Bicycle Materials Case Study
Author: Andrew Cantrell
Project Advisor: Professor Tom Stoebe
Project Group Members: Firdaus Khan
Ryan Oakes
Jeread Sines
Table of Contents: Summary
Date Written:
Bicycle Materials Index: Back to Bicycle Materials main page
This senior project is an educational case study on the material science of bicycle wheels, frame, components and helmets. The idea of this bicycle material selection case study is to increase the knowledge of the reader of the case study, as well as the author. We will involve physical aspects of materials (structure, properties, etc.), by educational literature survey, discussions, application analysis, and material selection. This core study will be done in a general way by completing three informative tables. One table will present material properties requirements for the selected materials commonly used for bicycle wheels, frame, components and helmet. Table two will display these common possible materials to be used, in reference to their application (i.e. alloy—frame, foam—helmet, etc). The third table will select the best material for said bicycle application. The material selection will be determined and focused on a cost effective standard touring road bicycle (mid-level) built for the intermediate to advanced road cyclist. Our overall key features will be weight and cost for this mid-level bicycle application. The factor of cost in our discussion will only briefly be examined due to additional manufacturing, design, and material processing costs. The cyclist profile will be exercise minded road bicycle commuters. The correlative material/application processes and materials selection will then be discussed and displayed with conclusions and future prospects. All information presented will be understandable for non- technical audiences.
Topic
Educational case study on
the material science used to in a present day bicycle wheels, frame, components
and helmet.
Goal
My goal for this term project is
improve my ability to investigate a materials science case study and
engineering problem by using my background in physical materials principles.
Objective
The objective of this bicycle
case study is to apply as well as increase my knowledge in applications of
material science, and to present that information to the reader of the case
study.
Approach
This Bicycle
case study will involve physical aspects of materials (structure, properties,
etc.), by educational literature survey, discussions, analysis, and preparation
of a report.
Methodology
The majority of the research
will be done by preexisting educational literature on material properties and
structures. This core study will be done in a general way by completing three
informative tables. One table will present material properties requirements for
the selected materials commonly used for bicycle
wheels, frame, components and helmet. Table two will display these
common possible materials to be used, in reference to their application (i.e.
alloy—frame, foam—helmet, etc). The third table will show the best chose
material selection for said bicycle component application. This materials
selection will then be discussed and displayed and the correlative
material/application processes will then be described.
Outline
Summary
Case Study
Application Requirements
Possible Materials
Physical
Principles
Material Selection
Conclusion and Future Prospects
Significance
The senior project I have
undertaken is a research project on a materials case study for the development
of an educational materials science web site, for Junior High to High School
students. This website is already in place (online) and is designed, authored,
and edited by Professor Stoebe and/or his students; I will add my case study to
it in a reference and informational driven web design including the definitions
that go with my case study. For example, I write about frame alloy design,
composite wheel design, component plastic/metal applications, and helmet
composite design. This case study when presented on the website should peak
some interest, give understanding and encourage growth in the material science
knowledge of its readers.
The following brief case
study outlines bicycle component design through materials selection. In Material
Science Engineering understanding the material selection process is the key to
engineering any application and/or part design. Material selection is the
foundation of all engineering application and design.
As always the major overall bicycle requirements are speed, safety, comfort, and endurance. The bicycle weight is the key to speed, but the lightweight need must be balanced by the other factors (safety, comfort, and endurance). The following table gives a brief outline of the application requirements.
