there on the benefits of Nitrogen. Is it worth it to pay for it? That is a personal opinion. I don't pay for it, so yes. 100% that it doesn't have the 'moisture'. There is little to no expansion or delta pressure. Much less loss in escape/diffusion through rubber matrix and bead.

    What is all that worth to you? That is subjective. But for all the haters saying it is doesn't work, they are defying science. It may not be to a significant amounts for one to pay. I'm not arguing that point. I'm on the side of science.
    You are an idiot.

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    Quote Originally Posted by craigsj View Post
    You are an idiot.
    That's besides the point. Speaking of which, at least I can make a point

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    Popcorn anyone?
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    Quote Originally Posted by Cleared2land View Post
    Popcorn anyone?
    I've left the date (:

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    Quote Originally Posted by everything motorcycl View Post
    kinetic molecular theory. the temperature of a gas increases, the gas particles move faster and faster...but doesn't mean that ALL gases expand at the same rate. Going to move on...
    The BS is nauseating here.
    Any gas in a tire is going to behave the same in terms of PVT relationship. It's the ideal gas law. Any rational you want to try to use to say the ideal gas law does not apply is completely wrong for the case of tires. Now you are trying to argue against very basic physics. You can't win that.

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    Quote Originally Posted by everything motorcycl View Post
    Nitrogen is an alternative to 'air'. Where/how do you get your 'dry' air??? You won't see me state Nitrogen is great on its own...it is better then 'air'. If you are now stating "dry" air is the same, you are simply proving my point that 'air' isn't the best alternative.
    Compressors with air dryers are common. Bicycle tire pumps in dry climates provide dry air as well. It doesn't matter though because the moisture content doesn't matter, as discussed above.
    The fact that MTB tires are filled with water based sealant makes it matter even less.
    Your points are all weak and have all been blown apart already. Now you are just being a troll.

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    Quote Originally Posted by everything motorcycl View Post
    I've left the date (:
    You should have been an advisor for Tom Brady's deflategate problem. Even the best BSers money could buy didn't think to try the moisture angle.


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    Hilarious thread...

    N2 is largely used in racing to cut on the delta from cold to hot psi, make things a bit more stable from one set of tire to another.

    You can bring all gas formula and all sort of voodoo $hit to the table but unless you can ride a bicycle to the point where the tire temp can go from ambient to about 160F... won't do anything on rising tire pressure while you ride.

    So, bottom line... keep using your bicycle pump! LOL

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    I'm gonna start ordering N2 cartridges and throw away my CO2's
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    Quote Originally Posted by Cleared2land View Post
    I'm gonna start ordering N2 cartridges and throw away my CO2's
    Better double check your molecular velocity first.

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    Quote Originally Posted by smilinsteve View Post
    The BS is nauseating here.
    Any gas in a tire is going to behave the same in terms of PVT relationship. It's the ideal gas law. Any rational you want to try to use to say the ideal gas law does not apply is completely wrong for the case of tires. Now you are trying to argue against very basic physics. You can't win that.
    and why do they use it in airplanes? Race vehicles etc? Damn, I keep getting sucked back in...I'm outta here...

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    Quote Originally Posted by smilinsteve View Post
    You should have been an advisor for Tom Brady's deflategate problem. Even the best BSers money could buy didn't think to try the moisture angle.

    He loves moist balls

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    Nitrogen in bike tires?

    I think one aspect which hasn't been spelled out in the theorized temp/pressure differential with air vs N2 is the fact that it's the water moving between liquid and gas states that might be the reason you would see a difference. The change in state results in a large and dramatic change in volume compared with the PV=nRT effect.

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    Quote Originally Posted by smilinsteve View Post
    Better double check your molecular velocity first.
    I did convert and calculate my Kelvins and Molar Mass weights in my Root Mean Square Velocity of Gas Particles equation...did I miss something?
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    Quote Originally Posted by dischucker View Post
    I think one aspect which hasn't been spelled out in the theorized temp/pressure differential with air vs N2 is the fact that it's the water moving between liquid and gas states that might be the reason you would see a difference. The change in state results in a large and dramatic change in volume compared with the PV=nRT effect.
    That has indeed been spelled out very clearly in this thread. Still trivial. See my posts.

