LarrySellerz

Its gobbledygook. The kids are work (physics phds, supposed to be the future leaders and great thinkers) are using it and producing nonsense, its killing the soul of the world

LarrySellerz

unfortunately, earlier this week we almost exploded our cryo-coffin because cryogen (either liquid nitrogen leaking in or liquid argon and liquid oxygen getting pumped in from a leak to the outside, which was later frozen over with water ice and made a bomb.) We didn’t put a pressure relief on the insulating space and sealed it off completely like dummies.

But yeah once we fix it up and add pressure relief (putting a scroll pump on it managed to implode it and it looks fine except for the pictured unistut on the inside) I can maybe take one of my spinergy rev-x wheels sitting in my parents garage and do a dunk test. Can’t find a 650 c bike that fits me to put it on except for the tri things and I have a bad back, would be hard to ride.

the previous iterations of these dewars had fiberglass walls, sheets of fiberglass layered with epoxy I think, that’s kind of like carbon fiber. They wouldn’t have used that if it failed when cold

wolfchild

AI isn't a substitute for actual real world experience. That's the problem with social media and forums. People post all types of impressive stuff and make it sound like they know something, when in reality they never experienced what they talking about. They just copy something form internet and pretend like it's their idea or experience. Too many fake people out there today.

Atlas Shrugged

I appreciate your perspective on the use of AI in the context of discussing carbon fiber applications in aerospace and bicycles. It seems there's a recognition that the comment aimed to discredit carbon fiber in bicycle frames and components was based on a somewhat unreasonable premise. While AI can certainly contribute valuable insights and information to discussions, it's important to consider the nuances and practical applications of materials like carbon fiber, especially in fields where it has proven successful, such as high-performance bicycles. If you have further thoughts or questions on this topic, feel free to share!

t2p

the largest most powerful jet engine has carbon fiber fan blades

downtube42

I've never experienced the spherical nature of the earth, but I don't think it's fake of me to speak of it as a truth. Experience may be a good teacher, but it's not the only teacher.

Can AI itself have experiences? What does that even mean, having experiences? I guess when AI can do something, then observe the consequences, that's an experience.

jon c. 

AI programs are a source of information. As with any other source, if used in print it should be appropriately cited. To copy written work created through AI and present it as if were your own writing is no different than copying work created by a human and presenting it as your own. It's dishonest.

Koyote

Just wait until Skynet becomes sentient.

Koyote

And yet, many bf posters just regurgitate other people's opinions. What's the difference?

Chuck M 

While everyone was arguing aerospace vs. bicycle and questioning AI as the source of a post, the OP's wheels were at a greater risk of theft than freezing to death.

Troul 

mannn this thread snowballed down a cold mountain side.

unless the parts are getting impacted in ways that they would not normally be hit with force (a side hit to the frame tubes) I wouldnt see an issue.... The bearings (if any) might not like it out in the cold if they are not moisture free & poorly lubed up.

indyfabz

Do you have any expressions of thoughts that are wholly your own? If not, I may be compelled to report your reliance on AI, Data.

MinnMan

And yet, somehow the sun comes up in the east. Every day.

CrimsonEclipse

It's as bad (laughable) as comparing aluminum bikes to aluminum airframes.

2 completely different industries, different stresses, certification standards, manufacturer standards, liabilities, inspections, and regulations.

so... nothing.

Atlas Shrugged

I have expressed my opinions numerous times when it comes to the ridiculous trolling posts of how Carbon Fiber is a poor choice for bicycle frames and components even though it dominates the industry. In this case I felt the only reasonable response should be automated brainless AI generated because the recipients stance is based an outdated imprinted opinion generated decades ago and unlikely to change.

Sorry everyone, I thought it would be a smart ass way of answering an obvious baiting post. With that I am out and apologize for participating or possibly instigating this train wreck.

CrimsonEclipse

In short, they will be fine.

Most cheap CF is fine from -20c to 50c with minimal change in strength properties.
For instance: deflection under similar stress in the temperature range is within 5%

Note: all CF in the cycling industry is cheap compared to aerospace and higher technologies.

Anecdotal observation:
There is no pattern of massive failure of CF bicycle components in cold weather and snow bikes are not intentionally manufactured with special cold weather CF.

Don't worry about the cold my friend.

(I'd be more concerned about sticky fingers than the cold)

MinnMan

Interesting. Considering the care, cost (and cost/g) and fuss that people make over high-end carbon framesets, and on the other hand, considering that aerospace carbon is produced by the ton, one would think that there would be a crossover point at the high end.

indyfabz

Don’t always trust your feelings.

