Sub 500g frame

tunney

http://www.cyclingnews.com/news/photos/special-tech-news-impossible-think-again/113262

(yes I know the date, its a good one though)

niceonetom

Yowza! How little BF would I have to have to justify that?

(it's better than most I suppose)

Doc_Savage

sorry i've studied thick and thin cylinders and internally pressurized compound cylinders... this appears to me marketing crap. unless it's got a vaccum in it i can't see it benefitting the strength weight ratio.. putting a tube under constant stress (not strain) will shorten it's working life and make it prone to sudden failure and buckling.. so says Euler anyway!

If they have gotten it to work then fair play!

But i still think this is just a really really light frame with a gimmick attached!

seamus

Better yet, filling it with pressurised hydrogen will reduce the weight further!

Though, don't crash.

Lumen

I've wondered for a while why frame mfrs don't fill tubes with foam to increase stiffness. From what I recall it's an approach commonly used (with sheet materials anyway) in motorsport engineering.

niceonetom

blorg

Doc_Savage wrote: »

sorry i've studied thick and thin cylinders and internally pressurized compound cylinders... this appears to me marketing crap. unless it's got a vaccum in it i can't see it benefitting the strength weight ratio.. putting a tube under constant stress (not strain) will shorten it's working life and make it prone to sudden failure and buckling.. so says Euler anyway!

If they have gotten it to work then fair play!

But i still think this is just a really really light frame with a gimmick attached!

Why do they pressurise aircraft then? And they must be really light, after all they float.

niceonetom

Lumen wrote: »

I've wondered for a while why frame mfrs don't fill tubes with foam to increase stiffness. From what I recall it's an approach commonly used (with sheet materials anyway) in motorsport engineering.

Guess: Do the UCI still insist that bikes are made from tubes, i.e. hollow in the middle? If not, then I can't see why internal foam or re-enforcing isn't used. It would, at the least, make for good marketing copy.

Raam

I'd buy it.

Doc_Savage

seamus wrote: »

Better yet, filling it with pressurised hydrogen will reduce the weight further!

unless it's got a vaccum in it i can't see it benefitting the strength weight ratio..

surely nothing could be lighter than nothing?

From what I recall it's an approach commonly used (with sheet materials anyway) in motorsport engineering.

yes aluminium foam... mostly for impact absorption and attenuation.. it's mad stuff, a mate's doing his thesis on the stuff!

jwshooter

cool . another thing to blame . i forgot to pump my bike.

mloc123

can I get it with a '450G' logo on the frame?

IM0

the story on Boonen is a better one :D..or maybe the one about Divinci's flying bike? (nah too obvious that one)

leftism

I always wondered why bike manufacturers didn't experiment with carbon/foam sandwiches and vacuum packing when building composite bikes. It has worked so effectively in boat building (americas cup yachts etc.) and motorsport.

Reduced weight and higher rigidity cannot be a bad thing....

WhisperingDeath

Smells like April fool to me. You guys should know better..

blorg

WhisperingDeath wrote: »

Smells like April fool to me. You guys should know better..

I don't think so, they have a picture of the valve to pump it up

Lumen

blorg wrote: »

I don't think so, they have a picture of the valve to pump it up

I Googled Schrader valves yesterday (wondered about 300psi) and they do all sorts of high pressure valves, up to 15,000psi.

So it's plausible.

WhisperingDeath

Impressive if somewhat concerning credulity.

Check out the website: http://www.carboncopycomponents.com/

Lumen

WhisperingDeath wrote: »

Impressive if somewhat concerning credulity.

Check out the website: http://www.carboncopycomponents.com/

Ha ha. I is pwned.

blorg

Lumen wrote: »

I Googled Schrader valves yesterday (wondered about 300psi) and they do all sorts of high pressure valves, up to 15,000psi.

So it's plausible.

I knew Schrader did high pressure; most suspension forks use a Schrader valve and run at high pressures. So as you say, plausible.

JacksonHeightsOwn

you shower of ejits

i copped it once i clicked onto their website

im still slightly annoyed it took me that long...... but to think you could actually pump up your frame

hang your heads in shame!

and to think ,you lads probably have degrees and

blorg

chrisbonnie wrote: »

im still slightly annoyed it took me that long...... but to think you could actually pump up your frame

Why do they pump aircraft then? I realise they have more room for pumping as the whole fuselage is one big tube but it is hardly unreasonable to think that you could get a bike frame down to 450g at 300 PSI. 300 PSI is pretty high pressure.

JacksonHeightsOwn

blorg wrote: »

Why do they pump aircraft then? I realise they have more room for pumping as the whole fuselage is one big tube but it is hardly unreasonable to think that you could get a bike frame down to 450g at 300 PSI. 300 PSI is pretty high pressure.

its not as high as 400psi though is it :cool:

blorg

chrisbonnie wrote: »

its not as high as 400psi though is it :cool:

You need to use a shock pump to pressurise the frame. 400 PSI would be impractical as shock pumps don't go that high. Obviously airlines have mechanised pressurisation systems and can go higher.

Nietzschean

blorg wrote: »

Why do they pump aircraft then? I realise they have more room for pumping as the whole fuselage is one big tube but it is hardly unreasonable to think that you could get a bike frame down to 450g at 300 PSI. 300 PSI is pretty high pressure.

aircraft are pressurized to make them more comfortable for the ole humans in them? unless your referring to something else in them being pressurized?

blorg

Nietzschean wrote: »

aircraft are pressurized to make them more comfortable for the ole humans in them? unless your referring to something else in them being pressurized?