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    Quote Originally Posted by everything motorcycl View Post
    and why do they use it in airplanes? Race vehicles etc? Damn, I keep getting sucked back in...I'm outta here...
    The reasons (which you can google), don't apply to bicycles.

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    I'm gonna print me a Cheat Sheet to carry on my rides so that if I suffer a flat in the field, I will be able to whip out my TI 83 interactive reverse gongculating and graphing calculator and whip out some inflation adjusted data so I'm on cue.
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    This pretty much says what all my calculations said. No significant difference for bike tire conditions.

    Edit: Just to be clear, a dry air line would fall exactly on top of the (dry) nitrogen line.
    Attached Thumbnails Attached Thumbnails Nitrogen in bike tires?-n2-vs-moist-air.jpg  


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    Nitrogen in bike tires?

    Quote Originally Posted by everything motorcycl View Post
    and why do they use it in airplanes? Race vehicles etc? Damn, I keep getting sucked back in...I'm outta here...
    -20F to 134F pressure test.
    ZERO difference between nitrogen and air.
    link
    What you have is white-knuckled faith in a myth, not a grasp of simple, measurable facts (science).
    Think about it... educate yourself. Don't just google and copy-and-paste like you have been doing (it's easy to find the pages you plagiarized).
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

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    Quote Originally Posted by Cleared2land View Post
    I'm gonna print me a Cheat Sheet to carry on my rides so that if I suffer a flat in the field, I will be able to whip out my TI 83 interactive reverse gongculating and graphing calculator and whip out some inflation adjusted data so I'm on cue.
    Also don't forget to bring a nitrogen canister.

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    Quote Originally Posted by Cleared2land View Post
    I'm gonna print me a Cheat Sheet to carry on my rides so that if I suffer a flat in the field, I will be able to whip out my TI 83 interactive reverse gongculating and graphing calculator and whip out some inflation adjusted data so I'm on cue.
    Just lay your hands on the tire and heal it with faith and prayer.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

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    ^^^ You know, that might be easier.
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    Nitrogen in bike tires?

    Quote Originally Posted by meltingfeather View Post
    -20F to 134F pressure test.
    ZERO difference between nitrogen and air.
    link
    What you have is white-knuckled faith in a myth, not a grasp of simple, measurable facts (science).
    Think about it... educate yourself. Don't just google and copy-and-paste like you have been doing (it's easy to find the pages you plagiarized).
    Luckily I have educated myself over many years and have the PhD to show for it, so I'll bite ;-)

    First, I totally agree that Nitrogen in bike tires is crazy and wouldn't make a lick of difference. But I don't agree that there is no effect in theory or in practice for F1 cars and jet planes.

    If this link were to a peer reviewed journal article I'd agree with you. But his experiment is badly flawed and can only claim that air of (unknown) humidity has no affect.

    It's clear the author has no idea what the argument is about dry vs humid air is actually based on. He confuses it with liquid CO2 and gas CO2 and doesn't mention water vapor or liquid water.

    No - it's related to the fact that when water moves from the solid state to the liquid state it expands at a rate that does NOT follow PV=nRT (which only works for gases in a continuous gas state).

    Water expands from liquid to gas by a factor of 1600-1700.

    Let me spell that out - 1 cubic inch of liquid water will expand to take up an equivalent volume of 1600 cubic inches when a gas.

    https://en.m.wikipedia.org/wiki/Steam

    This rate of expansion is what drives the turbines in a coal/nuclear power plant. If any old gas did the same, then they'd just used air instead of water.

    His controls are meaningless without a measure of the relative humidity of the air he used, which is not reported.

    He also needs a 100% vs 0% (relative humidity) air controls in the comparison as well as with some liquid water present in the canister (remember the car tires that often have water in them). This is the real experiment!

    I don't have an issue with F1 cars and jet planes using N2 as it makes sense in those specialized conditions and I've no doubt it does make a difference - which is why they do use N2. In normal cars and mountain bikes I agree it's a total waste of time.

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    Quote Originally Posted by dischucker View Post
    Luckily I have educated myself over many years and have the PhD to show for it, so I'll bite ;-)

    First, I totally agree that Nitrogen in bike tires is crazy and wouldn't make a lick of difference. But I don't agree that there is no effect in theory or in practice for F1 cars and jet planes.

