Helium/Hydrogen filled frame and tires.
Arun Sankaran
I was just pondering about a way to make bikes lighter that seems
very simple to me. Since frames are usually hollow tubing why not seal
the ends and fill them with lighter-that-air gases like helium or
hydrogen. Same goes for the tires. If they were constructed with slightly
different materials they could probably hold these gases in a
preassurized state. Why is this not done? (or is it?)
Comments/Suggestions welcome.
-Arun
Kristan Roberge
Well, the reason it isn't done is the cost of the gases, plus the fact
that hydrogen is volatile.
Also you couldn't seal the seatube of headtube (although you could seal
off the toptube and downtube, plus the seatstays and chainstays.
But if you had bottlecage bolts in the downtube, whenever you remove the
bolts you'd risk letting the helium escape.
Course, the amount of helium you could get inside a frame (to replace the
air that's in there now) would barely fill a decent sized balloon at
a party, which might lift an ounce or two at most. Seems an awful lot
of trouble for a couple ounces.
Kristan Roberge
> My suggestion is to make a bike that is vacuum in the tubes. Nothing weights
> less then something. Right? So make everything on the bike hollow and remove
> the air from inside it. This would make my bike lighter then your helium or
> hydrogen bike by a whole microgram. I could blow past you up a hill any day.
> But would it be because I bike about 200 miles a week or would it be the weight
> difference.
true, that would remove the micrograms of weight of the air, but helium
would not only be lighter, but would also provide some lift to reduce
the effective weight of the bike (part of it is being supported by the
helium).
Kyle Keefe
:After picking myself off the floor due to fits of laughter I wasn't sure if you
:were serious or not. So here goes. Cost to weight ratio, dangerous, and just
:plain wouldn't matter greater scheme of things.
:1st.The air in the tubes now don't weight anything and its free. In a vacuum it
:would have weight but since you are confined to the earth no weight. And how
:much more would it cost to seal the whole bike, I believe a lot more, for what
:a microgram of weight savings. Sorry I will just stick with my Ti bolts and
:nuts.
:2nd The use of hydrogen in a bike tube would be like riding the Hindenburg
:(sp?). One small frame crack and spark and you would need a tube to piss out
:of because (well you know).
:3rd Compressing the gas will not make it any lighter. I f you put more of
:anything in a container, the whole system (i.e. container + anything) would
:weigh more Right. So why compress it?
:My suggestion is to make a bike that is vacuum in the tubes. Nothing weights
:less then something. Right? So make everything on the bike hollow and remove
:the air from inside it. This would make my bike lighter then your helium or
:hydrogen bike by a whole microgram. I could blow past you up a hill any day.
:But would it be because I bike about 200 miles a week or would it be the weight
:difference.
:That was fun.
:TheEverlast
You must be pretty insecure about your ability on a mountain bike, for
you took the opportunity to lambaste a guy for asking a simple question
about a subject for which you have been slightly educated. As for you
being able to "blow past" him up a hill in Illinois, your 200 miles won't
mean shit up here in Colorado. Keep riding by yourself. I'm sure you
are the only one who can stand you.
Peace.
Egil Borgne
momens of interia!
Mike Beyers
: would have weight but since you are confined to the earth no weight. And how
: much more would it cost to seal the whole bike, I believe a lot more, for what
: a microgram of weight savings. Sorry I will just stick with my Ti bolts and
: nuts.
: 2nd The use of hydrogen in a bike tube would be like riding the Hindenburg
: (sp?). One small frame crack and spark and you would need a tube to piss out
: of because (well you know).
: 3rd Compressing the gas will not make it any lighter. I f you put more of
: anything in a container, the whole system (i.e. container + anything) would
: weigh more Right. So why compress it?
Uh, check your physics. The air in the tubes does weigh something.
The air has mass, which is acted on by gravity, hence weight.
But before I go to far, the difference would be slight. Probably not
worth the effort. A good meaure would be pump up your wheel to
~45 pounds (high MTB pressure). The wheel now contains 4 ATM of air pressure
(3 ATM above regular air pressure). Weigh the wheel.
Mass of a gas is directly proportional to pressure (assuming
constant temp). Now let out all the pressure. It now has 1 ATM of
air. (even if flat, it is displacing less, so the effect would be the
same.) Weigh again. This would be about the same as going from
Air (N2 and O2) to helium (He2). Let us know what you find.
: My suggestion is to make a bike that is vacuum in the tubes. Nothing weights
: less then something. Right? So make everything on the bike hollow and remove
: the air from inside it. This would make my bike lighter then your helium or
: hydrogen bike by a whole microgram. I could blow past you up a hill any day.
: But would it be because I bike about 200 miles a week or would it be the weight
I grew up near ISU. What are you refering to as a hill? Be careful of
poking fun on the net. Their is always someone to poke back :)
--
Thanks,
Mike
David M. McBride
were serious or not. So here goes. Cost to weight ratio, dangerous, and just
plain wouldn't matter greater scheme of things.
would have weight but since you are confined to the earth no weight. And how
much more would it cost to seal the whole bike, I believe a lot more, for what
a microgram of weight savings. Sorry I will just stick with my Ti bolts and
nuts.
2nd The use of hydrogen in a bike tube would be like riding the Hindenburg
(sp?). One small frame crack and spark and you would need a tube to piss out
of because (well you know).
3rd Compressing the gas will not make it any lighter. I f you put more of
anything in a container, the whole system (i.e. container + anything) would
weigh more Right. So why compress it?
My suggestion is to make a bike that is vacuum in the tubes. Nothing weights
less then something. Right? So make everything on the bike hollow and remove
the air from inside it. This would make my bike lighter then your helium or
hydrogen bike by a whole microgram. I could blow past you up a hill any day.
But would it be because I bike about 200 miles a week or would it be the weight
difference.
That was fun.
TheEverlast
Arun Sankaran (ar...@u.washington.edu) wrote:
: Hello,
: I was just pondering about a way to make bikes lighter that seems
: very simple to me. Since frames are usually hollow tubing why not seal
: the ends and fill them with lighter-that-air gases like helium or
: hydrogen. Same goes for the tires. If they were constructed with slightly
: different materials they could probably hold these gases in a
: preassurized state. Why is this not done? (or is it?)
: Comments/Suggestions welcome.
: -Arun
Robert Horvatich
> Hello,
> I was just pondering about a way to make bikes lighter that seems
> very simple to me. Since frames are usually hollow tubing why not seal
> the ends and fill them with lighter-that-air gases like helium or
> hydrogen. Same goes for the tires. If they were constructed with slightly
> different materials they could probably hold these gases in a
> preassurized state. Why is this not done? (or is it?)
> Comments/Suggestions welcome.
>
> -Arun
Instead of replacing the air inside the tubes with something that is
lighter than air but heavier than nothing, why don't you just put nothing
in there (a vacuum).
Both hydrogen and helium require very good seals to contain. Hydrogen
has a nasty way of reacting the materials like steel causing them to
become brittle. I guess if you feel silly, you could such the helium out of
your frame and talk funny.
The mass of air inside your frame is not a significant magnitude. You
could probably lose as much weight by spitting before you ride.
email: |"You can't take life too seriously,
rho...@tbd.ford.com | you don't get out alive." Bugs Bunny
ig...@gate.net
> Hello,
> I was just pondering about a way to make bikes lighter that seems
> very simple to me. Since frames are usually hollow tubing why not seal
> the ends and fill them with lighter-that-air gases like helium or
> hydrogen. Same goes for the tires. If they were constructed with slightly
> different materials they could probably hold these gases in a
> preassurized state. Why is this not done? (or is it?)
> Comments/Suggestions welcome.
>
> -Arun
It was tested a few years ago. I saw an article in American Bicyclist about it. It seems there was a slight
problem with the unattended bikes floating away and becoming a serious threat to air transportaion safety.
Tethering the bikes to sandbags was tried but in the end it was determined that suitable mooring couldn't
always be relied upon. The idea was put on the back burner until a more suitable and portable ballast
could be designed.
Jim
David M. McBride
: David M. McBride (dmm...@rs6000.cmp.ilstu.edu) wrote:
: : 1st. The air in the tubes now don't weight anything and its free. In a vacuu
m it
: : would have weight but since you are confined to the earth no weight. And how
: : much more would it cost to seal the whole bike, I believe a lot more, for wh
at
: : a microgram of weight savings. Sorry I will just stick with my Ti bolts and
: : nuts.
: : 2nd The use of hydrogen in a bike tube would be like riding the Hindenburg
: : (sp?). One small frame crack and spark and you would need a tube to piss ou
t
: : of because (well you know).
: : 3rd Compressing the gas will not make it any lighter. I f you put more of
: : anything in a container, the whole system (i.e. container + anything) would
: : weigh more Right. So why compress it?
: Uh, check your physics. The air in the tubes does weigh something.
: The air has mass, which is acted on by gravity, hence weight.
Weigh a kilogram of water on land then in your bath tub. I didn't say the gas
did not have mass I said it had no wieght. Back to the water, it would have the
same mass above and below the water but different weights
: But before I go to far, the difference would be slight. Probably not
: worth the effort. A good meaure would be pump up your wheel to
: ~45 pounds (high MTB pressure). The wheel now contains 4 ATM of air pressure
: (3 ATM above regular air pressure). Weigh the wheel.
: Mass of a gas is directly proportional to pressure (assuming
: constant temp). Now let out all the pressure. It now has 1 ATM of
: air. (even if flat, it is displacing less, so the effect would be the
: same.) Weigh again. This would be about the same as going from
: Air (N2 and O2) to helium (He2). Let us know what you find.
