Carbon fiber and sub-freezing temperatures? is there a problem?
 

due to circumstances beyond my control, i am forced to store some of my carbon wheels (campagnolo, zipp, lightbicycle) outside, in wheel bags, in boxes (hopefully by tomorrow), covered in either plastic sheeting, or in soft-shell bicycle bags.
they are under an awning, so hopefully wont get too much snow.
the temps are going down below freezing, and then thawing during the day.
will they be ok?

Yes.

Carbon fiber airplanes with 7-8psi fuselage pressure differential, with carbon fiber components and control surfaces exposed to the force of 600mph winds and fly where the temperature is easily -50f and lower and cycle to where it is +100f several times a day for 25 years or more and don't have any issues.

What conclusions can you infer from the above information about the carbon fiber construction of your wheels?

https://iopscience.iop.org/article/1...6/1/012047/pdf

A while ago I was looking into what happens to bikes when you dunk them in liquid nitrogen (There is essentially unlimited I can access at work), and came to the conclusion that it wouldn't hurt a carbon frame, might even help it. Didn't get around to testing it

wow, thanks for the quick replies

Nothing. Unless you can show the resin, mat, and layups used in aircraft are the same as bicycles.

But, they don't use carbon fiber wheels on airplanes. What does that tell you?:)

Unless the resins are the same, there are no conclusions you can draw. The resins are (as far as I know) epoxies. There are epoxies formulated to do just about anything but each specialty comes with properties that are drawbacks for other uses.

What we can infer is that "carbon fiber" as it is colloquially known, is stable and retains it's properties in service through extreme and wildly varying conditions.

The darn things will be fine.

Thousands of carbon fiber fat tire bikes. with carbon fiber wheels are used all winter in snowy climates

They might get frostbite or hypothermia. But I doubt they will complain.

Just don’t let the carbon fiber get wet or feed it after midnight.

NOW you tell me!

Please do not compare aerospace grade carbon fiber products to carbon fiber bicycle frames.

So pouring water on a basketball and watching it roll off doesn't prove the earth is not round?... :)

I just did! Carbon fiber is a versatile and lightweight material that finds applications in various industries, including aerospace and bicycle manufacturing. While there are some similarities in the use of carbon fiber in these two fields, there are also notable differences. Here are some key distinctions between aerospace and bicycle applications of carbon fiber:

1. Performance Requirements:
   
   • Aerospace: Aerospace applications often require extremely high-performance materials due to the demanding conditions of space travel and aviation. Carbon fiber used in aerospace must meet stringent standards for strength, stiffness, and durability to withstand the forces encountered during takeoff, flight, and re-entry.
   • Bicycles: While bicycles also benefit from lightweight and strong materials, the performance requirements are generally less extreme compared to aerospace. Bicycles need to balance factors like weight, stiffness, and aerodynamics, but the safety margins and performance characteristics are not as critical as in aerospace.
2. Material Grades and Specifications:
   
   • Aerospace: Aerospace-grade carbon fiber typically adheres to strict industry standards and specifications. The materials used in aerospace applications undergo rigorous testing and certification processes to ensure they meet safety and performance requirements.
   • Bicycles: Carbon fiber used in bicycles can vary widely in terms of quality and specifications. High-end bicycles may use advanced carbon fiber composites, but there is a broader range of grades and specifications in the bicycle industry compared to aerospace.
3. Manufacturing Techniques:
   
   • Aerospace: Aerospace components are often produced using advanced manufacturing techniques such as autoclave curing, which involves applying heat and pressure to the composite materials. The goal is to achieve a high level of precision and uniformity in the final product.
   • Bicycles: Bicycle manufacturers may use a variety of manufacturing techniques, including less expensive methods like bladder molding or resin infusion. While high-end bicycles may also use autoclave curing, the production scale and cost considerations are different from aerospace.
4. Cost Considerations:
   
   • Aerospace: The cost of materials and manufacturing processes in the aerospace industry is typically much higher than in the bicycle industry. The stringent requirements for safety and performance contribute to the elevated costs.
   • Bicycles: Cost is a significant factor in the bicycle industry, where manufacturers often balance performance with affordability. This can lead to a wider range of carbon fiber grades and manufacturing processes being employed.
5. Scale of Production:
   
   • Aerospace: Aerospace applications are characterized by low production volumes and high levels of customization. Each component is carefully engineered and produced to meet the specific requirements of the spacecraft or aircraft.
   • Bicycles: Bicycle manufacturing involves higher production volumes, and there is a broader range of designs and specifications to cater to different market segments. Mass production techniques are more common in the bicycle industry.

In summary, while both aerospace and bicycle applications of carbon fiber share the goal of achieving lightweight and strong structures, the specific requirements, manufacturing processes, and cost considerations differ significantly between these two industries.

not to be weird, but did you use ai to help write this? I’m paranoid and see it everywhere now.

"help" :lol:

In response to accusations about using AI, I clarify that AI serves as a tool to enhance productivity and efficiency in various tasks. It's not a replacement for human capabilities but a complementary technology designed to streamline processes and provide valuable insights. I highlight the practical benefits I've observed, such as improved efficiency and effectiveness in different projects. I take a moment to educate on the nature of AI, emphasizing that it simulates human intelligence in machines. Additionally, I stress the importance of responsible AI deployment and ethical considerations. I welcome further discussion, offering examples of how AI has positively impacted my life and social interactions. Overall, my response aims to be transparent and informative, addressing any misconceptions about the role and implications of AI in my activities.

Can you not think of a better way to respond to the post regarding Aerospace vs Bicycle carbon fibre? Very efficient and informative.;)

they don't use carbon fiber wheels on aircraft because of the heat build up in the brakes. A worst case refused takeoff at max gross and emergency stop with no reverse thrust is an FAA required test, aircraft has to sit 5 min and then taxi some distance. The tires have fuseable plugs that blow out, and the brakes glow cherry red.

even on routine landings with moderate braking (autobrake 3 on a 737) you see brake temps of 700C. Which would soften the epoxy that bonds the carbon fiber together.

this is an entirely different use case than wheels on a bike. Not remotely comparable

to answer the @OP's question - storing carbon fiber parts outside should not be a big problem, won't hurt the material, you may see slightly increased brittleness in response to shock loads at low temps.

/markp

You didn't notice that smiley emoji, did you?

Do eeet! Post the vid.

I hate to admit it, but it sure does read like AI. Of course, Larry is probably AI as well, so it could just be a case of AI rivalry.

For the purposes of this discussion, you most certainly can compare and draw conclusions from the aerospace industry use. The epoxies may differ somewhat in formulation and you probably wouldn’t use aerospace grade epoxies on bicycles or vice versa, but in terms of their respective properties, they are close enough. Cold isn’t going to have much effect on either. For their applications, both will stand up to their task equally.

The only caveat is to avoid getting water trapped in the rim. Not just dampness but pools of water in the rim. The expansion of water while freezing will likely crack the rim. But that would hold for any bicycle rim. It’s also not something that is common in bicycle rims at all so it’s not really worth worrying about.

Larry is AU. I'll let you figure out what that stands for.