    If this link were to a peer reviewed journal article I'd agree with you. But his experiment is badly flawed and can only claim that air of (unknown) humidity has no affect.

    It's clear the author has no idea what the argument is about dry vs humid air is actually based on. He confuses it with liquid CO2 and gas CO2 and doesn't mention water vapor or liquid water.

    No - it's related to the fact that when water moves from the solid state to the liquid state it expands at a rate that does NOT follow PV=nRT (which only works for gases in a continuous gas state).

    Water expands from liquid to gas by a factor of 1600-1700.

    Let me spell that out - 1 cubic inch of liquid water will expand to take up an equivalent volume of 1600 cubic inches when a gas.

    https://en.m.wikipedia.org/wiki/Steam

    This rate of expansion is what drives the turbines in a coal/nuclear power plant. If any old gas did the same, then they'd just used air instead of water.

    His controls are meaningless without a measure of the relative humidity of the air he used, which is not reported.

    He also needs a 100% vs 0% (relative humidity) air controls in the comparison as well as with some liquid water present in the canister (remember the car tires that often have water in them). This is the real experiment!

    I don't have an issue with F1 cars and jet planes using N2 as it makes sense in those specialized conditions and I've no doubt it does make a difference - which is why they do use N2. In normal cars and mountain bikes I agree it's a total waste of time.
    Since there was no difference between the air and nitrogen it seems pretty obvious that the air was fairly dry, but we're not really concerned with common sense or perspective here, are we?
    You misinterpreted his comment about liquid CO2.
    We're missing the forest for the trees, and it seems people are more interested in proving there is some shred of validity in some small slice of what's being presented here when viewed from just the right perspective than the net effect, which you admitted in your second sentence.
    Thanks for the link on steam and for spelling out what a "factor of" means. Douchebag needle pegged on that one.
    The fact that people do something is not a demonstration that the practice is valid. People at high levels of competitive sports do plenty of dumb stuff and have always.
    Also, nobody said that there is no effect in theory or practice for F1 cars or airplanes. One experienced posted did relate a race car experience, but this is a bike forum and we're talking about bike tires. The fact that you need to bring up totally irrelevant subjects to scramble for some shred of rightness to hang on the wall next to your PhD should indicate the weakness of the argument.
    I'm off to more fruitful pursuits. Enjoy!
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  80. #80
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    It would be interesting to know if Nitrogen filled tubeless setups would perform any better. Maybe the tire sealant would behave a little differently? It would be cool to find a solution to tubeless tires leaking a little psi every day. Maybe Stans would last longer too?

  81. #81
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    Quote Originally Posted by Wagon650B View Post
    It would be interesting to know if Nitrogen filled tubeless setups would perform any better.
    No.
    You're welcome.
    /thread
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  82. #82
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    Going to try Stan's new Race sealant next.

  83. #83
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    Quote Originally Posted by Wagon650B View Post
    Going to try Stan's new Race sealant next.
    Much better plan! I'm about to mount up some new Morsa 2.3's. I'll be using a mixture of 78% Nitrogen, 21% Oxygen and some water vapor with a proprietary mix of other gasses and small particles. It's the only way to keep the graphene from getting frizzy.

    I do want the Stan's Race formula. Vittoria has some called Pit Stop. It comes in a thicker race like version also.
    My name is Chris and I ride a Prophet 650b with a Lefty.

  84. #84
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    Quote Originally Posted by Prophet Julio View Post
    I'm about to mount up some new Morsa 2.3's. I'll be using a mixture of 78% Nitrogen, 21% Oxygen and some water vapor with a proprietary mix of other gasses and small particles.

    Ok, that's going to get a few thinkin' Good one!
    A bad day of cycling is better than a good day at work

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  85. #85
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    Quote Originally Posted by Wagon650B View Post
    It would be interesting to know if Nitrogen filled tubeless setups would perform any better. Maybe the tire sealant would behave a little differently? It would be cool to find a solution to tubeless tires leaking a little psi every day. Maybe Stans would last longer too?
    I use nitrogen to set tubeless tires because I don't have a compressor. The bead sets with about 5psi in the tire, then I pump it the rest of the way with a floor pump. There's no noticeable difference in performance.

