Design Report – Foldable Bicycle (2024)

Design Report –
Foldable Bicycle

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Table of Contents
1. Introduction..............................................................................................................................2
2. Requirements Analysis.............................................................................................................2
3. Functional Analysis Systems Technique (FAST) Diagram.....................................................4
4. Quality Function Deployment (QFD) Diagram.......................................................................5
5. Product Design Specification to BS7373 (PDS)......................................................................7
6. Illustration of improved sustainability.....................................................................................9
7. Development and description of initial concepts...................................................................10
8. Systematic selection of preferred concept..............................................................................12
9. Consideration of material, manufacturing, cost.....................................................................13
10. Conclusion..........................................................................................................................16
References......................................................................................................................................17
Appendices....................................................................................................................................19

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1. Introduction
In order to lower down the negative impact on the environment, regular efforts are in process for
the designing and manufacturing of sustainable products. It is particularly necessary since the
number of automotive vehicles has largely increased on the roads. Their carbon footprints can be
reduced greatly via sustainable transportation and mobility. For sustainable mobility, the folding
bicycles act as a major tool since they are stronger, lighter and can be folded up smaller.
Travelers will find these bikes to be the best. These can be easily transported on the public
transportation systems owing to their simplified functionality. In order to develop such a frame
of folding bicycle which is very simple to carry (just like a small-sized suitcase), it's necessary to
have crucial attachments and folding mechanisms. The project report discusses the requirement
details of the foldable bicycle. Then the insights of functional analysis are discussed. Also the
findings of QFD, production design specification are discussed.
2. Requirements Analysis
The recent market surveys have indicated that the normal bicycles are very heavy, not much
compact and cannot be carried by the traveler to different far off locations easily. This causes the
traveler to depend on local transport. So, this difficulty has necessitated the innovation of
foldable bicycles as an alternative to traditional bicycles. (Pirnat, Savšek and Boltežar, 2011)
However, another field survey has indicated that despite the market having foldable cycles, they
have been found to be less portable. The major reason behind this has come out to be the
complex foldable configuration which causes issues in transporting it. This has necessitated the
development of such a new foldable bicycle which has weightless material and is highly
portable. This work directs the above-mentioned problem with the proposal of a new foldable
bicycle design which easily curbs the issues prevailing in the current design. (Shelke, 2018)
There are numerous reasons as to why bicycles are referred to as the greatest invention by the
human race (McEwen et al., 2018). For example, they help in keeping the air fresh (thereby
preventing global warming), maintaining good health (20 min bike ride acts as an excellent
cardio exercise thus helping in fat reduction and strengthening of the cardiopulmonary

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functions). Further, not much space is needed to run bicycles i.e. 6 bicycles can take the place of
a single car on road and 20 bicycles can replace a car in a parking lot. Also, they are highly cost-
effective as a bicycle only costs one-hundredth of a car’s cost (Breach, M, 2009). Nor requiring
gasoline, they also do not attract any taxes. When compared with cars, bicycles turn out to be
highly affordable for poor people all around the globe. Bicycles are highly resource-effective
since not much raw material is required to develop a bicycle. Lastly, bicycles can be used by
both children and adults (Cross N, 2008).
In order to make the bicycle easily transportable, it must be foldable. The folding body frame
will act as the key supporting element which supports the wheels and other components of the
bicycle. The safety bicycle, having 2 triangles (a main and other paired rear), presents the best
and modern frame design with respect to an upright bicycle. (M, Prakash R and R, 2014) This
frame is famous by the name of the diamond frame. To render the bicycle strength, stiffness, and
low weight, numerous materials and shapes are amalgamated. When the folding bicycle is
folded, the main frame is folded in such a way that the horizontal axis of both the wheels reaches
the same axis. When the main frame gets folded up completely, Velcro is used to fix the holder
of both the wheels together.

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Apart from offering a structure to the bicycle, a bike frame also plays the role of a load-bearing
body. (Hyeong, Roh and Kim, 2016) Depending upon its material and /or design, it is capable of
handling a certain amount of load. Also, a varied configuration will lead to a varied orientation
and magnitude of the load. The safety factor (i.e. minimum twice the max. stress that the bike
might be needed to undergo at any point in its operation) is one of the basic factors to be
considered while designing the frame of the bike.
3. Functional Analysis Systems Technique (FAST) Diagram
Functional Modelling can be known as the establishment of functional structure in regards to the
product of interest. (Hong, Chun and Choi, 2014) When the recent inventions or technologies are
to be utilized, the traditional method-based solution designs to not tend to offer the needed
design. A list of the necessary constraints and needed functions must be used for expressing the
core of the problem. A simplified black box diagram, as well as a functional tree of the foldable
cycle, has been showcased by the given figure. The functional tree which has been created on the
basis of the need statement. The literature survey as well as the small field survey has been used
for gaining the need statement.

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The Functional Analysis System Technique showcases the logical relationship which exists
between the foldable bicycle’s functions. (HE and YIN, 2019) This helps in finding out the
project’s scope as well as having objective thinking regarding the problem. The participants are
enabled to find out all the needed functions once the functions are organized into a function-
logic, FAST diagram. The below given FAST diagram helps in verification of if, and
demonstration of how, the project’s needs can be gained via the suggested foldable bicycle
design. It also helps in finding out the functions which are unimportant, missing or copied.
4. Quality Function Deployment (QFD) Diagram
Quality Function Development can be known as a set of tools and process which helps in the
effective definition of the consumer needs and conversion of them into in-depth engineering
plans and specifications for the production of such products which help in achieving those needs.
The design project makes use of the QFD so that the customer requirements can be translated
into design targets which are measurable. (Covill et al., 2016) This is followed up by moving
them from the assembly level through the sub-assembly, component as well as production
process levels. A standard set of matrices used for this progression facilitation is offered by the
QFD methodology. An organization’s success highly depends on Effective communication. QFD
helps in communicating the various customer needs (including quality, production, sales, design,
marketing) to numerous business operations in an effective manner. The organization is enabled
(by Customer’s Voice effective communication) to work together so that such products can be
produced which offer high customer satisfaction.