This is cool.

I think the *commercial channel would be appropriate.

Invocations (commercial) cannot be called by Boise_Lib because Boise_Lib is not privileged - sorry.

..what happened when you get a couple nails/shards of glass in 'em?

>> ^GenjiKilpatrick:

..what happened when you get a couple nails/shards of glass in 'em?


I was wondering that too. I would suspect that they would have to buy a new outer tube to surround the aluminum. Great idea, but perhaps not cost effective yet.

*promote

Promoting this video back to the front page; last published Thursday, August 25th, 2011 5:03pm PDT - promote requested by dystopianfuturetoday.

It might actually save money if you could get it to work on car tires. Under inflation can seriously shorten the life of your car tires.

another thought: think about how tired you get pumping a tire from 22 to 52 psi. With the self inflating tire you are still doing the same amount of work.. and while the tire stops filling after reaching the desired pressure, it looks like you keep on working the mechanism with every pedal stroke. That kind of wasted energy can really add up.
Of course, energy is wasted through movement of the tires all the time anyway - just feel them after a ride; they are hot. The trick must be in getting the energy wasted by the pump mechanism to overlap with that energy that would be wasted even with a normal tire.

It doesn't seem very reliable as that part of the tire would wear down first. One hard brake lockup, and it's useless.

I don't get tired at all with a full sized bicycle pump. Bicycle tires just aren't that big. If i could do it with my legs, I doubt I'd even feel it.

>> ^grinter:

think about how tired you get pumping a tire from 22 to 52 psi.

>> ^Nexxus:

It doesn't seem very reliable as that part of the tire would wear down first. One hard brake lockup, and it's useless.


Exactly, that is a major flaw: the mini tube seems to be serious flaw unless it is made of something far more durable than normal tires.

I wish I was self inflating

>> ^Fantomas:

I wish I was self inflating


They have pills for that now.

Looks like he reinvented the wheel...HAAAAAAAAAAAAHAHAHAHHAHAHAHAHA *cough cough*

>> ^grinter:

It might actually save money if you could get it to work on car tires. Under inflation can seriously shorten the life of your car tires.
another thought: think about how tired you get pumping a tire from 22 to 52 psi. With the self inflating tire you are still doing the same amount of work.. and while the tire stops filling after reaching the desired pressure, it looks like you keep on working the mechanism with every pedal stroke. That kind of wasted energy can really add up.
Of course, energy is wasted through movement of the tires all the time anyway - just feel them after a ride; they are hot. The trick must be in getting the energy wasted by the pump mechanism to overlap with that energy that would be wasted even with a normal tire.


The tire should resist being compressed by an amount which would largely depend on the work needed to raise the bike and its rider by fractions of a milimetre per turn of the pedal which would not be very much extra energy to put in. You're also spreading that "pumping up the tire" energy over thousands of pedal turns. I'm almost certain it'd be negligible.

It's similar to putting a dynamo on a bike to power a light - that light requires energy to run, and it has to come from somewhere (the dynamo resists the motion of the wheel turning) - meaning you have to pedal ever so slightly harder. You wouldn't notice.

>> ^dannym3141:

>> ^grinter:
It might actually save money if you could get it to work on car tires. Under inflation can seriously shorten the life of your car tires.
another thought: think about how tired you get pumping a tire from 22 to 52 psi. With the self inflating tire you are still doing the same amount of work.. and while the tire stops filling after reaching the desired pressure, it looks like you keep on working the mechanism with every pedal stroke. That kind of wasted energy can really add up.
Of course, energy is wasted through movement of the tires all the time anyway - just feel them after a ride; they are hot. The trick must be in getting the energy wasted by the pump mechanism to overlap with that energy that would be wasted even with a normal tire.

The tire should resist being compressed by an amount which would largely depend on the work needed to raise the bike and its rider by fractions of a milimetre per turn of the pedal which would not be very much extra energy to put in. You're also spreading that "pumping up the tire" energy over thousands of pedal turns. I'm almost certain it'd be negligible.
It's similar to putting a dynamo on a bike to power a light - that light requires energy to run, and it has to come from somewhere (the dynamo resists the motion of the wheel turning) - meaning you have to pedal ever so slightly harder. You wouldn't notice.


Well, you sort of hit on my point. At first it seems like it would be very little energy, but you are doing the same (or similar) amount of work as you would do when inflating the tire directly (the same job is getting done). I know that others have claimed that they don't get tired when blowing up a tire (no pun intended), but for me it is enough of a job that I wouldn't want to be doing it the entire duration of every bike ride that I ever take.
Similarly, most commuters and people riding bikes for sport don't want to deal with the extra energy (and mass) it takes to drive a dynamo powered headlamp, so they choose a battery powered model instead.

>> ^grinter:

>> ^dannym3141:
>> ^grinter:
It might actually save money if you could get it to work on car tires. Under inflation can seriously shorten the life of your car tires.
another thought: think about how tired you get pumping a tire from 22 to 52 psi. With the self inflating tire you are still doing the same amount of work.. and while the tire stops filling after reaching the desired pressure, it looks like you keep on working the mechanism with every pedal stroke. That kind of wasted energy can really add up.
Of course, energy is wasted through movement of the tires all the time anyway - just feel them after a ride; they are hot. The trick must be in getting the energy wasted by the pump mechanism to overlap with that energy that would be wasted even with a normal tire.