: : My suggestion is to make a bike that is vacuum in the tubes. Nothing weights
: : less then something. Right? So make everything on the bike hollow and remove
: : the air from inside it. This would make my bike lighter then your helium or
: : hydrogen bike by a whole microgram. I could blow past you up a hill any day.
: : But would it be because I bike about 200 miles a week or would it be the wei
ght
: I grew up near ISU. What are you refering to as a hill? Be careful of
: poking fun on the net. Their is always someone to poke back :)
My driveway has a 35 degree slope. Theres hills around here you just have to
look.
: --
: Thanks,
: Mike
John Hunt
Hydrogen is potentially explosive which pretty much rules out its use for
anything so casual as filling your tires. I'm not a metalurgist so I will
defer to anyone with superior knowledge on the next point. I do know that
there is something called hydrogen embrittlement, where hydrogen atoms
diffuse into the crystaline structures of metal, drastically reducing
their strength, so that may point to a potential no-no for filling frames
with it.
As for filling your tires with helium, have you ever tried to keep a
helium baloon inflated? It is nearly impossible because helium readily
diffuses out through the rubber baloon membrane. I would assume a similar
problem would exist with tires. As for filling frames I don't think there
is so much volume inside frames that the change in density of the
intertubal gas would have that much effect on the weight of the frame. I
don't have the reference books with me to be able to figure out the
difference. Still, for race day it might make sense to fill the tires
with helium, especially since the mass is roatating. Quicker
acceleration? Who has the tables handy?
If you wanted to lighten a frame, sealing it with a vacuum inside would
save more weight than either gas. It might be a problen on some of the
large diameter, thin wall tubes used these days.
However, perhaps a way to make an ultralight frame would be to use large
diameter, very thin wall tubing and then pressurize the frame. The
pressure in the frame would increase the buckle strength of the tube by
preventing the wall of the tube from buckling, it is stretched tight.
If you want to see and example, shake up a can of Coke and try to crumple
it, then crumple it empty. Since there is some gas volume in the can, it
is the gas pressure that is preventing the can from crumpling. This has
two very obvious drawbacks.
1) If the frame became unpressurized it would collapse like an
empty soda can.
2) If the tube weakened to the point that it failed under
pressure, I sure wouldn't want it between *MY* legs! ;^)
A very interesting question though, one I have wondered about myself.
Hopefully somebody can add some hard numbers to this discussion.
-John-
Arun Sankaran (ar...@u.washington.edu) wrote:
: Hello,
Arun Sankaran
I agree with the two most popular responses:
1) A vacuum is lighter than helium/hydrogen (should have known this)
2) Weight reduction would be so insignificant that it's not worth
the trouble.
I guess it seemed too simple and easy to be true. Oh well. Thanks
everyone for all your really interesting comments. Keep 'em coming.
" We are Pentium of Borg " =================
" Division is Futile " | Arun Sankaran |
" You will be approximated " =================
Mike DeMicco
enclosed volume (e.g. weld 2 stamped sheet metal shells together), then
filled that space with helium...
You'd have to do some buoyancy calculations to see if it would be worthwhile.
--
Mike DeMicco <demi...@llnl.gov>
Kurt Lorentz Munson
> The air has mass, which is acted on by gravity, hence weight.
> worth the effort. A good meaure would be pump up your wheel to
> ~45 pounds (high MTB pressure). The wheel now contains 4 ATM of air pressure
> (3 ATM above regular air pressure). Weigh the wheel.
Yes, air does weigh something, but considering that most of us r.b.o.
folks ride on the earth in the presence of an atmosphere, by Archimedes
principle the air will weigh nothing. Hence filling anything with helium
will theoretically decrease its weight when used in an
oxygen/nitrogen/etc environment such as ours. However, what makes this
thread a true exercise in banality is how little weight difference would
be realized. Some back of the envelope calculations show that the
difference would be on the order of micrograms (sorry, no hard numbers
without a calculator). This just goes to show how low the density of a
gas is compared to steel, al, etc.
>
> I grew up near ISU. What are you refering to as a hill? Be careful of
> poking fun on the net. Their is always someone to poke back :)
>
I did as well. I once heard that there was a hill 35 miles NW of Ames,
but this was never verified 8). Prolly just some sort of pig pile or hay
bail tho....
-kurt
jen
more than in their natural state,, thus increaasing rather than
lightening the load...
go figure.......
Joe Moche
Arun Sankaran <ar...@u.washington.edu> writes:
>
>Hello,
> I was just pondering about a way to make bikes lighter that seems
>very simple to me. Since frames are usually hollow tubing why not seal
>the ends and fill them with lighter-that-air gases like helium or
>hydrogen. <snip>
When you pump your bike and tires with hydrogen, be sure to get some of
those cool stickers that say "No Smoking Within 50 Feet"!
--Joe
Toby Lovern
> My suggestion is to make a bike that is vacuum in the tubes. Nothing
weights
> less then something.
> That was fun.
> TheEverlast
>
> <<<< tobes writes >>> Maybe this idea isn't completely stoopid. If you
had a frame with really thin tubes I guess that you could ( theoretically
) use a high pressure gas to strengthen the tube from the inside and stop it
failing in a high stress environment . This would probably be completely
impossible in the real world but is an interesting idea. I read a post from
Keith Bontrager in this group yonks ago, If your'e reading this Keith ,what
about giving us some words of wisdom from someone who knows what he's
talking about.........
>
--
*****************************************************************
* Toby Lovern *"if I was adrift at sea with a *
* * dead chick; I'd probably kiss her"*
* to...@lardboy.demon.co.uk * -Beavis & Butthead. *
* llul...@reading.ac.uk * *
*****************************************************************
* all spelling mistakes are intentional. probably. *
*****************************************************************
Dean Hickman
>Hello,
> I was just pondering about a way to make bikes lighter that seems
>very simple to me. Since frames are usually hollow tubing why not seal
>the ends and fill them with lighter-that-air gases like helium or
>hydrogen. Same goes for the tires. If they were constructed with slightly
>different materials they could probably hold these gases in a
>preassurized state. Why is this not done? (or is it?)
>Comments/Suggestions welcome.
>-Arun
Not to be a downer...But everyones suggestions about vacuums and
alternative gasses suck...All that extra weight in seals and shit
would be self defeating...Now the thing to do is make the bike more
araeted...You know...More holes...Anyways...I've heard of frames like
this...With holes placed in certain areas on the bike that wouldn't
affect strength and handling...One problem with that also...There
aren't many "wasted " areas on a bike frame...it's not as though
companies are using any unecessary materials...also...Try putting a
vacum inside a bike...Ok...then put a minor dent in
it...floosh...imploseion...it would suck together...it might not be
right away...but it would happen over time and be a major week
point...And it's easy to dent an aluminum frame...but if you were to
close off the tubes and have seperate air chambers and shit it would
end up weighing more then before...Anywas...the air inside the bike
doesn't weigh anything...it's not like we'd notice that AIR
considering we are in an environment flooded by thousands of tons of
AIR...sorry man...thanx for coming out...
LAMAr...
James E. Snook
racing?? If you use Xenon in your tubes you can start to see weight
differences in the range of 20-30 grams. Radon would be dangerous,not
explosive like Hydrogen but an alpha emitter (no matter which isotope
you pick).
I don't know, I thought it was one of those discussions that falls into
the category of interesting but useless. A nice break from the usual
mtb'ers vs. vandeman crap.
Warren Block
: Hello,
: I was just pondering about a way to make bikes lighter that seems
: very simple to me. Since frames are usually hollow tubing why not seal
: the ends and fill them with lighter-that-air gases like helium or
: hydrogen. Same goes for the tires. If they were constructed with slightly
: different materials they could probably hold these gases in a
: preassurized state. Why is this not done? (or is it?)
: Comments/Suggestions welcome.
Well, it's not so much the weight of the bike as its mass. Weight is
pull towards the center of the earth; mass is what keeps you from
instantly accelerating or decellerating.
Now, helium or hydrogen have less mass than air, true, but it's probably
not enough to be noticeable. As one snide comment indicated, vacuum
would be better, but still probably not enough better to be worth it.
For a big improvement, get lighter (that is, less mass) wheels, since
their spinning mass is a big part of how quick a bike feels.
--
.----------------------------------------------------------------.
| Warren R. Block * New EMail Address: wbl...@rapidnet.com |
| Rapid City SD USA * Brought to you in majestic INEMASCOP! |
`----------------------------------------------------------------'
Marshall Hance
>the air inside the bike
>doesn't weigh anything...it's not like we'd notice that AIR
>considering we are in an environment flooded by thousands of tons of
>AIR...sorry man...thanx for coming out...
Sure doesnt weigh anything, but what if you could replace the air with
something of negative weight?
--------------------
MЧH
--------------------
Tom Lichy
>Hello,
> I was just pondering about a way to make bikes lighter that seems
>very simple to me. Since frames are usually hollow tubing why not seal
>the ends and fill them with lighter-that-air gases like helium or
>hydrogen. Same goes for the tires. If they were constructed with slightly
>different materials they could probably hold these gases in a
>preassurized state. Why is this not done? (or is it?)
>Comments/Suggestions welcome.
THis is a pretty old question which pops up here every year.
Filling a bike with hydrogen won't really make any difference to the
weight, BUT there are other things you can do with gas and a frame.
To illustrate, take a 2-litre plastic Coke bottle, full of
Coke. Put it on the ground. Now jump on it. Yup, really hard.
And it won't burst. Damn strong isn't it? That's cos
of the internal pressure reinforcing the plastic, a well
known engineering principle. Empty/drink the Coke, take
the cap off, and see how weak the plastic is normally.
But wouldn't filling a bike frame with even a lightweight fluid
be pretty heavy? Yup, but now put the cap back
on the empty coke bottle, and try jumping on it as hard as you can.
