Automatic Bicycle Pump




Fill your bicycle wheels with conveniently available pressurized air stored in automobiles.

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Step 1: Materials

You need a 50cm-100cm long air hose and two chucks. Make sure the hose fits very tightly on the chucks.

Step 2: Assembly

Push the hose onto the chucks. It should be a very tight fit. If it is too tight you can soften the hose by heating it in warm water.

Step 3: Steal Some Air!

Take your bike and go find a hummer (or some other overweight vehicle). Fold the hose in your hand so you don't waste any precious energy. Attach one end to the automobile tyre and the other to your bike. When you unfold the hose you can hear a hiss. That is the sound of air flowing to your bike wheel and the world becoming a better place :) Fold the hose again before you detach it from both vehicles.

Remember! Thou shalt not steal air from public transportation. Public transportation is good.

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    185 Discussions

    Eric Caruyer

    5 weeks ago

    A New must have in cycling bag =)


    8 months ago on Introduction

    Bikes usually need a higher pressure (4 - 5 bars) than cars (1,5 - 2 bars)
    So trucks, buses and other heavy vehicles (8 - 12 bars) are a better choice for this "air vampire trick".
    But keep in mind to not allow the full pressure from a heavy vehicle into your bike tire. It'll go *PoOf* rather quickly. ;)

    Disclaimer: Actual pressures might vary. I only present a "ball park" figure here.


    3 years ago

    yeh. I came up with this in 1967. Same year I invented mag-lev & rail guns. Before I was drenched in insecticide by a crop duster, and I became every other "salt 'o the' urth" american patsy...


    5 years ago on Introduction

    Out of air.. OH! There is a scrapped car there with still inflated tires... "Hiss" There we go. :)

    1 reply

    6 years ago on Step 3

    It would really put an elderly person in a predicament if you "used" their tire's air for your bike tire and stranded them, needing assistance to change their tire! If you ever come back to your vehicle and discover you have two very deflated tires, ( hopefully on the same side! ), you'll know that your instructable was remembered by someone who needed air in both bike tires. What goes around...comes around.


    13 years ago on Step 3

    hell yeah! I'm lovin' this. So simple. I can't believe I didn't think of this or seen this before.

    11 replies

    Reply 8 years ago on Step 3

    Yes, except for the fact that this doesn't work!

    As many have said in this comment section, this will only further deflate your tires, or inflate them to a low point. Believe it or not, bicycle tires require a higher pressure than do car and even truck tires.
    Someone made a remark about it being "common sense" that an automobile have a higher tire pressure, but this is solely based on assumption. And we all know what happens when you assume...

    It's a great concept, but there's no way to practically apply this. The pressure source being suggested in this Instructable is simply inadequate.


    Reply 8 years ago on Introduction

    What you can do is pile weight on the car first thus increasing the pressure. Just looking at my jeep it has, say, at least 80 in^2 of tire in contact with the ground. Of course, the tires will flatten out even more as you add weight and/or suck out air, but let's say to get from 40 psi to 110psi you only need to pile 5,600 pounds on top of the vehicle for an adequate pressure increase. So with a good supply of bricks and rocks you should be in business.

    Brilliant! So instead of carrying around a small hand pump on my bicycle, I'll carry around this air-stealing device, and a mere 5600lbs of bricks! It's fool-proof!


    Reply 8 years ago on Introduction

    Maybe that's why some &%$# piled a bunch of rocks on my Suburban! I was wondering, until I read this 'ible.


    Reply 8 years ago on Introduction

    what about the volume of a car tire vs. a bike tire and the weight of the car increasing the pressure?

    The only way that the weight of the car could increase the pressure is if the tires were inflated before they are installed onto the car. Since car tires are inflated after they are installed on the car, the 35psi that is standard for car tires has *already* taken into account the extra weight of the car compared to the bicycle. 35psi is all it has, tops, and you cannot use a 35psi car tire to inflate a bike tire to anything approaching it's recommended pressure.

    This kind of idea is only useful in an emergency stopgap kind of situation. Like, you're out riding, you get a flat, you don't have a real pump on you, so patch your tire and then you use this trick to get your tire up to 35psi, and then you immediately ride straight home to where you have a real pump to get your tire up to the proper 60-120psi that it likely requires (depending on what type of tire it is).

    This is not the kind of thing where you say "oh, my tire's a little low, I'm gonna go fill it up from a car tire." doesn't work.


    Reply 8 years ago on Introduction

    that kind of depends on the bike too. On the whole I agree with what you're saying but you've over generalized bikes. OK some racing bikes use over 100psi but the majority of mountain bikes are happy in the 40psi range. I knew a guy who had a massive downhill bike with 3" wide tyres and he ran his at about 12psi.
    Stealing air isn't good though. I'd be pretty annoyed if someone did it to me. Not everyone checks their tyres as often as they should.

    most cars are 25 to 35 psi, so the low range of bike tires being 40 psi doesn't really help the case. Also on the big suvs (which he is probably targeting to be green) the tires being low greatly increases wear and adds to the chance of a blowout or a rollover. At any rate it can lower the life of the tire, which is not eco-friendly to replace. I can't imagine why someone would do this instead of getting a little portable pump, bike tires are low volume and topping them off doesn't take long.

    OK for the sake of a few psi I'm finding this all a little pedantic now. Yes I said 40psi, and yes I'm aware that car's tend to be lower than that. The point I was trying to make was that so many people in these comments are talking about bike tyres being over 100psi and they're generally not. 40psi is plenty. OK so you can only steal 30psi from a car (which I still don't approve of) and you're not gonna want to ram a curb and get a pinch flat, but it'll get you home won't it?

    The small change in PSI probably won't matter, but for the cost of these parts you could just get a small hand pump that clips to your frame and inflate your tires without being annoying.