• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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• pp.130-137
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• 2003

The pipe of CFRP for bicycle frame is designed and made for light weight of bicycle and then its suitability to bicycle frame is verified by comparing the other material i.e. steel, Cr-Mo steel, Al alloy pipe for bicycle frame. The pipe of CFRP is laminated to [0/$\pm$45]$_T$ and made by tape winding method and then its degree of light weight is evaluated by comparing the other pipes which is made by steel etc.

• Journal of the Korean Society for Precision Engineering
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• v.34 no.2
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• pp.139-143
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• 2017

Finite element analysis was performed for a split-type CFRP bicycle frame, which was designed to apply a compression molding process with carbon fiber prepreg for a conventional bicycle. An epoxy adhesive material for joining the frames was selected by the extent of stress at joint interfaces. The split-type bicycle frame was then formed and its weak parts examined by the boundary conditions according to reliability tests. The results verified the reliability of the bicycle frame after modification of these weak parts. The finished product was manufactured by using this developed split-type bicycle frame.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.6
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• pp.271-276
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• 2018

Based on the service design processes, we examined the market conditions and the criteria to be considered in selecting materials and selected CFRP CNT materials in the development of bicycle design. This material was used to develop frame design among the bicycle parts. The bicycle frame, designed with CFRP CNT material through vibration attenuation testing, tensile strength testing, and stiffness test results before prototype production, shows better results than the bicycle frame manufactured with conventional CNT materials in terms of function.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.6
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• pp.93-100
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• 2013

This paper presents the development process for a bicycle monocoque frame using bolt fastening. Traditionally, bicycle frames have been constructed with metal tubes joined at their ends by welding. These frames have been brazed or soldered onto metal lugs, forming the frame. Because stress loads become greatest at the joint of the bicycle tube frame, joint construction strongly influences frame design and construction. To avoid the inherent problems of material discontinuity at frame joints, numerous designers have attempted to reduce or eliminate the number of joints in tube frames. Nevertheless, the manufacture of high quality, reliable, one-piece and jointless frames has proven difficult and expensive. In this study, a new monocoque frame adapted to a hybrid bike is proposed. The advantage of the monocoque frame, is theat is has a rechargeable battery system that is built into the frame; as a result, the emotional quality for the customer is improved. In order to estimate the design compatibility compared with that of tube frames, structural analysis is performed using finite element method. A prototype based on a modified design has also been made and stability testing has been carried out.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.6
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• pp.51-58
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• 2021

The notion of leisure has changed with industrial development and improvement in life quality. Bicycling is a healthy sport; it is an exercise performed while enjoying nature. There have been many changes in the materials that are used to manufacture the bicycle frame. Iron and aluminum have been mainly used in bicycle frames. However, carbon-based materials are lighter and stronger than metal frames. The bicycles made of carbon composite changes frame rigidity depending on the direction of the carbon sheet sacking angle. We study the direction of composite material and how they affect the stiffness of frames based on the stacking angle.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.4
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• pp.178-185
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• 2017

Carbon fiber frames are actively developed for developing carbon fiber frames as the material of the next generation of bicycle frames, and are currently being developed with carbon fiber frames, hardness, shock absorption, light intensity, and strength. The carbon fiber bike models require a premium, differentiated design concept, which is essential to the development of a conceptual and differentiated design, requiring the development of essential structural structures, safety and refinement, and more of their own identity. In this study, a personal and unified image was derived from the research of the needs of consumers and image analysis process and then in the practical design work, the road bike bicycle frame design was proposed targeting the frame on the basis of carbon fiber materials.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.2
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• pp.147-156
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• 2016

In this paper, optimal designs of bicycle frame were studied for weight reduction of bicycle using carbon-fiber-reinforced plastic (CFRP), glass-fiber-reinforced plastic (GFRP) and Kevlar-fiber-reinforced plastic (KFRP), respectively. Based on the anisotropic properties of FRP material, stacking angle and thickness optimization were performed under the safety reference of European committee for standardization (CEN) to ensure the stability of bicycle frame. Finally, performances of FRP bicycle frame was evaluated by digital logic method based on the optimized results of weight, strength properties and cost. Then, the optimized bicycle frame composed of each FRPs were evaluated and ranked by total performance values.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.6
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• pp.466-471
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• 2019

Road photovoltaic power generation is a technology that combines photovoltaic power generation while maintaining the function of the existing road by installing special photovoltaic modules on it. In this paper, we developed three types of modules and structures suitable for sidewalk blocks and element technology for the development of a solar road module for a sidewalk and bicycle road. The road solar potential in Korea is 10 GW. After analyzing the daily data obtained after the construction of a 10 kW solar road testbed, it was found that its utilization rate compared to the general photovoltaic energy is 80%.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.1
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• pp.121-127
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• 2013

With the continuing demand for lightweight bicycles, carbon fiber composite materials have been widely used in manufacturing bicycle frames and components. Unlike general isotropic materials, the structural characteristics of composite materials are strongly influenced by the staking directions and sequences of composite laminates. Thus, to verify the design process of bicycles manufactured using composites, structural analysis is considered essential. In this study, a carbon-fiber-reinforced plastic (CFRP) bicycle frame was designed and its structural behavior was investigated using finite element analysis (FEA). By measuring the failure indices of the fiber and matrix under various stacking sequences and loading conditions, the effect of the stacking condition of composite laminates on the strength of the bicycle structure was examined. In addition, the structural safety of the bicycle frame can be enhanced by reinforcing weak regions prone to failure using additional composite laminates.

• Transactions of Materials Processing
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• v.28 no.1
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• pp.15-20
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• 2019

The superplastic forming/diffusion bonding process has been developed to fabricate a core frame structure with joint nodes out of tubes, for the development of a titanium high performance bicycle. The hydroforming process has been applied for bulging of a tube in the superplastic condition before, and during the diffusion bonding process. In this experiment, a commercial Ti-3Al-2.5V tube was selected as raw material for the study. The forming experiment has been performed using a servo-hydraulic press with a capacity of 200 ton. Next, nitrogen gas was used to acquire necessary pressure for the bulging and bonding of the tubes to fabricate the joint nodes. The pertinent processing temperature was $870^{\circ}C$ for the superplastic hydroforming/diffusion bonding (SHF/DB) process, using the Ti-3Al-2.5V tube. The bonding quality and the progress of bulging and diffusion bonding have been observed by the investigation of the joining interfaces at the cross section of the joint structure. The control of the nitrogen pressure throughout the SHF/DB process, was an important factor to avoid any significant defects in the joint structure. The whole progress stage of the diffusion bonding could be observed at a joint interface. A core structure with 5 joint nodes to manufacture a titanium bicycle could be obtained in a SHF/DB process.