Hit it with a sledgehammer. Indestructable isn't it?
So why not do the same with bike frames - seal them and
fill them with compressed air at high pressures? Due to fears
over leaks and stuff, the bike frame would probably need to
be repaced every year, at least until it was known how durable
they were, but the pro's do this anyway.
A compressed air frame would be much lighter cos the tube walls
could be made much thinner and still maintain the neccessary
rigidity and dent-proof-ness.
And no, I dunno why this hasn't been done yet.
Tom Lichy, Department of Artificial Intelligence. <disclaimer>
t...@dcs.ed.ac.uk University of Edinburgh. <goes here.>
Cannondale and Yeti, both with Mavic gruppo. Both now stolen :( :( :(
-----------------------------------------------------------------------------
Gary Wood
>
>Hello,
> I was just pondering about a way to make bikes lighter that seems
>very simple to me. Since frames are usually hollow tubing why not seal
>the ends and fill them with lighter-that-air gases like helium or
>hydrogen. Same goes for the tires. If they were constructed with slightly
>different materials they could probably hold these gases in a
>preassurized state. Why is this not done? (or is it?)
>Comments/Suggestions welcome.
>
>
Pay no attention to the other responses, Arun. They simply are envious of
your greater imagination and technical prowess...
_I_ understand your real reason for wanting a hydrogen filled frame!!!!
Add a simple valve near the rear fork covered with a spring loaded
scratch wheel (a la Zippo lighter...), and you can easily flame the
next Yahoo that dares try to take you on a downhill singletrack ! Not
to mention the afterburner effect from said blaze !
Ingenious !!! No doubt it will be part of world cup events from here
on in...
Robert Horvatich
> vacum inside a bike...Ok...then put a minor dent in
> it...floosh...imploseion...it would suck together...it might not be
> right away...but it would happen over time and be a major week
> point...And it's easy to dent an aluminum frame...but if you were to
> close off the tubes and have seperate air chambers and shit it would
> end up weighing more then before...Anywas...the air inside the bike
> doesn't weigh anything...it's not like we'd notice that AIR
> considering we are in an environment flooded by thousands of tons of
> AIR...sorry man...thanx for coming out...
I agree with your statement on the added weight of valves and seals bit.
The mass of air removed would weigh less than the internals of a schrader
valve.
I don't agree with the implosion bit. If you were able to pull a perfect
vacuum, the difference in pressure would be only around 14 psi. I think
one would need a bit more than that to initiate yielding in an tube similar
to that of a bicycle tube.
Rob
Arun Sankaran
Many of you are skeptical about the feasibility of gas or vacuum
filled frames (and have damn good arguments for it too.) Some of
you said that the reason was due to limitations on the metals available
today. You guys might be interested in reading the following segment from
Popular Mechanics, Oct. 95 Vol 1/2 No. 10, p.24.
" Keep an eye out for beryllium. Element 4 on the
periodic table is the latest (and possible the last) exotic structural
material to hop from military to commercial applications. Much lighter
and stronger than titanium, beryllium combines resiliency and
stiffness--two traits usually considered mutually exclusive. "
The caption on the picture talks about "beryllium's inherent
vibration-dampening property." Sound interesting?
Arun Sankaran
> dban...@direct.ca (Dean Hickman) wrote:
> >the air inside the bike
> >doesn't weigh anything...it's not like we'd notice that AIR
> >considering we are in an environment flooded by thousands of tons of
> >AIR...sorry man...thanx for coming out...
>
> Sure doesnt weigh anything, but what if you could replace the air with
> something of negative weight?
>
This is where I was also confused. Here is another question (perhaps
better suited for a physics newsgroup.) If you had two rigid, massless
containers, one filled with helium and the other in a vacuum which would
provide more lifting power. (that's the best I can describe it) I always
think of helium as having "negative weight" or the ability to lift or
reduce the weight of the vessel it's contained in. On the other hand, a
vacuum is a void and it's difficult to visualize it's reaction to air.
(unfortunately you cannot fill a balloon with vacuum and see if it
floats). But I do understand the concept that "nothing (vacuum) is lighter
than something (helium)." Good thing I am not a physics major huh. =)
Bartholomew S. Blair
>
>This is where I was also confused. Here is another question (perhaps
>better suited for a physics newsgroup.) If you had two rigid, massless
>containers, one filled with helium and the other in a vacuum which would
>provide more lifting power. (that's the best I can describe it) I
always
>think of helium as having "negative weight" or the ability to lift or
>reduce the weight of the vessel it's contained in. On the other hand,
a
>vacuum is a void and it's difficult to visualize it's reaction to air.
>(unfortunately you cannot fill a balloon with vacuum and see if it
>floats). But I do understand the concept that "nothing (vacuum) is
lighter
>than something (helium)." Good thing I am not a physics major huh. =)
>
It is very simple, The true vacuum has no mass, while the
hydrogen/helium is
"lighter than air". This means that in our atmosphere, the
hydrogen/helium
has "negative wieght, if that is how you want to think about it. A
perfect
example is the 18 wheelers you see on the interstate. Keep your eyes
open
for truck carrying these gases. Often, on a downhill run, if you look
closely
enough, you will see that the wheels really aren't turning at full
speed.
That is because the trailer is actually being lifted off the ground by
the
gas stored inside. I know several truckers and they say that they get
much
better mileage when carrying these gases.
Bart
Kurt Lorentz Munson
> Hi all,
> Many of you are skeptical about the feasibility of gas or vacuum
> filled frames (and have damn good arguments for it too.) Some of
> you said that the reason was due to limitations on the metals available
> today.
Time to repeat the bottom line again: weight savings would be in the
range of a few micrograms. A great reason to be skeptical, at least in
my book.
> You guys might be interested in reading the following segment from
> Popular Mechanics, Oct. 95 Vol 1/2 No. 10, p.24.
>
> " Keep an eye out for beryllium. Element 4 on the
> periodic table is the latest (and possible the last) exotic structural
> material to hop from military to commercial applications. Much lighter
> and stronger than titanium, beryllium combines resiliency and
> stiffness--two traits usually considered mutually exclusive. "
>
> The caption on the picture talks about "beryllium's inherent
> vibration-dampening property." Sound interesting?
Yes, it sure sounds interesting. Too bad the drawbacks weren't mentioned
tho....
Drawbacks like beryllium being very toxic. Couple this with the fact
that nearly all beryllium parts are made by powder metallurgy
(compressing and sintering a fine powder in a mold) and the result is a
nice toxic dust cloud waiting to be inhaled. Thus OSHA decides
that the production costs are going to be <very> high indeed, or the
production facility moves to a remote third world location.
A dream bike on paper, tho....
-kurt
Kristan Roberge
>
> Hi all,
> Many of you are skeptical about the feasibility of gas or vacuum
> filled frames (and have damn good arguments for it too.) Some of
> you said that the reason was due to limitations on the metals available
>
> " Keep an eye out for beryllium. Element 4 on the
> periodic table is the latest (and possible the last) exotic structural
> material to hop from military to commercial applications. Much lighter
> and stronger than titanium, beryllium combines resiliency and
> stiffness--two traits usually considered mutually exclusive. "
I can tell your new to bicycling. Beryllium is old-news. American
Bicycles had a limited series of bonded Beryllium frames 4 years ago.
They weighed 2.5 pounds and 1.5 pounds of that were the aluminum lugs
and the epoxy. It was suggested at the time, that a TIG welded Be frame
would weigh about 1 pound. PM magazine is once again, behind in the
times.
Oh, the limited series of frames were a total of 4. They cost $23,000
to $25,000 US EACH. That's just the frame. That's what you get for
a prototype showbike. One was sold to a Major Taiwanese Trading
Company (its in their lobby), and one of them (#4 I think) was stolen
out of American's wharehouse a year or so ago (good luck for the thief
trying to sell that thing - go ahead, alter the serial number... we
know its stolen)..
BeYond Beryllium's frame is using a welded Be frame made in a russian
factory where they used to make missile parts. The tubing is coming
a mix of new alloy as well as recycled tubing from ICBMs.
James E. Snook
>Well, the reason it isn't done is the cost of the gases, plus the fact
>that hydrogen is volatile.
Whoa...hold on here. Hydrogen is not only a gas but is also volatile!
Which gasses aren't volatile? Maybe r.b.o's resident physics
experts can tell us.
"Why do you keep using that word. I don't think it means what you
think it means." --Enigo Montoya
James E. Snook
>
>true, that would remove the micrograms of weight of the air, but helium
>would not only be lighter, but would also provide some lift to reduce
>the effective weight of the bike (part of it is being supported by the
>helium).
Hmmm, and all along I always thought it was the air around a baloon that
made it bouyant and the helium inside served to hold the baloon's shape
and lower the ratio of the weight of the baloon to the air displaced.
I am glad this has been straightened out.
d kopf
>" Keep an eye out for beryllium. Element 4 on the
>periodic table is the latest (and possible the last) exotic structural
>material to hop from military to commercial applications. Much lighter
>and stronger than titanium, beryllium combines resiliency and
>stiffness--two traits usually considered mutually exclusive. "
>
>The caption on the picture talks about "beryllium's inherent
>vibration-dampening property." Sound interesting?
>
well you know american cycles had a $25000 beryllium bike made a few
years back. i think i will wait for the price to come down a bit.
d kopf
colorado springs
Art Delano
<Pine.A32.3.91j.950915...@homer12.u.washington.edu>,
Arun Sankaran <ar...@u.washington.edu> wrote:
] Many of you are skeptical about the feasibility of gas or vacuum
] filled frames (and have damn good arguments for it too.) Some of
] you said that the reason was due to limitations on the metals available
] today. You guys might be interested in reading the following segment from
] Popular Mechanics, Oct. 95 Vol 1/2 No. 10, p.24.