Table 1: Application requirements
Application |
Function |
Wear |
Strength |
Cost |
Weight |
Wheel |
multi-part mechanical performance |
tensile loading |
tensile strength |
21% |
20% |
Frame |
core structure |
stress/strain loading |
tension/compression strength |
49% |
68% |
Components |
moving mechanical parts |
high mechanical wear |
need varies |
28% |
10% |
Helmet |
protect cyclist head |
one use-failure for safety |
impact |
2% |
2% |
Wheels
Wheels are
fundamental to the purpose of the bicycle. A bicycle wheel is made up of a hub,
spokes, a rim, tire, and tube. Each part of the wheel may require different
material properties. Our focus will just consider the materials for the hub,
spokes, and rim. Material importance in comparing these parts of the wheel as
follows:
Table 2: Wheel parts |
||
Part |
Key Feature |
Material Importance |
Hub |
bulky |
low density |
Spokes |
tension loading |
tensile strength |
Rim |
shape |
processing |
Frame
The frame is the core to the bicycle as a complete functional unit. Material selection importance should lay with strength and weight (i.e. strength/density materials and processing). A major consideration is the tube frame design. The standard commercial bicycle frame diagram is show below.
Figure 1: Bicycle Frame [3]
Components
“Components” is the bicycle industry’s name for the moving mechanical parts: everything but the wheel, frame, seat and handle bars. We will just the overall material importance for the components. This focus is the parts function, wear, weight, and cost. The following figure shows some bicycle components.
Figure 2: Bicycle Components [5]
Helmet
The helmet
materials will be considered separately from the other bicycle applications.
The standard helmet design is crushable foams. Helmet design factors are
weight, cost, and safety. An example of standard bicycle industry design is as
show (
Figure 3: Bicycle Helmet [8]
We will only introduce the most common materials that are presently used for these applications. The bicycle wheel, frame, and components materials to be considered are Steel alloys, Aluminum alloys, Titanium alloys, and Composites.
Table 3:
Possible Materials [3]
The Helmet materials lie in a separate material category: Crushable foams. Crushable foams are ideal for helmets designed for one hard impact. Some foam used is EPS (Expanded PolyStyrene), EPP (Expanded PolyPropylene), and EPU (Expanded PolyUrethane). EPS is one of the most common foam used in our society, the white foam found in picnic cooler, eggs carriers, and stereo gear packing. EPP is multi-impact foam, with slow shape recovery, (higher cost) and mostly for multi-impact sports like skateboarding. EPU is similar to EPS, but it has very uniform cell structure that adds to the esthetic appeal. EPS is the most available, cheap, and efficient, thus most common helmet material selection. [7]
The following discussion of physical principles for functional material strengthening will further support the resulting material selection per bicycle application.
We will give a brief outline four of the major physical
principles that can be applied in these applications. The four principles
considered are densification, composites, and alloying. There many
manufacturing techniques used to strengthen and form materials as well.
Densification is the most common and necessary way to strengthen concrete cement composites. In general, this increases the tensile strength by reducing the porosity of the matrix. This can be shown in the functionality of helmet design. The Styrofoam density and porosity must be proportional and functional to protect your head upon serious head impact without injury.
The standard composite rule of mixtures is when the standard matrix is soft/pliable and the reinforcing material is tensile strong. One the major reasons for the prevalent use of composite materials in construction is the adaptability of the composite to many kinds of applications. The selection of mixture proportions can be aimed to achieve optimum mechanical behavior of the harden product. Selection can result in the change of the strength, consistency, density, appearance, and durability.
The alloying of metals is one of the oldest and most fundamental material processing techniques. An Alloy is a solid solution that is composed of two or more elements. There is a solvent (majority composition) and a solute. The Solute element can strengthen the overall solid solution by different element size, density, and other material properties
Given our presented applications, possible materials, and physical principles we can gather our resulting material selection considering with cost and without cost. The factor of cost for the materials is difficult to examine due to lack of presentation in our discussion because vast additional manufacturing, design, and material processing cost/factors.
Table 4: Material Selection |
|
|
Application |
Material w/out
cost |
Material w/cost |
Wheel |
Hub/Rim- Composite, Spokes-Steels |
Hub/Rim- Aluminum Alloys, Spokes-Steels |
Frame |
Titanium Alloys |
Steels |
Components |
Steels |
Steels |
Helmet |
EPP foam |
EPS foam |
This material application selection process as concluded was stated only as a brief outline to demonstrate the need for material science in bicycle technology and not by any means a full discussion.
