General: [Sink] other than air

LOL, are you serious? Helium might give you less rolling resistance...

Tell you what: Why don't you try to fill your tires with helium or hydrogen, ride them around for awhile, and then report back with the results? One of the classic markers of an ill-advised or unimplementable idea is that it begins with: "You know what you ought to do is...".

I've kept my own counsel through a lot of silly posts from you, because you're a kid; I've been waiting for you to grow out of it. I've also kept out of the arguments because you're my Bay Area landsmann (the rest of these auslanders may not know what Millbrae-to-Davis means, but I do). But I find your posts to be the very definition of sophomore, which I'm guessing is exactly what you are, Aggie.

You know what you ought to do? Borrow a camera or use your cellphone, and post a photo of your actual bike, or stop jerking us around. It's not funny, and it was never clever. And I call the whole thing a big Rule 1 violation.

Nitrogen would work. And it would be less affected due to temperature...

Helium has been done on the track. It saves about 5-10 grams per wheel depending on wheel size and tire pressure. The problem is that helium leaks like crazy through the tube rubber, so the tire won't hold its pressure for very long.

Posted By: ragnar.jensenThe problem is that helium leaks like crazy through the tube rubber, so the tire won't hold its pressure for very long.

Of course it does. The molecules are smaller than the molecules of the latex.

show your bikes licked or say you dont have any.

Argon gas is very stable temperature wise. They use it in F1.

Posted By: eaglerock
That is, I'd say that if the original question hadn't been a Merry Prankster masturbatory one to begin with, which it was.

Ditto.

Easily offended? Hardly.... You're giving yourself way too much credit. You've set a precedent for yourself with your constant stream of asinine posts. I generally ignore them and move along, but god damn... enough is enough. Honestly, I could care less who you are, or what bikes you ride. I'm just calling it for what it is ...

oooo0
(....) 0oooo
.\...(.(....)
..\..)..)../
.......(../..........i can hold two pieces of doo-doo in my hand!.............this thread is.....what it is!

Posted By: wes m.stupid threads.

that's an opinion that i don't share about what i post. So either ask for the ban on me for what you think is trolling or don't read my posts. I don't really care if i get banned. I'll know I did something wrong and won't come back. It's all you really care. there are legit posts that are on topic so i don't feel like i've trolled.

Interesting..

I agree with all of the above, H2 and He are going to go through a tire PDQ so are just not used for that reason alone.

Just think about your average low pressure helium balloon the day after it was filled.

But as an academic exercise.. All ideal gases follow the relationship PV=nRT; where P is pressure in Pa, V is volume in m^3, n is number of moles, R is the universal gas constant (8.31 J /mol K), and T is temperature in Kelvin (Celsius + 273.15).

We want to compare two tires both with same pressure, volume and temperature so we know they will both have the same number of moles of whatever gas we use.

So without any math we can see the weights will be directly related to their molar mass / molecular weight.

H2 is 2.02 g/mol, He is 4.0, H2O is 18, N2 is 28, O2 is 30, Ar is 39.98, CO2 is 44 g/mol.

So relatively you would only need (2.02/28) ~ 7% of the mass of Hydrogen gas to fill a tire that would otherwise be filled with Nitrogen. But again, no one does this because it is likely way too cumbersome and would just deflate very very quickly.

As for absolute weights, we need to actually pin down pressures volumes etc.

P lets say is 100psi and convert via 6.894x10^3 (Pa/psi) but since it is a gauge pressure we have to add the pressure of the atmosphere, a nominal 101kPa. Overall (100psi)(6.894x10^3 Pa/psi)+(101000 Pa) = 7.904x10^5 Pa

V I'm going to have to fudge a bit, I'll use a 700x23c tire aka 23-622 tire and use half the bead seat diameter and half the inner diameter as the radius from center of tube to center of torus, and radius of tube. So V = 2 pi^2 R r^2 = 2 pi^2 (622mm/2) (23mm/2)^2 (1 m^3/(1000^3 mm^3)) = 8.12x10^-4 m^3

T lets assume 25 Celsius (77F) = 298.15K

So n = PV/RT = ( 7.904 x 10^5 )(8.12x10^-4)/((8.31)(298.15)) ~ 0.26 moles.

So H2 would weigh ~ 0.5g while Nitrogen would weigh ~ 7g, CO2 would weigh 11g.

Since CO2 is used as a common gas for filling tires I guess convenience outweighs any weight savings. (slightly heavier tires but smaller "pump" that can be tucked away aerodynamically).

Mind you the volume is approximate and is likely an underestimate, but since the temperature I chose was cool the differences should balance out. Of course with pressures more than 100psi you can adjust as required.

The 5 to 10 grams savings mentioned by ragnar is reasonable and sounds like a measured result.

Posted By: CANosprayPAINToooo0
(....) 0oooo
.\...(.(....)
..\..)..)../
.......(../..........i can hold two pieces of doo-doo in my hand!.............this thread is.....what it is!

Yay! De La Soul!

Posted By: lickedwickedthere is a device that lets riders instantly inflate their tubes with those bb gun co2 cartridges.

this is old news.

Most people I knew used those co2 inflators in order to crack nitrous chargers for doing whipits.

Posted By: Aaron Ci think more PS Lickedwicked images are in order.

We all know there is plenty of material to use of him on the interweb.

Ask, and Ye Shall Receive - PSD file of head cut out





NSFW

those aren't me but continue if you please. worst you could do is hurt my cousin who doesn't even come here.

Hahahahaha!!!

Oh Velospace how I love thee

Posted By: lickedwickedthose aren't me but continue if you please. worst you could do is hurt my cousin who doesn't even come here.

ahhhhhh! lickedwicked has a cousin named lickedwicked! wait, what? my mind is so fucked...

wow. is it just me or is everyone just crying their little eyes out over this? seemed to me like licked has a legit question about what goes into your tires and how it affects your ride. give the guy a break. stop wasting time at work to bitch the guy out. remember: IT'S JUST THE INTERNET.

headydude, you would be right if you werent talking about the same kid whom has posts 6 discussions in the last 3 days.
The same kid who posts questions like:

Just like cars are should bikes be hands free?

how does music affect fashion and vice versa?

celebrities and fixed, good or bad?

when I see an unlocked bike that's not mine, should I deflate either or both tires to deter thieves?

Are conversions safer than a track drop out? When the chain snaps, the axel can still be held in the frame. But in track drop outs the wheel can slip off.

are the differences so big that it's a seperate catagory of bike? i don't see the need for a special type of bike when the bike used is only a small portion of the race.

Has anybody ever found a good deal on ebay and won it? How good are deals on ebay?

Posted By: wes m.

Posted By: lickedwickedi'll feel like a martyr one day. when generations after me look back, you'll be the villain.

Someone incorporate this into the lickedwicked spoke card asap!

shit i think i deleted that off my desktop!

done and done...

The best part of waking up is Folgers in your cup.

i can't stop laughing

Hahaha! Good lord ladies and gentlemen he's back and in rare form.

i'll feel like a martyr one day. when generations after me look back, you'll be the villain.

Imma print some t-shirts I swear I am.