]
] " Keep an eye out for beryllium. Element 4 on the
] periodic table is the latest (and possible the last) exotic structural
] material to hop from military to commercial applications. Much lighter
] and stronger than titanium, beryllium combines resiliency and
] stiffness--two traits usually considered mutually exclusive. "
American Bicycles (they usually make aluminum frames) made a prototype
beryllium frame a few years ago. cost $25,000. save your pennies and cash
in your Merlin.
AjD
--
ade...@frymulti.com http://www.frymulti.com/~adelano/
Tom spins the foot.
John Hunt
>>SNIP<<
: So why not do the same with bike frames - seal them and
: And no, I dunno why this hasn't been done yet.
Probably the fear of that thin-wall, high pressure vessel failing and
throwing shrapnel into some rider's private parts! ;^)
-John-
Thomas J. Stout
: Hi all,
: Many of you are skeptical about the feasibility of gas or vacuum
: you said that the reason was due to limitations on the metals available
: today. You guys might be interested in reading the following segment from
: Popular Mechanics, Oct. 95 Vol 1/2 No. 10, p.24.
:
: " Keep an eye out for beryllium. Element 4 on the
: periodic table is the latest (and possible the last) exotic structural
: material to hop from military to commercial applications. Much lighter
: and stronger than titanium, beryllium combines resiliency and
: stiffness--two traits usually considered mutually exclusive. "
: The caption on the picture talks about "beryllium's inherent
: vibration-dampening property." Sound interesting?
:
: " We are Pentium of Borg " =================
: " Division is Futile " | Arun Sankaran |
: " You will be approximated " =================
Of course there is that tiny little issue of toxicity....
Be metal is fine, as is, but the DUST on the otherhand....
-Tom
--
--------------------------------------------------------------------------
Thomas J. Stout st...@msg.ucsf.edu
Box 0448 Department of Biochemistry st...@neptune.ucsf.edu
School of Medicine st...@brok.ucsf.edu
University of California, San Francisco (415) 476-3937
San Francisco, CA 94143-0448 (415) 476-1902 FAX
--------------------------------------------------------------------------
John Hunt
Anybody else know about that?
Robert Zitka
between road and tire has a large influence. By reducing the rolling
friction of the tire, it would make it easier to go forward.
Generally, the narrow tires on road bikes give better results than the
wide and grippy tires on mountain bikes.
Also, wind resistance becomes appreciable at higher speeds. Another force
to overcome.
Rob
Robert Zitka
: Arun Sankaran (ar...@u.washington.edu) wrote:
: : Hello,
: : I was just pondering about a way to make bikes lighter that seems
: : very simple to me. Since frames are usually hollow tubing why not seal
: : the ends and fill them with lighter-that-air gases like helium or
: : hydrogen. Same goes for the tires. If they were constructed with slightly
: : different materials they could probably hold these gases in a
: : preassurized state. Why is this not done? (or is it?)
: : Comments/Suggestions welcome.
: Well, it's not so much the weight of the bike as its mass. Weight is
: pull towards the center of the earth; mass is what keeps you from
: instantly accelerating or decellerating.
: Now, helium or hydrogen have less mass than air, true, but it's probably
: not enough to be noticeable. As one snide comment indicated, vacuum
: would be better, but still probably not enough better to be worth it.
: For a big improvement, get lighter (that is, less mass) wheels, since
: their spinning mass is a big part of how quick a bike feels.
Well, lighter weels may provide better acceleration. But, heavier wheels
have better momentum (ie, it acts like a flywheel). The higher energy
stored in the wheels helps push the bike when not pedaling. To what
degree this works could be calculated.
: --
Arun Sankaran
Alright. Does nothing get by you guys. Geez, I had about 20 peopel say
that Be is toxic and it's been around for couple of years. Why didn't
Popular Mechanics tell me this to save me from looking stupid. Was this
new to anyone out there? Tell me that I wasn't the only one. Please. ;}
Kristan Roberge
Johnson-Barbier
>I deem to recall something about (berrylium) being very poisonous.
>Anybody else know about that?
>
Be is toxic to a small portion of people (I've read numbers of 5 percent
to 20 pecent of the population. It appears that the level of toxicity
varies from person to person.
The berrylium dust is the problem -- it should (theory) only affect those
who work and grind the metal.
--
Mark Johnson-Barbier
http://linus.cs.ohiou.edu/~johnsonm/index.html
john...@linus.cs.ohiou.edu
Joshua P. Weage
: Hi all,
: Many of you are skeptical about the feasibility of gas or vacuum
: filled frames (and have damn good arguments for it too.) Some of
: you said that the reason was due to limitations on the metals available
: today. You guys might be interested in reading the following segment from
: Popular Mechanics, Oct. 95 Vol 1/2 No. 10, p.24.
:
: " Keep an eye out for beryllium. Element 4 on the
: periodic table is the latest (and possible the last) exotic structural
: material to hop from military to commercial applications. Much lighter
: and stronger than titanium, beryllium combines resiliency and
: stiffness--two traits usually considered mutually exclusive. "
: The caption on the picture talks about "beryllium's inherent
: vibration-dampening property." Sound interesting?
:
Except for the fact that beryllium is very rare
and highly toxic, it would be great.
Josh
--
----------------------------------------------------------------
-- Joshua Weage E-Mail : we...@mtu.edu --
-- Third Year ME Student & CAEL Partner --
-- Check out my homepage @ http://www.me.mtu.edu/~weage/ --
-- "Together we will rule the universe, all by myself" --
-- -- Tom Servo Mystery Science Theater 3000 --
Robert Zitka
: zi...@interactive.net (Robert Zitka) wrote:
: >You know, it's not so much the weight of the bike either. The friction
: >Rob
: Where talking actual measurable weight...Measurable by upward
: force...your talking horizontal resistance...
Sure, i understand that. But the original poster is talking about making
a bike lighter. And the assumption, is that a lighter bike will be faster
and easier to ride for longer distances. If you decrease rolling
resistance and wind resistance, it will also achieve the same desired
affects of faster and longer riding.
Instead of fooling around with helium, let's eliminate larger causes of
resistance.
Robert Horvatich
>
> But HELIUM does NOT weigh in at NOTHING...It weaighs something...Cause
> the helium gas has like 1
> electon in it's atom...something like that...and electrons are what
> provide the weight...
I think you should consult a physics book. I can assure you that the
mass of an electon makes up only a small fraction of the entire mass of
an atom. I also think that if you start worrying about the weight of
your bike in terms of the mass of electrons in it, you need to get out
and ride more.
Robert Horvatich
> compressed...so it's heavier...but yet it lifts...ok...have you ever
> lifted a tank of helium...they weight the same full as they do
> empty...
Are you sure about that. How accurate was the scale that you where using.
If you are talking about lifting it up with your hand, your scale (hand)
is most likely at fault. They will weigh different amounts. The mass
of the container is many orders of magnitude greater than that contained
within. The difference is very small indeed. So small that I doubt
that by just lifting it up that you would be able to detect it.
Michael Fuhrer
made of Be-Cu, and I've personally made low-temperature springs out of Be-Cu).
The danger of toxicity of working with this alloy is similar to that of pure
Beryllium, and if you take precautions, is No Big Deal.
I'm sure the reasons for whether or not we'll see Be bikes on the market will
have a lot more to do with its availability, and the ability to draw it into
tubes. (Can you butt this stuff?)
Michael Fuhrer
Arun Sankaran
>
> Robert Horvatich <rhorvat@tbd140> wrote:
>
> >On Sun, 17 Sep 1995, LAMAr wrote:
> >>
> >> But HELIUM does NOT weigh in at NOTHING...It weaighs something...Cause
> >> the helium gas has like 1
> >> electon in it's atom...something like that...and electrons are what
> >> provide the weight...
>
> >I think you should consult a physics book. I can assure you that the
> >mass of an electon makes up only a small fraction of the entire mass of
> >an atom. I also think that if you start worrying about the weight of
> >your bike in terms of the mass of electrons in it, you need to get out
> >and ride more.
>
> >Rob
>
> Hey fuck you...it was the other guy that was talking about the weight
> of the gas inside his fucking bike...that's lame...And I said it
> was...I'm not some weight freak anal loser...I know that having gas in
> yer bike if it made any difference at all would be negative
> differences like top heaviness...So back off and go ride yer bike
> loser...
>
> LAMAr...
> Someone's gotta be the asshole, You should thank me for taking on the responability...
>
Alright everyone. I am the one that made the original post. Call me
stupid, ignorant, whatever, but this has gone on long enough. Move on to
something else. It was just an idea that I was curious about. It wasn't
meant to take over the newsgroup. LEAVE THIS THREAD ALONE. IT IS DEAD. RIP.
BTW. ANy one hear anything about Scott shocks. Are they any goof?
Arun Sankaran
> be put to an end...some people are beating a dead horse here...
>
>
You said it.
LAMAr
>> But that doesn't make sence...cause the gas is pressurized...so it's
>> compressed...so it's heavier...but yet it lifts...ok...have you ever
>> lifted a tank of helium...they weight the same full as they do
>> empty...
>Are you sure about that. How accurate was the scale that you where using.
>If you are talking about lifting it up with your hand, your scale (hand)
>is most likely at fault. They will weigh different amounts. The mass
>of the container is many orders of magnitude greater than that contained
>within. The difference is very small indeed. So small that I doubt
>that by just lifting it up that you would be able to detect it.
>Rob
YA...But that's in an entire tank of helium...So MAybe there was a
difference that I couldn't notice...O'well...were trying to come up
with noticable differences in a bike...I think this gas thing should
be put to an end...some people are beating a dead horse here...
