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I know this is a rather controversial issue. I was skeptical as well before doing this on my car, and I have not refilled my car tires for several months. Before that I needed to adjust the pressure every couple of months at least.

Now I think it is a good idea to try this for our bikes. Especially since, when I see I need to fill up my bike tires, I get too lazy and give up the ride altogether.

Is there a way to do this at home?

EDIT: I thought I'd update the question for people who come and read later:

Thanks for all the comments, I drive a lot (30kmiles/year) and I saw (to my surprise) a significant difference with nitrogen.

I understand the reasoning with losing oxygen over time and increasing the N2 concentration but in practice that does not happen fast enough.

I think I'll look into Helium/Argon and I'll update you if I managed to do something interesting.

And I live in a small place I don't like to have a large pump but that is exactly why pumping is such a chore for me,

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  • 17
    (Keep in mind that, since air is 78% nitrogen, and oxygen leaks out faster, if you just keep pumping up your tires as needed pretty soon the nitrogen level will reach 90% or better.) May 31 '13 at 22:42
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    My car tires typically go months between needing refills and I use plain air. How many months' difference are you talking about? Hard to imagine it's worthwhile considering that air is free. Jun 1 '13 at 2:35
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    Get a better bike pump. If you have decent floor pump, filling up your tires shouldn't be a big chore. If you're using those small emergency pumps that you're supposed to bring with you, I can see why you would just rather not ride. But a decent pump is almost effortless.
    – Kibbee
    Jun 1 '13 at 9:34
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    @Kibbee - Agreed. A "floor pump" (the standard upright cylinder with a handle on top) takes up only slightly more room than an umbrella, and is the only way to inflate a bike tire properly. Jun 1 '13 at 11:47
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    Part of the reason bike tires lose air faster than car tires (aside from the thinner rubber of bike tires) is the much lower air volume to surface area of the rubber - so no matter what gas you use, you'll need to pump up the bike tire much more often.
    – Johnny
    Jun 2 '13 at 12:33
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Prestacycle markets a home nitrogen system. Have never used this product. Bit too pricey for me. Personally a floor pump is a better value. Different road conditions means different tire pressures for optimal ride.

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    Yeah, and the expensive nitrogen system won't be any more compact than a floor pump.
    – amcnabb
    Jun 3 '13 at 19:58
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I am going to be presumptuous enough to ask what I believe is the question behind the OPs question, then answer that...

The problem is that you have to inflate the tires more often than you like. The question then is what can I do to ensure my tires remain inflated for as long as possible.

The answers Tubes - these keep the air molecules in. Thicker is better, as is better material. Dump the super thin light weight race tubes and get the thickest one you can find, I would even suggest giving cheap chain store tubes ago.

Tires - Bigger tires can carry the same weight at lower pressures. Put in bigger tires and run at lower pressure. This has two effects - lower pressure leaks molecules slower, and more volume means those leaked molecules are noticed less.

Exotics Look at the no-tubes and 'no puncture' slime solutions - these seal the holes the air molecules are escaping from.

As previously suggested - invest in a decent pump. If you don't have room or desire for a floor pump by the door, get a pump that uses CO canisters (and wear the cost of canisters). If it is still a pain to pump up your tires - discard the plastic valve caps, and get rims/tubes with presta valves - it will take less than 30 seconds to top up two tires.

You might have guessed all these solutions add weight and move away from the best of the best in terms of performance- well, that is expected, nothing is free and super light weight fast racing tires leak air, after all, as long as they stay inflated for the stage - up to 8 Hours, that's all that is needed and any longer is excess weight.

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I can inflate my car tires to proper pressure by checking them once a month or so and inflating them as needed using free air. It takes me maybe 5 minutes per month.

I can inflate my bike tires to proper pressure by checking them once a week or so and inflating them as needed using free air. It takes me maybe 2 minutes per week.

There is no strategy of using alternative gasses that can even remotely compete with that in terms of economy, time or convenience.

