Bicycle Materials Case Study

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

Bicycle Materials Case Study        

Application Requirements

Possible Materials

Physical
Principles

Material Selection

                                                            Conclusion & Future Prospects

                                                            Acknowledgements

                                                            References

Date Written:                                     June 12, 2003

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

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:

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 (Bell’s Aquila-sport helmet).

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.

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 19^th century at least
one-third of all the new patent applications sent to the U.S. Patent Office
were bicycle related. The past 20^th century technical and material
design for bicycles at times increased greater than automobile design. Now in
the 21^st 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.

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/