Bikeframe analysis
Analyzing the impact of riding over cobbles on steel and carbon frames
Course
Computer Aided Engineering
Tools
Siemens NX
Project Type
Individual academic project
Date
october 2024 - january 2025
CONTEXT
Cycling technology has seen significant evolution, with a shift in material choices for road bikes.
Modern Road Bikes:
Primarily constructed from carbon fiber.
Offers lighter weight, increased stiffness, and durability.
Older Models:
Traditionally made of steel.
Known for its robustness and longevity, but heavier and less stiff.
This shift has raised questions about the balance between cost, vibration absorption, and long-term performance.
PROBLEM
Riding over cobblestones subjects bicycle frames to intense vibrations, which can affect both comfort and structural integrity.
Carbon Fiber:
Known for vibration-damping properties.
How does it handle cobblestone vibrations in real-world conditions?
Steel:
Offers robustness and longevity.
How does it withstand the impact of cobblestone riding over time?
This study aims to assess how each material reacts to these conditions and whether resonance could pose a risk during cycling.
ANALYSIS & RESULTS
To evaluate the performance of steel and carbon frames under cobblestone vibrations, both were analyzed using Siemens NX for modal and static analysis.
Modal Analysis:
Identified natural frequencies of the frames.
Both materials had natural frequencies higher than the vibration range of cobblestones, meaning resonance is not a concern.
Static Analysis:
Examined stress distribution and deformation under cobblestone conditions.
Carbon Frame: More flexible, with higher stress concentrations, offering better vibration damping but potential weak points under repeated stress.
Steel Frame: More rigid, with uniform stress distribution, making it more durable but potentially less comfortable.
These results show that both materials handle cobblestone vibrations without resonance issues, but each offers distinct advantages and trade-offs.
OUTCOME
The analysis revealed key differences between carbon and steel frames:
Carbon Frames:
Lightweight and offer excellent vibration damping.
More prone to stress concentrations, potentially creating weak points under repeated stress.
Steel Frames:
Provide greater durability and stability.
Absorb less vibration, leading to a less comfortable ride.
The choice between carbon and steel frames depends on the priority: comfort (carbon) or robustness (steel), which shapes modern cycling technology.