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  • You are a lucky man, in my case, I don't regularly use my bike, when on a weekend or an weekday afternoon, I got myself to go for a ride, an almost flat tire is a very good excuse to give up and instead do something else, especially if I need to do the bikes for the whole family, by the time all the bikes are ready everybody started doing something else.
    – Ali
    Jun 2 '13 at 4:57
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    @ali - A good quality bike tube should hold proper pressure for 3-6 days in a high-pressure tire (over 75 psi or so) and longer in a lower pressure tire. So you should not be "surprised" to find a tire flat if it's been 2-3 weeks since your last ride. It takes about 3 minutes to inflate the tires with a good floor pump (with built-in gauge). (You will find that a properly-inflated tire rolls much more easily and makes your ride more enjoyable.) Jun 2 '13 at 11:54
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    @Ali How about making refilling the tires part of the ride? Teach the whole family how to inflate their tires and make it a practice to have everyone inflate their own bike's tires before each ride. Then it's not you doing all the work and the rest of the family getting bored and wandering off. Jun 2 '13 at 21:23
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There is and I have done it with the same setup. I am a diver by trade and I experimented with the same setup. I used a SCUBA bottle and set the regulators with my calibration equipment. I got it to work but it the only value I got from it was knowing that it could be done. The N₂ was expensive, at least compared to air. The SCUBA regulators were expensive and they needed to be precisely set. Calibration is usually not accurate to 1PSI, which you would need. I also didn't want to haul the whole heavy potentially dangerous HP gas setup around with me.

I dove with He on several occasions. That is even more of a hassle. The whole system would leak no matter what. It was because the Helium molecules are so small they can pass through cracks of pipe fittings no matter how tight the fittings were.

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  • That's what I was thinking. If you had an old 1st and kept it at 150 psi (or detuned it a bit) as well as a small bottle, like an AL13, then you might be able to make something useful from stuff you already own. I do wonder what grade of nitrogen they use in car tires and how much places like airgas charge for it. Jun 1 '13 at 14:14
  • Thanks for sharing, so basically you are saying using nitrogen is not practical at least as far we've figured out so far, and Helium is even worse, since it may even leak out more than air,
    – Ali
    Jun 2 '13 at 0:04
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    You said H₂, but I think you meant He -- H₂ is hydrogen, which would not make for a good diving gas and would leak through tires even faster than Helium.
    – Johnny
    Jun 2 '13 at 12:30
  • You can dive with most gasses with a varying degree of success including hydrogen (hydrox). You are correct, the more popular diving gasses for professional and technical diving are helium in heliox or trimix. Jun 2 '13 at 13:19
  • @Johnny: Actually helium leaks fast than hydrogen. Helium gas is made up of single atoms, which are very small. Hydrogen gas is made up of hydrogen molecules, where each molecule is made of two atoms. An individual hydrogen atom is slightly smaller than a helium atom, but the molecule is almost twice as big - so finds it much harder to fit through gaps. Aug 22 '16 at 12:00
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If you have nitrogen inflated car tires then you can syphon (a little) nitrogen off of them into your bike tires. Of course, you'll have to later refill the car tires with nitrogen. (You could even overfill your car's tires at CostCo to help with this.)

Get a Schrader barb at a hardware store. Cut the hose off a Presta/Schrader bike pump and attach the Schrader barb to the cut end. Attach the Schrader end to the car tire and the other end to your bike tire.

This will only work to equalize the pressure between the two, to say 45 psi or whatever your car's tire pressure is. So you'll need something like wide tubeless bicycle tires which are good for such low pressures.

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  • Interesting idea, but there's a risk of ending up with multiple tyres all with insufficient atmosphere in any of them.
    – Criggie
    Mar 30 at 20:13
  • This is all out of the box thinking. A car tire has about 10x the volume of a bicycle tire and it has 4 tires to the bike's 2. Also, you can overfill for the purposes of the experiment. What you can't do is attain a very high pressure with this pressure equalization approach. However, you might be able to directly inflate your bike tires at CostCo and get a higher pressure.
    – Olsonist
    Mar 30 at 21:45
  • Instead of overfilling your car's tyres, fill a portable air tank which are often designed to hold 125 PSI. Car tyres are in the low 30 PSI so you'd never get your bike tyre above that. Running your car tyre any distance at over those pressures is asking for tyre wear and potential blowout, and will compromise grip. Best not-to.
    – Criggie
    Mar 30 at 21:59
  • Outside-the-box thinking leads to complicated solutions. Why not pack the bike in the car, drive to wherever OP fills their car tires with nitrogen and use the same pump for bike tires? Or even simpler, just ride the bike there?
    – ojs
    Mar 31 at 8:51

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