The tire should resist being compressed by an amount which would largely depend on the work needed to raise the bike and its rider by fractions of a milimetre per turn of the pedal which would not be very much extra energy to put in. You're also spreading that "pumping up the tire" energy over thousands of pedal turns. I'm almost certain it'd be negligible.
It's similar to putting a dynamo on a bike to power a light - that light requires energy to run, and it has to come from somewhere (the dynamo resists the motion of the wheel turning) - meaning you have to pedal ever so slightly harder. You wouldn't notice.

Well, you sort of hit on my point. At first it seems like it would be very little energy, but you are doing the same (or similar) amount of work as you would do when inflating the tire directly (the same job is getting done). I know that others have claimed that they don't get tired when blowing up a tire (no pun intended), but for me it is enough of a job that I wouldn't want to be doing it the entire duration of every bike ride that I ever take.
Similarly, most commuters and people riding bikes for sport don't want to deal with the extra energy (and mass) it takes to drive a dynamo powered headlamp, so they choose a battery powered model instead.


Well i mean obviously cyclists cycling for sport won't use any lights to avoid weight, and they have to accurately control such things.

We're talking about the kind of difference between going up some stairs and going up some stairs with a jacket on and after a big meal. It's completely unnoticeable to your strong leg muscles to carry that meal and the jacket up the stairs, but if you stood at the bottom and tried to throw them both up you'd probably find that a bit tiring. Know what i mean? I get your point but i just don't think you'd notice. I cycle a lot and the tiniest things can make it feel easy or tiring, would you notice a miniscule change?

Fair enough though if the potentially large eventual added up calories puts you off.

>> ^Fantomas:

I wish I was self inflating
you can't reach your own valve?

You'll probably never feel the difference, even in a side-by-side comparison, and even if you can, it's not like you're inflating all the time:

1) Inflating from 22 to 52 psi takes maybe 40 strokes of a small, cheap hand pump, and a bit of effort (if your tires take longer or are more difficult to inflate, it's probably because they're higher pressure). Now stretch that same job over 3.5 minutes at (guessing this guy's cadence) a moderate 80 pedal revolutions/minute.

80 revs x 3.5 mins = 280 pedal revolutions
280 revs x 2 pedal strokes (right and left) per revolution = 560 pedal strokes

40 pump strokes / 560 pedal strokes = 1:14, or a touch over 7%

So per stroke you're doing 7% of the work of a hand inflation job. That's just about negligible, considering you're doing it with super-efficient pedal power, not an awkward bike pump.

2) Furthermore, that would only be for the first mile. Everything after that would be just like a normal bike because it would stop pumping. When the tire got a little under-inflated, it would pump for a couple spins of the tire, then be done. You'll never know.>> ^grinter:

>> ^dannym3141:


The tire should resist being compressed by an amount which would largely depend on the work needed to raise the bike and its rider by fractions of a milimetre per turn of the pedal which would not be very much extra energy to put in. You're also spreading that "pumping up the tire" energy over thousands of pedal turns. I'm almost certain it'd be negligible.
It's similar to putting a dynamo on a bike to power a light - that light requires energy to run, and it has to come from somewhere (the dynamo resists the motion of the wheel turning) - meaning you have to pedal ever so slightly harder. You wouldn't notice.

Well, you sort of hit on my point. At first it seems like it would be very little energy, but you are doing the same (or similar) amount of work as you would do when inflating the tire directly (the same job is getting done). I know that others have claimed that they don't get tired when blowing up a tire (no pun intended), but for me it is enough of a job that I wouldn't want to be doing it the entire duration of every bike ride that I ever take.
Similarly, most commuters and people riding bikes for sport don't want to deal with the extra energy (and mass) it takes to drive a dynamo powered headlamp, so they choose a battery powered model instead.

The diagram didn't show how the air gets into a pressurized chamber. Since it's a clincher type tire, and clincher rims don't hold air pressure at all, I'm guessing this tire uses a regular bike tube, and there's an external device from the tire to the tube valve similar to the valve on a bike pump. I'm seeing something like that in the photos of the wheel before the ride. This device would also have to contain a gauge so it would know when to stop putting the air into the chamber.

The only advantage this product provides is eliminating regular maintenance pumping (10 strokes once every few weeks). It does not eliminate the pumping needed when you get a proper flat, because you can't roll with no air in it at all. This product would be aimed only at recreational cyclists who want to occasionally avoid using a pump. Seriously?

Also given that the pump's life is over once that outer tube got cut, that's the whole point of the tire gone. I guess it'd still continue to function as a normal tire, but where's the fun in that?>> ^albrite30:

>> ^GenjiKilpatrick:
..what happened when you get a couple nails/shards of glass in 'em?

I was wondering that too. I would suspect that they would have to buy a new outer tube to surround the aluminum. Great idea, but perhaps not cost effective yet.
[edit]

@grinter @dannym3141

When I said it would stop pumping, I meant it would stop pumping air into the chamber. The lumen may still compress and send air around after the tube was full, but it would release this air into the atmosphere without resistance, so it would give no more resistance than a tire normally does. It's the resistance of air going into a pressurized chamber that makes pumping difficult.

And if the device is really smart, like the graphic kinda indicates, the lumen itself would cease to become inflated at all. If the cut-off is at the air intake, not the pump end, then the device won't even be active most of the time. [edit]

My question is how you could keep the air intake clean in wet and snowy weather.

@messenger that's what i've been saying, only i'm not as sure that the lumen seals itself once fully inflated thus avoiding any further extra work. But i do say that in either case you would still not stand a snowball's chance in hell of noticing it; it would be an act of supreme lazyness to refuse to ride one because of the 'extra effort' involved. Olympic lazyness. Like shaving your head just cos you don't want the added effort of carrying the weight.