  86. #86
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    Quote Originally Posted by Prophet Julio View Post
    Much better plan! I'm about to mount up some new Morsa 2.3's. I'll be using a mixture of 78% Nitrogen, 21% Oxygen and some water vapor with a proprietary mix of other gasses and small particles. It's the only way to keep the graphene from getting frizzy.
    don't be that guy, and tell us what is in the "proprietary mix of other gasses and small particles".

    Quote Originally Posted by Prophet Julio View Post
    I do want the Stan's Race formula. Vittoria has some called Pit Stop. It comes in a thicker race like version also.
    I used Pit Stop in the past and it worked ok, no complains at all, but never eared of thicker version. Is it new?

  87. #87
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    Quote Originally Posted by Prophet Julio View Post
    Much better plan! I'm about to mount up some new Morsa 2.3's. I'll be using a mixture of 78% Nitrogen, 21% Oxygen and some water vapor with a proprietary mix of other gasses and small particles. It's the only way to keep the graphene from getting frizzy.
    .
    Quote Originally Posted by Aglo View Post
    don't be that guy, and tell us what is in the "proprietary mix of other gasses and small particles".
    Hint...You're breathing it
    A bad day of cycling is better than a good day at work

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  88. #88
    damned rocks...
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    You know that I know that's air, right?

  89. #89
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    Orange Sealant vs new Stan's Race Sealant? Anyone who's honestly tried both and give a good comparison ?

  90. #90
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    Quote Originally Posted by Cleared2land View Post
    Hint...You're breathing it

    Correct! You are cleared to land.

    Or should it read, Cleared2land, you are correct?!
    My name is Chris and I ride a Prophet 650b with a Lefty.

  91. #91
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    Quote Originally Posted by Wagon650B View Post
    Orange Sealant vs new Stan's Race Sealant? Anyone who's honestly tried both and give a good comparison ?
    I heard Orange Seals new endurance has Nitrogen impregnated poly alloy particles.



    Hummm
    Hummm

    Umm
    -
    -
    -
    I mean it has glitter
    Lead by my Lefty............... right down the trail, no brakes.

  92. #92
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    Quote Originally Posted by ziscwg View Post
    I heard Orange Seals new endurance has Nitrogen impregnated poly alloy particles...
    Holy crap! What more you want in a sealant? The only thing better would be if it was organic, biodegradable, 100% natural, environmentally friendly, non-gmo and not tested on animals.

  93. #93
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    ^^^ Can it put it on my oatmeal?
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  94. #94
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    It would be cool if the psi in tire remained unchanged for a week or two

  95. #95
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    ^^^ I think PSI stabilization is more a function of the tire and not so much the sealant.

    I'm using Stan's and Ardent's that is thoroughly sidewall coated and they are pretty pressure stable for a a week or more.
    A bad day of cycling is better than a good day at work

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  96. #96
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    Quote Originally Posted by Cleared2land View Post
    ^^^ Can it put it on my oatmeal?
    Inadvisable. Causes constipation. Permanent, 100% constipation.

  97. #97
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    Quote Originally Posted by ziscwg View Post
    Dude, go big, go hydrogen!!!!!!!!!!!!!!!!!!!!

    I use it in the air cart on my Lefty. Around this time of yr my lefty doubles as my front suspension and a fireworks show. I just loosen the valve to get some flow and lite it. It's a great 30 sec show.............
    Winner!
    "Life is way too short to own anything crappy"

  98. #98
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    Quote Originally Posted by Lone Rager View Post
    Holy crap! What more you want in a sealant? The only thing better would be if it was organic, biodegradable, 100% natural, environmentally friendly, non-gmo and not tested on animals.
    I tested it. So, the not tested on animals is a fail
    Lead by my Lefty............... right down the trail, no brakes.

  99. #99
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    I only use hydrogenated helium antibodies in my tires. More traction, less effort.
    A bad day of cycling is better than a good day at work

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  100. #100
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    Quote Originally Posted by ziscwg View Post
    I tested it. So, the not tested on animals is a fail
    That's test by an animal, not on animals.

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