LAMAr...
Peter D. Engels
<Pine.A32.3.91j.950915...@homer12.u.washington.edu>,
Arun Sankaran <ar...@u.washington.edu> wrote:
> periodic table is the latest (and possible the last) exotic structural
> material to hop from military to commercial applications. Much lighter
> and stronger than titanium, beryllium combines resiliency and
> stiffness--two traits usually considered mutually exclusive. "
Its definitely something you want to keep an eye out for - and avoid.
Beryllium oxide - the oxidized form of the pure metal - is a nasty
poison. Its not a material to use casually.
--
Pete
Bartholomew S. Blair
>>Rob
>
>Hey fuck you...it was the other guy that was talking about the weight
>of the gas inside his fucking bike...that's lame...And I said it
>was...I'm not some weight freak anal loser...I know that having gas in
>yer bike if it made any difference at all would be negative
>differences like top heaviness...So back off and go ride yer bike
>loser...
>
> LAMAr...
>Someone's gotta be the asshole, You should thank me for taking on the
responability...
>
LAMAr, Thank you, everybody has to be good at something, keep this up
and you will be perfect in no time.
LAMAr
Robert Horvatich <rhorvat@tbd140> wrote:
>On Sun, 17 Sep 1995, LAMAr wrote:
>>
>> But HELIUM does NOT weigh in at NOTHING...It weaighs something...Cause
>> the helium gas has like 1
>> electon in it's atom...something like that...and electrons are what
>> provide the weight...
>I think you should consult a physics book. I can assure you that the
>mass of an electon makes up only a small fraction of the entire mass of
>an atom. I also think that if you start worrying about the weight of
>your bike in terms of the mass of electrons in it, you need to get out
>and ride more.
>Rob
Robert Glamm
>>> compressed...so it's heavier...but yet it lifts...ok...have you ever
>>> lifted a tank of helium...they weight the same full as they do
>>> empty...
>>Are you sure about that. How accurate was the scale that you where using.
>>If you are talking about lifting it up with your hand, your scale (hand)
>>is most likely at fault. They will weigh different amounts. The mass
>>of the container is many orders of magnitude greater than that contained
>>within. The difference is very small indeed. So small that I doubt
>>that by just lifting it up that you would be able to detect it.
>>Rob
>YA...But that's in an entire tank of helium...So MAybe there was a
>difference that I couldn't notice...O'well...were trying to come up
>with noticable differences in a bike...I think this gas thing should
>be put to an end...some people are beating a dead horse here...
Let's get the old Physics book out and that damned ideal gas law:
PV = nRT.
For filling a bike tire with a gas, you want P (pressure) and V (volume)
to be constant. T (temperature) is also constant, unless you live in
Minnesota where the temperature varies about 40 degrees/hour. R is the
gas constant, and doesn't change. Thus, since everything else is constant,
n must also be constant (n = number of moles).
So, using either Helium or air to fill your tires you will use the same
number of moles. Helium has an atomic weight of 4. Air has an atomic weight
of about 29, if I remember correctly (70% nitrogen, 20% oxygen -- remember,
these aren't lone N's and O's, these are N2's and O2's floating around).
Let's say for a mountain bike tire that's got a cross-sectional area of
4", and a 20" diameter tire, just for giggles. That's a total volume of
about 276.5 cubic inches, or about 4530.37 cm^3 = 4.53037 * 10^(-3) m^3.
P = 40 pounds/square inch for an idea tire. This is about 117.30 kg/cm^2, or
0.0117 kg/m^2.
T = 293 K (about room temperature).
For some reason, R = 8.31 * 10^(-5) sticks in my head, although I can't
remember the number offhand. So:
PV/RT = n = 2.18 * 10^(-3) moles.
Now, 1 mole of a gas weighs exactly it's atomic weight _in grams_. So,
the weight of helium in a tire = 8.7 _milligrams_, and the weight of air in
a tire is about 64.22 _milligrams_.
The other effect you need to consider is bouyancy. It doesn't make any
difference in either case. Air pressure is about 14psi, and in order for the
tire to be bouyant, it needs to be less pressurized than the air around it.
Which is moot, since tires are inflated to about 40psi anyway.
Thus -- it's pointless to fill either the frame or tires with helium.
-Bob
--
Bob Glamm | Email: gl...@mountains.ee.umn.edu
209 5th St. SE #207 | URL: http://www.cs.umn.edu/users/glamm/
Minneapolis, MN 55414 | EE grad, U of Minnesota - Twin Cities
(612)623-9437/(612)625-7876
Stephen Jay
retake physics. Helium won't make the machine noticeably lighter just more
bouyant.
It's the weight of the wheels, first and formost, then the frame that you
put your energy into moving. The old roadies' saying goes "a gram off the
wheels is worth 5 off the frame". This is because you not only have to
accellerate the wheel forward but around, too, to get moving. The frame
only has to be kept moving.
Spend big on wheels, spend big on frame, spend big on fancy lubes and
bearings and trick little titanium nuts, shave your legs, and shed fat
from your engine but save the lighter than air gasses for trackside.
They're more effective at psyching your opponents than making your bike
faster.
A.T.B.
--
Steve Jay - info...@postoffice.sandybay.utas.edu.au (steve jay)
Ride bikes, eat what you want, unlearn how to feel remorse and be happy BUT... :-/ .
Beaten paths are for beaten people and it's not that life is too short it's just that we're dead for such a long time.
Arun Sankaran
> On Tue, 19 Sep 1995, Arun Sankaran wrote:
>
> > Alright everyone. I am the one that made the original post. Call me
> > stupid, ignorant, whatever, but this has gone on long enough. Move on to
> > something else. It was just an idea that I was curious about. It wasn't
> > meant to take over the newsgroup. LEAVE THIS THREAD ALONE. IT IS DEAD. RIP.
> >
> > BTW. ANy one hear anything about Scott shocks. Are they any goof?
>
> I hear they ride really good if you pump them up with helium. :))
>
> Rob........I couldn't resist.
>
Alright wiseguy. Very funny. ;)
JRPRE...@news.delphi.com
weight of the bike.
But if you load up with hydrogen in the wheels and frame, you _could_
have an AWESOME explosion if you wiped out just right. :-)
Jim Ski
Bartholomew S. Blair
>to know about gas rationing during the oil crisis, so he skipped class
>to do a little doobage behind the girls' gym that day. And, even if
>that was not the topic of discussion, he figured he could still fart
>in public without getting caught.
>____
>
>I would offer a discussion on the whole bike/helium thing, but I am so
>disgusted with it that I'll leave it to the individual reader to apply
>the principles demonstrated in the story above.
>
>You seem to be a relatively bright bunch, with all exceptions
>previously noted.
>
>Auf weidersehen!
>
Bravo, what a way to end (hopefully) a discussion.
ASTFALCK ALLEN
>>>Rob
>PV = nRT.
sorry good till this point. bouyancy has nothing to do with pressure, just
density.
>Thus -- it's pointless to fill either the frame or tires with helium.
sorry, there is a point, a)decreases inertia
b)decreases wieght (not sure what wieght has to do with anything, when
its only really inertia that makes the difference
Derek Anderson
: Arun Sankaran <ar...@u.washington.edu> wrote:
: >" Keep an eye out for beryllium. Element 4 on the
: >periodic table is the latest (and possible the last) exotic structural
: >material to hop from military to commercial applications. Much lighter
: >and stronger than titanium, beryllium combines resiliency and
: >stiffness--two traits usually considered mutually exclusive. "
: >
: >The caption on the picture talks about "beryllium's inherent
: >vibration-dampening property." Sound interesting?
: >
: well you know american cycles had a $25000 beryllium bike made a few
: years back. i think i will wait for the price to come down a bit.
: d kopf
: colorado springs
It did, BE2 cycles has a frame for about $2000 that is made of a
beryllium metal matrix composite. BTW, Beryllium is VERY toxic, so don;t
lick your frame.
phyx...@zeus.kent.edu
>beryllium metal matrix composite. BTW, Beryllium is VERY toxic, so don;t
>lick your frame.
>
Note that Be is _not_ toxic, but Be _dust_ is. A slight difference.
Just make sure your frame's clean when you get it...
David Desoer
What I'm surprised no one has pointed out yet is the difficulty of
storing hydrogen in your tires in the first place. Hydrogen containes
only one proton, which means that it would sneak right through your valve
and even the smallest molecular hole in your tire (I don't know, but I
think it might go right through the tire). Secondly hydrogen, being so
small, works its molecules inbetween other materials molecules, causing
different results with different materials (it makes metals brittle, I
don't know what it would do to your tire). And of course, as everyone
and their uncle has pointed out it is explosive. So, even if you were
stupid enough to acually care about the minute change in weight you
couldn't actually store hydrogen. Besides, trimming your toenails and
fingernails would probably result in the same weight reduction.
And to stop the obvious replies:
Yes, I know the orrigional poster of the orrigional thread did it
as a joke.
No, I don't care about weight (I wear 10lb combats while cycling)
.----------------------------------.---------------------------------.
| David Desoer | Hamilton-Wentworth Freenet |
| da...@freenet.hamilton.on.ca | Information Committee |
|--------------------------------------------------------------------|
| Web Page - http://www.freenet.hamilton.on.ca/~ab170/Profile.html |
|____________________________________________________________________|
kent walker
>gl...@kittpeak.ee.umn.edu (Robert Glamm) writes:
>>>>Rob
>>PV = nRT.
all of which is made totally moot by the fact that if you inflated
your tires with helium, they'd be flat in a day. see, helium molecules
are small enough to pass through the pores in a rubber tube. if you
don't believe me, go buy a rubber balloon filled w/helium and see what
it looks like the next day.