No AI was used in the generation of this post.

SpeedyBlueBiker

They should be fine. Your biggest risk is some no goodnik coming over and stealing them if they are left outside.

CrimsonEclipse

Maybe the top 1%.
Nah, make that top .1%

CF Bike frame fails, it occasionally makes BF.
Rarely results in federal investigation or lawsuit.

Just one CF airplane crashes........

base2 

I am curious as to your professional credentials regarding carbon fiber repair. Taken any classes? I have. For at one time there was an intercompany transfer I was vying for. I got to do all sorts of cutouts and patterns with various grades of pre-preg, and all the stuff of internal structure like honeycomb, mesh screen, etc...All a fair bit more complex from an engineering perspective than a bicycle. None of the raw material is terribly complex or all that much different. There is a fair bit of overlap between the two. I've even repaired my own carbon wheels.

Aircraft make a fair bit of use of 7000 series aluminum. Quite a few bicycles use 7000 series aluminum. Raleigh R300 comes to mind. As does any bike made from "Scandium." Actual premium components are made from 7000 series aluminum too. This is how companies like Extralite can make stems & hubs that weigh considerably less than just expensive "premium" Chris King or White Industries at half the cost of DT Swiss' best offerings.

Of course, most cheap bicycle uses of aluminum are 6000 series because it is cheaper, and not as susceptible to crack propogation. It's absence of strength in comparison to better grades makes it way easier to justify tube thickness which makes for a more durable bicycle. You can find 6000 series aluminum in some secondary structure airplane parts where strength requirements are low and excess cost of higher grade isn't justified. Shelving brackets in the galley or lavatory, for example.

The big cost in aerospace is engineering of the component, the certification of said component, and tracability from cradle to grave. Not the cost of the material itself.

Don't tell me there is no overlap. It's all overlap. All knowledge is derivative. The engineering constraints of a rigid long lasting structure at the absolute minimum weight possible, performing at the highest efficiency achievable at the minimum necessary strength to do the job within acceptable lifecycle safety margins is the same for both applications.

It's almost like people forget how to think. To take what is known about broad concepts to reason themselves through a problem to make a reasonable guess on a specific scenario.

Because airplanes are not bicycles nothing can be anything...That's just ignorant.

CrimsonEclipse

Let's just say that I'm in the aeronautical industry and I've taken a few classes and certified at the federal level, and my skills and experience are trusted by a successful company. Said skills include: Structures, materials, manufacturing, integration, certification, testing (destructive and NDT), repair, and post failure investigation.

So your rambling post shoes me that you know the very basics of aluminum alloys and CF, but it's obvious that you are completely unqualified to make the comparison.

To the point:
The cycling world commonly uses the term "Aerospace Quality X" or aviation grade or such non sense

You will never see Boeing say: "We have cycling quality CF in our airplanes"

Seriously, we'll laugh you out the door.

And I'm not wasting my time correcting you on every single materials error you posted.

terrymorse 

TL;DR The temperature swings that carbon fiber composite would be subjected to on a cold night won't harm the structure.

In contrast, the temperature extremes that space hardware experience are more severe than even high altitude aircraft see, and that's when you been to worry about thermal stresses (worrying about that stuff used to be my job).

High temperature swings can produce micro cracks in the resin of carbon composite, usually starting at a void. A crack propagates through the layer until it reaches the next layer with a different fiber orientation. These cracks weaken the laminate structure, but only slightly. They also reduce the stiffness, sometimes significantly.

But fear not, concerned cyclist, as the space temperature range is -196C to 180C.

Iride01 

Still you can infer a lot. When you get down to the level of the things you mention, then you are being more specific, the inferring might change at that time.

There is no requirement for the inferring to be correct. It just has to seem reasonable for the information known at that time

base2 

CrimsonEclipse So, because airplanes are not bicycles nothing can be anything.

Good one.


The Op's question, plainly stated: "Will cold weather hurt my wheels?" Well Crimson, will it? Care to present a known "bicycle carbon" reason why it will? Or will general carbon know-how from the largest use of carbon fiber in industry suffice for the purposes of the question?

Are you going to cop-out behind engineering speak along the lines of: "Due to the absence of specific laboratory performance testing between the ranges of 25 to 32 degrees farenheit, no conclusion can be drawn concerning the performance impact of cold weather on the OP's wheels." Which, while that may be singularly true, and validate your own ego and safeguard the credibility of the license of your particular specialty, is not actually helpful.

...All this from an approach to prompt the OP to reason himself through his own question and arrive at his own conclusion. Sheesh.