This is in the context of the transfer of technologies from the aerospace industry to bicycles. Titanium and subsequently carbon fibre saw wide use in aerospace before being transferred to bikes. Pressurisation is of course essential for passenger comfort (and indeed consciousness) but the flip side is that it, along with these space age materials, makes the plane lighter and better able to float. It is this latter application that has been transferred to this new bike frame.

I don't know how applicable it will be to a bike in practical terms as the volume inside a aircraft fuselage is in a far greater ratio to the material making up the skin- but the theory is sound, and these guys are claiming a 450g frame weight, which is (AFAIK) a fair reduction on current extreme lightweight frames such as Gunter's 667g one. Even presuming this claimed weight is optimistic a sub-500g frame is a major achievement. I could see Tour riders going back to Brooks with a frame this light, you would need to look out for stuff to build it up 6.8kg.

de_Selby

Lumen wrote: »

I Googled Schrader valves yesterday (wondered about 300psi) and they do all sorts of high pressure valves, up to 15,000psi.

So it's plausible.

blorg wrote: »

Why do they pump aircraft then? I realise they have more room for pumping as the whole fuselage is one big tube but it is hardly unreasonable to think that you could get a bike frame down to 450g at 300 PSI. 300 PSI is pretty high pressure.

It's pretty hard to tell whether you're joking or not..

How can pumping a gas (at a high pressure no less, so a lot of gas) reduce the frame's weight? Is it some magic gas with negative weight? Doc Savage got it right on the previous page - nothing can be lighter than nothing.

Re: pressurising aircraft - they pressurise the cabin so we can breath properly, the density at altitude is too low for our lungs to work efficiently, the same reason why climbers need oxygen tanks when climbing Everest (and our bodies can't cope with the sudden changes in atmospheric density from climbing that fast even at lower altitudes). It has nothing to do with buoyancy.

de_Selby

blorg wrote: »

Pressurisation is of course essential for passenger comfort (and indeed consciousness) but the flip side is that it, along with these space age materials, makes the plane lighter and better able to float.

but it doesn't. Pressurisation makes the plane heavier, adding extra air=heavier.

Lumen

de_Selby wrote: »

It's pretty hard to tell whether you're joking or not..

Yeah, he does that. Just wait until the TdF starts..

blorg

de_Selby wrote: »

Re: pressurising aircraft - they pressurise the cabin so we can breath properly, the density at altitude is too low for our lungs to work efficiently, the same reason why climbers need oxygen tanks when climbing Everest (and our bodies can't cope with the sudden changes in atmospheric density from climbing that fast even at lower altitudes). It has nothing to do with buoyancy.

The cabin is pressurised to equivalent atmospheric pressure at 2,000-2,500m. The air at that altitude is quite light. How does the air at 2,000m get there? It floats above the heavier air closer to the ground. Balloons have made use of this principle for thousands of years. This is also why it is so insufferably hot in aircraft cabins incidentally.

Lumen

de_Selby wrote: »

they pressurise the cabin so we can breath properly, the density at altitude is too low for our lungs to work efficiently, the same reason why climbers need oxygen tanks when climbing Everest (and our bodies can't cope with the sudden changes in atmospheric density from climbing that fast even at lower altitudes

Climbers use oxygen because looking down makes them feel dizzy.

de_Selby

blorg wrote: »

The cabin is pressurised to equivalent atmospheric pressure at 2,000-2,500m. The air at that altitude is quite light. How does the air at 2,000m get there? It floats above the heavier air closer to the ground. Balloons have made use of this principle for thousands of years. This is also why it is so insufferably hot in aircraft cabins incidentally.

But the air at 10,000m further up, where aircraft fly, is even less dense/lighter again, hence the use of the word pressurised and not depressurised.

I'm not sure what you mean about the heat.

blorg

de_Selby wrote: »

But the air at 10,000m further up, where aircraft fly, is even less dense/lighter again, hence the use of the word pressurised and not depressurised.

I'm not sure what you mean about the heat.

Hot air is lighter than cold air and rises. To get to 10,000m they have to get off the ground first.

de_Selby

blorg wrote: »

Hot air is lighter than cold air and rises. To get to 10,000m they have to get off the ground first.

As air is heated it gets less dense, so a given volume will be lighter, but that doesn't mean that air is hotter the less dense it is.
Also, the cabin is only pressurised after takeoff.

blorg

de_Selby wrote: »

Also, the cabin is only pressurised after takeoff.

Yes, but this bike you pump up at home before you go on your ride. You probably have to deflate it before taking it on an aeroplane.

de_Selby

.. which would only make it heavier.

Well, I've had enough of your trolling! I've got to learn to stop replying to people who are ripping the piss.

lyders

The weight loss is due to using less carbon, because you pre-tension the carbon by pumping it with air. The weight loss is not due to simply pumping the frame with air. Newton would hang his head in shame if he read this thread!

The article is just an April Fools joke anyway!

blorg

de_Selby wrote: »

Well, I've had enough of your trolling! I've got to learn to stop replying to people who are ripping the piss.

I resemble that remark!

It is Friday.