Robert Zitka
: all of which is made totally moot by the fact that if you inflated
: your tires with helium, they'd be flat in a day. see, helium molecules
: are small enough to pass through the pores in a rubber tube. if you
: don't believe me, go buy a rubber balloon filled w/helium and see what
: it looks like the next day.
Well, just for clarification, but aren't baloons made of latex? I might
be wrong, but needed to add my 2 cents.
John Stevenson
ke...@eden.com (kent walker) wrote:
>helium molecules
>are small enough to pass through the pores in a rubber tube.
AAARGH! No they're bloody not. There's no such thing as a helium molecule.
It's a bloody inert gas, goes around as discrete atoms, which is why it
diffuses through membranes so readily.
John "Dunno why this annoys me so much, but it does" Stevenson
J M Flanagan
: In article <44pt0n$m...@boris.eden.com>,
: ke...@eden.com (kent walker) wrote:
Erm if you fill your wheels and frame with hydrogen you are a daft prat.
Hydrogen is one of the most combustable gases around, so I guess you'll
be up shit creek without any form of boyancy.
"Take no time to think.
Act on impulse."
Johnno.
sean
> In article <45besm$a...@newsbf02.news.aol.com>, cpo...@aol.com says...
> >
> >I hope someone has already made this point: adding helium to the frame
> >does NOT reduce the bike's mass. Thus even if the silly thing floated, it
> >would still be just as hard to move it forward, to turn it, to stop it....
> >
> >Nice try....
> >
> >-- Charlie Poling
Well actually.... It would drop the mass of the bike as you would be
replacing air with a gas of lower molecular mass, helium. Thus the total
mass of the bike, including space within the frame, would drop. That is,
of course, unless the bike frame interior is actually a vacuum... :)
Also, if the bike became too light<ie. the mass of the bike> it would be
very easy to turn the crank but it would be difficult to go anywhere as
you need friction to start, stop, and turn.
Sorry Charlie! :)
Sean
Char Tang
>
>I hope someone has already made this point: adding helium to the frame
>does NOT reduce the bike's mass. Thus even if the silly thing floated, it
>would still be just as hard to move it forward, to turn it, to stop it....
>
>Nice try....
>
>-- Charlie Poling
It wouldn't make a difference in performance, but it would be damn cool to have a
bike that floats in the air!!! ;)
Cpoling
Tom Andre Sj|lie
>I hope someone has already made this point: adding helium to the frame
>does NOT reduce the bike's mass. Thus even if the silly thing floated, it
>would still be just as hard to move it forward, to turn it, to stop it....
That is WRONG!!!
It WILL reduce the mass of the frame, although very little.
Can we end this discussion now?
Tom
Bartholomew S. Blair
>Also, if the bike became too light<ie. the mass of the bike> it would
be
>very easy to turn the crank but it would be difficult to go anywhere
as
>you need friction to start, stop, and turn.
>
>Sorry Charlie! :)
> Sean
>
I guess that that would be true if you were turning the cranks while
standing beside the bike. I may be full of something, but it isn't
helium, so I will rely on my 185 pounds to create the downforce that
will provide the friction to start, stop and turn.
Sorry Sean!
Bart
ADAM DAVID ROSENBLOOM
> In article <45besm$a...@newsbf02.news.aol.com>, cpo...@aol.com says...
> >
> >I hope someone has already made this point: adding helium to the frame
> >does NOT reduce the bike's mass. Thus even if the silly thing floated, it
> >would still be just as hard to move it forward, to turn it, to stop it....
> >
> >Nice try....
> >
> >-- Charlie Poling
>
> It wouldn't make a difference in performance, but it would be damn cool to have a
> bike that floats in the air!!! ;)
>
>
>Filling the frame with hydrogen would be dangerous. If the frame got
broken it would explode. Hydrogen does that. Helium filled tyres
wouldn't work because under the tire pressure would mean that the helium
would be heavier than air anyway.
>
>
>
Pete Hickey
Jollymon <da...@dean.dungeon.com> wrote:
>
>I think that *mass* is being confused with *weight* here. 1cc of
>aluminum weighs less than 1cc of iron, yet the mass is the same.
>Now if the helium causes the frame to shrink...
>
Oh my god!!! Everything I know is wrong!!!
Thanks!
-Pete
--
Pete Hickey | |
Communication Services | Pe...@mudhead.uottawa.CA | "Take off your shoes....
University of Ottawa | | .... for industry!"
Ottawa,Ont. Canada K1N 6N5| (613) 562-5800x1008 |
Randall Stone
returns would justify the investment. Air weighs around 30 grams per
mole (i.e. 22.4 liters at room temp and 14.7 psi). How much does a tire
hold, anyway? Assuming that about three liters of air would be replaced
(this would account for the higher pressure in the tires), that works out
to a weight savings of (3/22.4X30g=4g) 4 grams. That's about 4 cc of
water (1000 cc in a liter). Even taking into effect the mass-multiplying
effect of angular momentum in the tires, I don't think it will save much
effort.
Randall
Barry Logan
> >Filling the frame with hydrogen would be dangerous. If the frame got
> broken it would explode. Hydrogen does that. Helium filled tyres
> wouldn't work because under the tire pressure would mean that the helium
> would be heavier than air anyway.
> >
> >
> >
A. Hydrogen only explodes at fusion temperatures, otherwise it burns at a
controlled rate and is incapable of generating a shock front
characteristic of an explosion at atmospheric pressure, as gasoline etc.
can.
B. Helium filled tires would still have less mass than air filled tires
at the sames pressure, although less adiabatic (unresponsive to
temperature).
C. I calculate that the total mass savings would amount to less than the
dirt I collected on my last dusty ride, althought this hasn't stopped
some road racers from trying it.
It's fun to think about though.
------
Ray Schumacher blo...@crash.cts.com
Robert Horvatich
>
> >I hope someone has already made this point: adding helium to the frame
> >does NOT reduce the bike's mass. Thus even if the silly thing floated, it
> >would still be just as hard to move it forward, to turn it, to stop it....
>
> That is WRONG!!!
> It WILL reduce the mass of the frame, although very little.
The mass of the frame is actually increased a little bit with the
addition of more helium molecules (He2). You can not decrease the mass
of one material by adding the mass of another material to it.
>
> Can we end this discussion now?
Not until you get it right and pass the quiz. :)
> Tom
Rob
email: |"You can't take life too seriously,
rho...@tbd.ford.com | you don't get out alive." Bugs Bunny
Stephen P. Driska PhD
: >I hope someone has already made this point: adding helium to the frame
: >does NOT reduce the bike's mass. Thus even if the silly thing floated, it
: >would still be just as hard to move it forward, to turn it, to stop it....
<snip>
: Can we end this discussion now?
: Tom
No.
I suggest that all helium/hydrogen articles be forwarded to the equally-
long-running thread on the issue of whether a bike stored by being hung
by its rims from a hook will suffer deformed rims by the weight of the
bike. They're getting too serious with their arguments about spoke
tension and compression. Maybe the helium would lighten them up....
Steve Driska, Physiology Department, Temple University Medical School
Philadelphia, PA 19140 USA (215) 707-3283
dri...@astro.ocis.temple.edu
If I could think of something witty and clever to say, it would go right
here ----->> .........................
Tom Andre Sj|lie
answering..... :)
>The mass of the frame is actually increased a little bit with the
>addition of more helium molecules (He2). You can not decrease the mass
>of one material by adding the mass of another material to it.
Before filling my frame with helium, I have to remove all the oxygen
(which is heavier than helium) in it. Then it gets lighter..........
...but not much......
If you have a frame with helium in it, don't remove the seatpost!!
Tom Again
Appears Sane
> In article <45dtna$j...@hermod.uio.no> tsj...@math.uio.no (Tom Andre Sj|lie) writes:
> >From: tsj...@math.uio.no (Tom Andre Sj|lie)
> >Subject: Re: Helium/Hydrogen filled frame and tires.
> >Date: 10 Oct 1995 13:50:34 GMT
>
>
> >>I hope someone has already made this point: adding helium to the frame
> >>does NOT reduce the bike's mass. Thus even if the silly thing floated, it
> >>would still be just as hard to move it forward, to turn it, to stop it....
>
> >That is WRONG!!!
> >It WILL reduce the mass of the frame, although very little.
>
> >Can we end this discussion now?
>
>
> >Tom
>
> I think that *mass* is being confused with *weight* here. 1cc of
> aluminum weighs less than 1cc of iron, yet the mass is the same.
> Now if the helium causes the frame to shrink...
>
> Naw.
>
> -dave
>
Hello. I believe that the bike with Helium will indead weigh less than
the standard bike. It will also have less mass.
Weight is directly proportional to mass on Earth.
The air in our atmosphere is made up of approx. 80% nitrogen and 20
% oxygen. The molar mass of nitrogen is 14g and oxygen's is 16g. Both
of these components occur as a diatomic molecule, doubling the molar mass
for the molecule: N2=28 and O2=32
To avoid extended equations, this would give us a molar mass of between
these two numbers...closer to 28g as this makes up the bulk of it.
The molar mass of helium is approx. 4g. I am not sure how the helium we
buy compares to that, but I will assume it is close.
Molar mass is the mass of 6.022 x 10^23 units of what is being
measured. At standard pressure and temperature, a mole of any gas will have
the same volume. As we have seen in the above information, a mole of
"air" would have a markedly higher mass than helium in the same volume.
As mass and weight are directly proportionate on Earth, the weight
of the "air" would also be greater. Notice that the added pressure in
the tire would not effect this, as molar volume considers pressure, and
as long as you run, say, 45 lbs. of pressure in your "air" and helium
tires, the weight difference should still exist.