In the last 10 years of the 19th century at least one-third of all the new patent applications sent to the U.S. Patent Office were bicycle related. The past 20th century technical and material design for bicycles at times increased greater than automobile design. Now in the 21st century even the said “low-class” (inexpensive) bicycles are pushing boundaries of lightweight, efficient, functional, and high performance needs of the cyclist.
In conclusion, we could say that bicycles have a big future due to their increasing popularity of use; thus material selection and design will lead that future in terms of technology. Low environmental impacts have been added incentive for present popular use in contrast to the automobiles for commuting. But as always, popular use is driven by utility of cheap efficient exercise and transportation.
Figure 4: Energy cost of Transportation [5]
This report has renewed my
direction in my senior project by broadening the scope; characterize tasks, and
reminding me the importance of literature review. My future prospects are to
organize this report into web pages and add broader content (i.e. list more
materials, applications and define costs).
I acknowledge the following instrumental people for their help:
Professor Raj Bordia, thank you for directing me to
succeed in this course as well as in my Material Science degree and curriculum.
Professor
Mehmet Sarikaya, thank you for putting aside
your schedule to meet with me and help focus my discussion about my senior
project topic and materials.
Professor Stoebe, thank you for being my senior project adviser
and providing an opportunity for my case study topic in informational driven
web design.
1
Bicycle Wheel
Manufacturing and Composition
Author(s): Al Fernandez, Jen Leicht, Scott Radcliffe, David Roberts, Lan Thomas, Tom Triesenberg, Song Vufang, LoToya Waters
Publication: MSM 481 - Bicycle Manufacturing Project Reports
Website: http://www.egr.msu.edu/msm/dept/KWON/
2
Drive
Systems
Author(s): Brahms, Driscoll, Gilbert, Masterson, McKenzie, Mooradian, Myers, Tedeku
Publication: MSM 481 - Bicycle Manufacturing Project Reports
Website: http://www.egr.msu.edu/msm/dept/KWON/
3
Bicycle Frame
Author(s): Mananger: Brian VanDragt, Assistant Manager: Sherri Defever, Engineers: Kristin Brandenberg, Rebecca Herman, Jeremy Doezema, Shanti Oram, Wilson Faust, Matt Saltzgaber
Publication: MSM 481 - Bicycle Manufacturing Project Reports
Website: http://www.egr.msu.edu/msm/dept/KWON/
4
Bicycle History
Author(s): TDK site created by 4UIMOW lawncare * Ronnie
Gallimore
Website: http://tourdekale1.tripod.com/tourdekale/id18.html
5
Science of Cycling
Title: What is the Science of Cycling?
Website: http://www.exploratorium.edu/cycling/index.html
6
About, Inc. (About.com) Copyright
2002
Title: Applications:
Bicycles (Guide picks)
Website: http://composite.miningco.com/cs/appsbicycles/
7
Bicycle Helmet Safety
Institute
Title: Foams Used in Bicycle Helmets
Website: http://www.bhsi.org/foam.htm
8
Title:
Website: http://www.bellbikehelmets.com/main/product/aquila.htm
9
Materials Science and
Engineering Fifth
Edition
Author(s): William D. Callister, Jr.
Published: John Wiley & Sons., Inc. Copyright 2000
10
Materials and
Processes in Manufacturing Eighth
Edition
Author(s): E. Paul DeGramo, J. T. Black, Ronald A. Kohser
Published: John Wiley & Sons., Inc. Copyright 1999
11
Physical Metallurgy
Principles Third
Edition
Author(s): R. E. Reed-Hill and R. Abbaschian
Published: PWS Publ. Co.
12
Complete Guide to
Bicycle Maintenance & Repair
Author(s): Jim Langley
Published: Rodale Press Inc. Copyright
1999
13
Zinn & The Art of
Road Bike Maintenance
Author(s): Lennard Zinn
Published: Velo Press Copyright
2000
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