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Zippy, the wonder bike
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Why can't you put helium in your tires. I'm serious, will this make any weight differences or not? And is there any reasons that why it can't be done? I would appreciate any answers as I'm seriously considering this.
 

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Doesntplaywellwithmorons!
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the weight difference between helium and air in a small volume application like bicycle tires is MINOR. On a pristine road track it might be useful, but on a mountain bike, the first puddle you go through will likely coat your tires with more enough mud to nullify the weight savings of the helium.

That and its a smaller molecule than the nitrogen, oxygen, and carbon dioxide in air, so it'll seep thru the butyl rubber tubes much faster than air will. Again, track racing supported by a team with helium tanks is fine. Out on the trail though, losing half your pressure over a 4 hour ride is a bit annoying.
 

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Just passing through....
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FLYBYU said:
Why can't you put helium in your tires. I'm serious, will this make any weight differences or not? And is there any reasons that why it can't be done? I would appreciate any answers as I'm seriously considering this.
It'd be far more trouble than it would be worth, IMHO, not to mention the cost.
 

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The weight difference wouldn't be minor. We discussed this not too long ago and it would save 20-40g from my memory, which really isn't little considering that for weight weenies even like 5 g is considered a good saving if it's not too much trouble.

Also is this helium seeping through butyl tubes comes from experience or is this just speculation?!? Cause I don't really see why it would seep just cause its light.

Having said that its just not practical to put helium in your tires. Maybe if you had a bottle in your garage and it didn't cost much, but realistically you'd have to get it at some party shop or something and its just too much hassle despite the weight savings.
 

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Lactic Acid is my friend.
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Also is this helium seeping through butyl tubes comes from experience or is this just speculation?!? Cause I don't really see why it would seep just cause its light.
It's not because it's lighter. It's because the actual helium particles are smaller so they will pass through the butyl tube very quickly. Kind of like a balloon filled with helium versus air. To make a tube that will hold helium for just as long, it will have to be denser, thus heavier.
 

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(enter witty phrase here)
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FLYBYU said:
Why can't you put helium in your tires. I'm serious, will this make any weight differences or not? And is there any reasons that why it can't be done? I would appreciate any answers as I'm seriously considering this.
Try Hydrogen :D You'll be flamming fast.
Seriously though, did you every take your birthday ballons as a kid and tie them to your GI Joe men to make them float? It took like 6 of them just to get Joe to begin to lift up.
You may want to read this: http://www.balloonhq.com/faq/whyfly.html

The weight of the volume of helium in a 2" tube is ~0.66g. And the weight of the volume of air in a 2" tube is ~4.82g. If you're lucky you may save 4g/wheel.

But hey, if you get a 4" tube/tire you can save 8g/wheel. Now we're talking weight savings.
 

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(enter witty phrase here)
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split said:
It's not because it's lighter. It's because the actual helium particles are smaller so they will pass through the butyl tube very quickly. Kind of like a balloon filled with helium versus air. To make a tube that will hold helium for just as long, it will have to be denser, thus heavier.
Correct. This is why rubber ballons go flat the next day. Yet the mylar balloons remain floating for weeks. The mylar is less porus that the rubber balloons.
 

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Just passing through....
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tlg said:
Try Hydrogen :D You'll be flamming fast.
Seriously though, did you every take your birthday ballons as a kid and tie them to your GI Joe men to make them float? It took like 6 of them just to get Joe to begin to lift up.
You may want to read this: http://www.balloonhq.com/faq/whyfly.html

The weight of the volume of helium in a 2" tube is ~0.66g. And the weight of the volume of air in a 2" tube is ~4.82g. If you're lucky you may save 4g/wheel.

But hey, if you get a 4" tube/tire you can save 8g/wheel. Now we're talking weight savings.
I used to work at a gas station right after high school, and we floated an empty oil can into the air, it took approx. 10 average size ballons to lift the empty oil can.
 

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(enter witty phrase here)
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DaFireMedic said:
I used to work at a gas station right after high school, and we floated an empty oil can into the air, it took approx. 10 average size ballons to lift the empty oil can.
Now I'm wondering if I can seal off my camelback and fill it with helium. I calculated that'll save 3.1g.
 

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FLYBYU said:
Why can't you put helium in your tires. I'm serious, will this make any weight differences or not? And is there any reasons that why it can't be done? I would appreciate any answers as I'm seriously considering this.
If you put helium in your tires, it will all rise to the top of the rim. Since there won't be any helium at the bottom of the rim, you will effectively have a flat tire.
Air is heavy, so it settles to the bottom of the tire and keeps it elevated from the ground.
That's how tires work, so no, you can't put helium in your tires.

:rolleyes:
 

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(enter witty phrase here)
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Masher said:
If you put helium in your tires, it will all rise to the top of the rim. Since there won't be any helium at the bottom of the rim, you will effectively have a flat tire.
Air is heavy, so it settles to the bottom of the tire and keeps it elevated from the ground.
That's how tires work, so no, you can't put helium in your tires.:rolleyes:
Not quite. When you put a gas or liquid into a container under pressure, there will be pressure throughout the container. If you fill the tire with less pressure than atmospheric pressure, then you would have the flat condition.
If air is heavy and settles at the botton, why isn't the top flat? It's the pressure (PSI) which keeps the tire elevated from the ground.
 

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Boj said:
The weight difference wouldn't be minor. We discussed this not too long ago and it would save 20-40g from my memory, which really isn't little considering that for weight weenies even like 5 g is considered a good saving if it's not too much trouble.
Just curious, how was this calculated, by theory or by reality (weight difference between deflated and inflated wheel+tire)?
 

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frank n. beans said:
I run my tires at 15psi to save weight. I figure that my bike is almost 35 pounds lighter this way compared to if I inflated both of the tires to 32.
Ya, that's always a good way to reduce alot of weight.

You can also attach bungie cords from your helmet to your top tube. They will help lift the bike off the ground as long as you sit up straight and keep tension on them.
It's amazing, you end up so close to being a human powered hovercraft when you ride like that.
 

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Complete Bastard
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tlg said:
Not quite. When you put a gas or liquid into a container under pressure, there will be pressure throughout the container. If you fill the tire with less pressure than atmospheric pressure, then you would have the flat condition.
If air is heavy and settles at the botton, why isn't the top flat? It's the pressure (PSI) which keeps the tire elevated from the ground.
TLG, calm down. I'm sure he was trying to be funny.
 
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