Also, as 1cc of Iron would be more dense than 1cc of aluminum, 1cc of
iron would have more mass and weight.
m=Vd where m=mass, V=volume, d=density
I *am* undeclared liberal arts, so any
additions/corrections/clarifications are very welcome.
Thank you,
Brian Patrick
Stewart F Hayne
to gravity, in this cas 9.81 ms-2 due to the earths gravitational field.
w=mg
there you go
--
******************************************************************
Stewart F. Hayne
Dept. of Physics sha...@uoguelph.ca
University of Guelph
Guelph ON Canada (519) 824-4120 x8542
N1G 2W1
Robert Horvatich
> In article <dave.164...@dean.dungeon.com>,
> Jollymon <da...@dean.dungeon.com> wrote:
> >
> >I think that *mass* is being confused with *weight* here. 1cc of
> >aluminum weighs less than 1cc of iron, yet the mass is the same.
> >Now if the helium causes the frame to shrink...
> >
>
> Oh my god!!! Everything I know is wrong!!!
The real truth in physics has been revealed. The planets are going
into alignment and the universe is now converging. Soon we shall know
all and the world will come to an end. Remember, it started here in r.b.o
Henry Barta
: A. Hydrogen only explodes at fusion temperatures, otherwise it burns at a
: controlled rate and is incapable of generating a shock front
: characteristic of an explosion at atmospheric pressure, as gasoline etc.
: can.
Are you sure about this? H2 has the widest flammability limits
in air of any gas I have checked flammability limits for, (Well,
not sure about acetylene...) making it one of the most dangerous
gasses to deal with in an industrial setting.
Does the low BTU content preclude the 'shock front'? And what
about combustion within an enclosed vessel, say, a CroMo steel
bicycle frame?
--
Hank Barta White Oak Software Inc.
hba...@interaccess.com Predictable Systems by Design.
Beautiful Sunny Winfield, Illinois
Henry Barta
: On 12 Oct 1995, Pete Hickey wrote:
: > In article <dave.164...@dean.dungeon.com>,
: > Jollymon <da...@dean.dungeon.com> wrote:
: > >
: > >I think that *mass* is being confused with *weight* here. 1cc of
: > >aluminum weighs less than 1cc of iron, yet the mass is the same.
: > >Now if the helium causes the frame to shrink...
: > >
: >
: > Oh my god!!! Everything I know is wrong!!!
: The real truth in physics has been revealed. The planets are going
: into alignment and the universe is now converging. Soon we shall know
: all and the world will come to an end. Remember, it started here in r.b.o
Can you tell me when as I have plans...
Pete Hickey
Henry Barta <hba...@flowbee.interaccess.com> wrote:
>Barry Logan (blo...@crash.cts.com) wrote:
>
>: A. Hydrogen only explodes at fusion temperatures, otherwise it burns at a
>: controlled rate and is incapable of generating a shock front
>: characteristic of an explosion at atmospheric pressure, as gasoline etc.
>: can.
>
> Are you sure about this? H2 has the widest flammability limits
> in air of any gas I have checked flammability limits for, (Well,
> not sure about acetylene...) making it one of the most dangerous
> gasses to deal with in an industrial setting.
>
then light them. I did, and was very disappointed in the explosion
(or lack of it). I gave up trying to get a bang out of hydrogen
pretty quickly.
> Does the low BTU content preclude the 'shock front'? And what
> about combustion within an enclosed vessel, say, a CroMo steel
> bicycle frame?
>
The hydrogen wouldn't burn at all within an enclosed vessel. It
has to be mixed with oxygen. But who would want to do that. It
would increase the weight of the bicycle.
Randall Stone
education. Check your physics texts before you all post next time.
(idiots)
jojo khalil higgenbotham
of the bike will be slightly reduced by filling the frame with hydrogen.
The mass will be increased slightly. There are two separate problems here
- a buoyancy problem and a subtle force (Newtons Law) problem.
A] Buoyancy problem: According to Archimedes principle the buoyant force
is equal to the weight of displaced fluid (in this case air). The bike in
question will displace equal amounts of air whether filled with hydrogen,
helium, argon, fart gas or nerve gas. The total force required to pick the
bike up and hold it off the ground is the combination of two forces: 1)
the buoyant force which tries to pick the bike up (by displacing air) and
2) the weight (total mass of bike times g.) which tries to pull the bike
down. The buoyant force reduces the apparent weight of the bike. If you
think about this for a minute you'll see that the apparent weight of the
bike is really only minimized when there is a (massless) vacuum inside the
frame... the buoyant force will remain the same but the weight caused by
gravity will be smaller since the frame will have lower mass (than when
filled with *any* gas). In any case, this is an excruciatingly small
difference. The mass of air in the frame is probably on the order of grams
(a paper clip is a couple of grams).
I think the true purpose of filling the frame with hydrogen is to provide
the rider with an ejection type seat... when you get in trouble, you hit
the ignitor inside the seat post, which lights the hydrogen, shooting the
seat post and whatevers on top off into the wild blue yonder! Its like the
shell under one of those old ejection seats..... You'd be like Chuck
Yeager....
B] Subtle force problem: Newtons Second Law states F=ma where F is a
force, m is the MASS of the object in question, and a is the acceleration.
The force YOU are required to apply to accelerate the bike (turn it, speed
up, etc.), depends on its MASS not its weight. By adding ANY gas to the
frame, you are *increasing* the mass!! :) Again, this will make an
excruciatingly small difference.
I suggest, and I haven't done any calculations yet, that a far greater
(and yet immeasurable) performance increase would result by simply:
cutting off the top 1/2" from one of your socks
dragging a file across a bolt or nut on the bike
cut 1" from the chinstrap on your helmet
wear a jock instead of briefs
tape your butt cheeks together and remove the bike seat
Does anyone have any suggestions for a good entry-level mountain bike for
maybe 10-30 miles per week?
email me if you do..... fsog...@mitre.org
Thanks
frank
James
>I suggest, and I haven't done any calculations yet, that a far greater
>(and yet immeasurable) performance increase would result by simply:
>
> cutting off the top 1/2" from one of your socks
> dragging a file across a bolt or nut on the bike
> cut 1" from the chinstrap on your helmet
> wear a jock instead of briefs
> tape your butt cheeks together and remove the bike seat
Don't forget to shave all your body hair to cut wind resistance and eat
nothing but black beans and rice to maximize bouyancy.
>Does anyone have any suggestions for a good entry-level mountain bike for
>maybe 10-30 miles per week?
>
>email me if you do..... fsog...@mitre.org
>
>Thanks
Just stay away from department store bikes...Go to a REAL bike dealer.
My first Mountain Bike was a Trek. I was pretty happy with it. I looked
at a lot of bikes and went to a lot of dealers and for the price, features
and workmanship I think it was the best deal under $700. There are a lot of
good bikes Under $400.(Trek, Specialized, etc...) I've seen a LOT of people
riding Diamondback bikes. Those would be three worth checking into.
Happy Trails
James
terry butler
I've just purchased my first bike (if you don't count 3 years on an el
cheapo from the highsteet)... I bought a GT Timberline, c/w with bar ends
I got it for 310 UKP (was 445 UKP, see we pay dearly here in the UK!).
Not the best I know but it emptied my pockets (for now)...
Happy ped'lin'...Terry
Marin Gazzari
>
><sigh>.... as a Physics teacher I can tell you that the *apparent weight*
>of the bike will be slightly reduced by filling the frame with hydrogen.
>The mass will be increased slightly. There are two separate problems here
>- a buoyancy problem and a subtle force (Newtons Law) problem.
Being a physics teacher, you should know that hydrogen has a lower mass
than air at the same pressure. If you fill a frame with hydrogen, the
bike's mass WILL be reduced (by a very small amount).
BTW, road racers sometimes DO pump up their tires with helium, since
at higher pressures, the difference is even bigger, and it's more important
in the wheels, since it's rotating mass.
John Stevenson
i_h...@night.com (jojo khalil higgenbotham) wrote:
><sigh>.... as a Physics teacher I can tell you that the *apparent weight*
>of the bike will be slightly reduced by filling the frame with hydrogen.
>The mass will be increased slightly. There are two separate problems here
>- a buoyancy problem and a subtle force (Newtons Law) problem.
<sigh> If you really believe this, and this whole post isn't an enormous
wind up, then you should turn in your teachery qualification right now.
Your grasp of the laws of physics probably qualifies you as a politicianÉ
If you replace the air in a bike frame with a less dense gas, the total
mass of the bike will be reduced and it will weigh less. Period. Simple.
End of story. Your discussion of Archimedes Principal misses the key point;
a frame filled with air doesn't displace the air it is filled with, so
there is no 'bouyancy force' from that displacement. As soon as you replace
the air with a lighter gas, then there is a bouyancy force equal to the
difference in weights of the two gasses.
As for your discussion of Newton's second law, you're obviously not aware
that gravitational mass (which is what produces weight in a gravitational
field) correlates exactly to inertial mass. If it didn't the universe would
be a very different and possibly more interesting place. Replacing the air
in a frame with a lighter gas reduces its mass. Period.
I don't believe I've been sucked into this thread. It must be time to kill
it off.
Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis
Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis
Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis
Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis Nazis
Nazis Nazis Nazis Nazis.
That ought to do it.
John
John Stevenson
john...@world.net
jojo khalil higgenbotham
(John Stevenson) wrote:
I said:
> The mass will be increased slightly.
OOOOOOOOHHHHHHHHHHHH... i should be killed...... if you replace AIR with
H/He the mass decreases.... thanks for catching my most egregious
error......
> Your grasp of the laws of physics probably qualifies you as a politicianÉ
nyuk nyuk nyuk....
>
> If you replace the air in a bike frame with a less dense gas, the total
> mass of the bike will be reduced and it will weigh less. Period. Simple.
> End of story. Your discussion of Archimedes Principal misses the key point;
HOHOHOHO... boy is my face red...... if you replace the air in the frame
with H/He... the mass decreases (my red face)... the lowest possible mass
is attained with a vacuum.... as a practical matter not doable... but
adding any gas to a vacuum *increases* the mass.... this was the intent of
my original statement (admittedly vague about the vacuum bit... but seemed
to create a good angry response!)
> a frame filled with air doesn't displace the air it is filled with, so
> there is no 'bouyancy force' from that displacement. As soon as you replace
> the air with a lighter gas, then there is a bouyancy force equal to the
> difference in weights of the two gasses.
I'm not sure i said there was a nonzero buoyant force when the frame was
filled with air... if you say i did... then i musta.... clearly there is a
bouyant force when the frame is filled with anything that has different
density than air.....
>
> As for your discussion of Newton's second law, you're obviously not aware
> that gravitational mass (which is what produces weight in a gravitational
> field) correlates exactly to inertial mass. If it didn't the universe would
> be a very different and possibly more interesting place. Replacing the air
> in a frame with a lighter gas reduces its mass. Period.
>
gravitational mass... inertial mass.... ummmmmm... well you ARE correct...
grav. mass and inertial mass correlate exactly..... I'm not sure how that
clarifies or corrects anything.... I guess the point is this: reducing the
mass of the bike is a good thing. Changing from air to H/He filled would
be a good thing since the mass would decrease.
Someone else pointed out that 22.4 L of H at STP (or He?) has a mass of 5g
as opposed to air (about 25g). If your frame holds even 1/10 of this
volume (that'd be about 2.24L at STP) that'd be a reduction in mass of 2
grams.... (He over Air)....
I don't know..... I'm only qualified to be a politician.... but 2 grams
does not seem like a lot of mass when compared with that of a bike and
rider. You could easily lose more than 2 grams by getting a haircut
(depending on how much hair you have).
Someone else pointed out that:
> BTW, road racers sometimes DO pump up their tires with helium, since
> at higher pressures, the difference is even bigger, and it's more important
> in the wheels, since it's rotating mass.
Again.... I'm only qualified to be a politician, so this had never ocurred
to me.... but this is a *good reason* for using He in tires. Perhaps John
can now tell us how this relates to intermediate vector bosons :)
adios
Chris Blain
streamlined exhaust at the other end of the frame, then air will flow
freely through the frame and you wouldn't need to worry about
accelerating its mass. This would translate to a lower inertial mass, no?
-Chris
B /\ U Chris Blain (chr...@bdel.com)
S Black Diamond Equipment Ltd.
D \/ A 2084 East 3900 South, SLC, UT 84124 phone: 801-278-5552
DISCLAIMER: Unless otherwise indicated, this correspondence is personal
opinion and NOT an official statement of Black Diamond Equipment Ltd.
sean
> [a whole load of generally useless information cut out because it annoyed me]
>
> Just a question -- why the hell do you feel it is nessasary to continue
> this thread that as far as I know has been going on (in one form or
> another) since the beginings of this ng?
Hmmmm... Too bad this was not cross-posted! :)
Sean
Henry Barta
: If you replace the air in a bike frame with a less dense gas, the total
: mass of the bike will be reduced and it will weigh less. Period. Simple.
: End of story. Your discussion of Archimedes Principal misses the key point;
: a frame filled with air doesn't displace the air it is filled with, so
: there is no 'bouyancy force' from that displacement. As soon as you replace
: the air with a lighter gas, then there is a bouyancy force equal to the
: difference in weights of the two gasses.
: As for your discussion of Newton's second law, you're obviously not aware
: that gravitational mass (which is what produces weight in a gravitational
: field) correlates exactly to inertial mass. If it didn't the universe would
: be a very different and possibly more interesting place. Replacing the air
: in a frame with a lighter gas reduces its mass. Period.
Gravitational mass? Inertial mass? Negligible bouyancy....
OF COURSE! We've been going about this the wrong way! Reducing
the mass of the bike is difficult and expensive. But it's really
WEIGHT that is the problem isn't it? So why knock off a few
grams here and there when we can drop many pounds from both
rider and bike by riding on the moon! And as an added benefit,
there are NO places on the moon where bikes are banned, and
very few hikers and no equestrians to contend with. There's
not even any wildlife, so I'm sure that Mike V. will be pleased!
Why is it that these answers seem so obvious once we've stumbled
onto them?
sean
> Gravitational mass? Inertial mass? Negligible bouyancy....
>
> OF COURSE! We've been going about this the wrong way! Reducing
> the mass of the bike is difficult and expensive. But it's really
> WEIGHT that is the problem isn't it? So why knock off a few
> grams here and there when we can drop many pounds from both
> rider and bike by riding on the moon! And as an added benefit,
> there are NO places on the moon where bikes are banned, and
> very few hikers and no equestrians to contend with. There's
> not even any wildlife, so I'm sure that Mike V. will be pleased!
Wow! Now this really opens a whole new area, doesn't it!! The moon also
had virtually no atmosphere. This would be a tremendous boon for a biker
as they would have the effect of friction nearly non-existant. How about
instead of having the inside of the bike frame a vacuum, just ride in a
vacuum? Just think....No friction at all!! Well, at least no air/wind
friction. Must remember that gravity would still exist in my vision thus
friction with the ground would still exist. Now if I could just create
that anti-gravity devise.....
Until sometime in the future...
Sean
Aaron Baldwin
In Article<478li7$9...@nntp.interaccess.com>, <hba...@flowbee.interaccess.com> write:
> Path: news.zeitgeist.net!bdt.com!rmstar.efi.com!nntp-hub.barrnet.net!inet-nntp-gw-1.us.oracle.com!news-out.internetmci.com!internetMCI!newsfeed.internetmci.com!news.kei.com!hookup!tank.news.pipex.net!pipex!news.sprintlink.net!news.bluesky.net!solaris.cc.vt.edu!swiss.ans.net!newsjunkie.ans.net!in
teraccess!flowbee!hbarta
> From: hba...@flowbee.interaccess.com (Henry Barta)
> Newsgroups: rec.bicycles.off-road,alt.mountain-bike
> Subject: Re: Helium/Hydrogen filled frame and tires.
> Date: 1 Nov 1995 20:33:11 GMT
> Organization: InterAccess, Chicago's best Internet Service Provider
> Lines: 35
> Message-ID: <478li7$9...@nntp.interaccess.com>
> References: <455udt$g...@mercury.dur.ac.uk> <45besm$a...@newsbf02.news.aol.com> <45dtna$j...@hermod.uio.no> <dave.164...@dean.dungeon.com> <i_hunt-2610...@m23374-mac.mitre.org> <ACB7D8E2...@sydney44.world.net>
> NNTP-Posting-Host: flowbee.interaccess.com
> X-Newsreader: TIN [version 1.2 PL2]
> Gravitational mass? Inertial mass? Negligible bouyancy....
>
> OF COURSE! We've been going about this the wrong way! Reducing
> the mass of the bike is difficult and expensive. But it's really
> WEIGHT that is the problem isn't it? So why knock off a few
> grams here and there when we can drop many pounds from both
> rider and bike by riding on the moon! And as an added benefit,
> there are NO places on the moon where bikes are banned, and
> very few hikers and no equestrians to contend with. There's
> not even any wildlife, so I'm sure that Mike V. will be pleased!
>
> onto them?
I agree with Henry, who the hell care if you nock off a few grams! If you
look at the periodic table, please tell me the difference between the
gasses... Secondly if you expect by pumping you tires up with helium is going
to help much think again. The wieght of oxygen in a pumped up tire is not
going to be big enough to even care about.
Lord Vader
>Just a question -- why the hell do you feel it is nessasary to continue
>this thread that as far as I know has been going on (in one form or
>another) since the beginings of this ng?
>It's just plain not practical -- tires lose pressure with He in less time
>than a short ride (would you carry a He tank with you then? Kind of
>negates the purpose of having it there in the first place doesn't it?)
(snip)
I once heard of some track racers fill their tires with Nitrogen to 200+ psi.
Tire pressure would hold up for the duration of the ride and thats about it.
Anyway only road weenies would do that, heck we are real bike riders here, we
under infalte our tires!! :)
Jay Curry
>
>On 10 Oct 1995, Tom Andre Sj|lie wrote:
>
>>
>> >does NOT reduce the bike's mass. Thus even if the silly thing floated, it
>> >would still be just as hard to move it forward, to turn it, to stop it....
>>
>> That is WRONG!!!
>> It WILL reduce the mass of the frame, although very little.
>
>addition of more helium molecules (He2). You can not decrease the mass
>of one material by adding the mass of another material to it.
>
>>
>
>
>> Tom
>
>
>email: |"You can't take life too seriously,
>rho...@tbd.ford.com | you don't get out alive." Bugs Bunny
>
>
Chris Foote
I'm no physics expert, bu the best way to drop the mass is by not
filling the tube with anything. A vacuim would be the answer, but it
wouldn't do a helluva lot.
John Bratton
>From: cfo...@ccinet.ab.ca (Chris Foote)
>Subject: Re: Helium/Hydrogen filled frame and tires.
Folks, why does a helium-filled balloon float? Because the ballon (and the
enclosed helium) is occupying less space than the air it displaces. Why does a
steel ship float? A vacuum WOULD be better, but the ballon needs the pressure
to occupy space and displace air. Would a helium-filled frame or tire weigh
less (even if you could keep the stuff inside)? I guess so- just figure the
weight of the air inside normally, and substract the weight of helium and
that's the weight you would save.