Materials Selection And Manufacturing Processes For Bicycle Fork Component

Function of Bicycle Fork Component and Material-Based Attributes

Questions:

1.Describe the function of the component, clearly identifying the material-based attributes that are important to its function?

2.What are the material property constraints and objectives that would be required (you may use assumptions for the exact values of these properties?

3.Identify what materials could be used for the component, and then to ultimately identify what you consider to be the best choice?

4.Identify all of the manufacturing processes that could be used to make that component?

1. A bicycle fork is a component that supports the front wheel. Its main components include the two blades that join to hold the front wheel in place, the crown joints the two blades at the top. The crown is then connected to the steerer tube. The tube functions to support the fork and enhance the support of the handlebars. The steerer connects to the frame through a combination of bearings that are referred to as headset and they are connected to the head tube. The function of the bicycle fork is to hold the front wheel in place (John1989, p. 6).

The material based attributes put into consideration during the manufacturing of the bicycle fork include: Ductility, this factor enables the material used in manufacturing to be easily shaped into desired shapes without affecting its strength through the tensile forces. Durability of the bicycle fork was considered too in the manufacturing of the forks. The durability functioned to ensure that the loss of strength was significantly reduced. Reliability was also considered during the manufacturing process (Hurst 2013, p. 72). It helped to ensure that the material used could sustain adverse effects that never exceeded the elastic limit.

2. The most commonly used materials in the manufacturing of the bicycle frame include: aluminium, steel, carbon fiber and titanium. Aluminium, steel and titanium have a unique combination of attributes that are important in this discussion. Steel is made up of twice the density and tensile forces of titanium. Steel contains 2/3 of the density of aluminium and 2/3 of the strength of aluminium. This concludes that forks manufactured using aluminium and steel should have a similar weight. Steel contains 2/3 of the strength from aluminium. Considering the weight of aluminium to steel, one will require thrice the portions that will be used by steel to make an aluminium one. The volume (cubic) of steel is 2/3 of the same volume of aluminium given that the weight is constant (Elena 2009, p. 34). In manufacturing of bicycle forks, engineers are challenged when designing the bicycle forks. They have to ensure that the bicycle forks become slightly thinner as the diameter remains constant. It is advised that the thickness of the frames should be 0.4mm. A decrease in this could be disastrous as the fork can easily buckle out and due to the weight and terrain, vibrations will increase, reliability will be compromised and hence denting will occur. The tensile forces will exceed as the thickness will not be able to stop it from reaching the elastic limit.

Material Property Constraints and Objectives for Manufacturing

Constraints that are considered during the selection of the material to be used during manufacturing process include stiffness so that they have the ability to resist tension, have enough strength, ability to withstand adverse stress, the rate of conductivity, the rate at which it can resist electrical conduction, relatively high price is incurred during manufacturing and the weight is relatively high. The objectives that are considered during manufacturing include: ensuring that the cost of production is low, ensure that the weight is low, reduced volume of material used, low impact to the environment, quick heat loss and increased energy reservation (Michael 2013, p. 93).

When manufacturing the bicycle forks, it is important to consider the fatigue constraint that the bicycle will be challenged through during its usage. Steel is hardly affected by fatigue. It can endure any stress that is applied to it over a long period of its usage. On the other hand, aluminium hardly endures the fatigue that is applied to it. This explains the reason as to why it is important to build it with extra strength, 2/3 or what is used in steel. Durability as a constraint in the manufacture of the bicycle fork is also considered. This aims at giving the value for money in the selling by recovering the cost of production (Gwo-Hshiung 2016, p. 69).

3 .Consider these attributes, constraints and objectives in undertaking a basic material selection using level 2 of the CES software to initially

In carbon fiber, the material used has advantages of being light in the overall weight, it absorbs shock better compared to aluminium, it is relatively durable compared to aluminium and the ease of manufacturing it is relatively good. It is disadvantageous in being expensive to manufacture and it is unfixable when it gets damaged (Matt 2012, p. 116).

Aluminium has a light weight, resistant to rust, cheap in purchasing hence reduced cost in manufacturing, it is stiff hence being durable and it lasts for a reasonable period of time. It is disadvantageous due to its reduced strength when compared to steel and has the shortest fatigue life when compared to steel carbon fibre and titanium. Titanium is merited due to its reasonable weight as it is easy to handle, it hardly fails or reduced mechanical conditions will affect it and it is free from corrosion. However, its strength is relatively low than steel and its relatively heavy when compared to aluminium (Peter 2005, p. 1001). Steel has a high tensile strength and has a long lifespan when compared to the above. Its demerit is due to its weight that is considerably high and its ability not to resist corrosion.

Materials/Properties	Young’s modulus	Cost	Fatigue Strength at 10^7
Carbon fiber	150 GPa	44.5 $US/kg	300 Mpa
Aluminium	82 GPa	2.49 $US /kg	157 Mpa
Titanium	120 GPa	26.2 $US /kg	600 MPa
Steel	217 GPa	0.664 $US /kg	700 MPa

Information in the table was taken from CES program. However, steel has the cheapest price and it actually has a high young’s modulus, as a result I will choose the steel as it is also one of the common materials for manufacturing bicycle forks (Ces Software).

4. Based on the material you ultimately selected in question 2 for your component, use level 2 of the CES software to identify all of the manufacturing processes that could be used to make that component.

Identification and Selection of Bicycle Fork Materials

Steel production process contains steps that are involved during the manufacturing process. Iron making is the initial process that involves blasting the raw materials to get the molten steel that can be molded into various shapes of the bicycle fork. The primary steel making process is the second stage (Harrison 1979, p. 23). It uses oxygen that is pumped into the metal to remove carbon. The secondary steel making process involves trying to purify the molten steel. This can be achieved through addition or removal of components that make up the composition of steel. This includes stirring, ladle furnace, ladle injection, degassing and adjusting the composition of the molten iron by blowing oxygen through it. The continuous casting process involves molding the molten steel into thin shelled structures so that it can solidify. After solidifying, the tubing’s are reduced into the desired lengths according to the specifications. Primary forming involves shaping of the cast steel into different shapes according to the specifications of the bicycle fork (Clifford 2013, p. 39). Finally, the bicycle fork is manufactured, fabricated and the exterior decoration done to attract the clients. The process of manufacturing includes: shaping, drilling, welding, galvanizing, tempering and carburizing.

Choose two of the manufacturing processes that could be used for your component and explain why you believe them to be most suitable (clearly state any assumptions you have made to reach your conclusion (Welding and brazing)

The molded parts that have been molded above are now ready to be used in the manufacturing of the fork. The parts will be joined together to make the fork. The blades will be fitted to the stem. The stem will be connected to the steering tube and then welded together to form the bicycle fork (Malcom 1995, p. 13). On the other hand, legs also welded to the blades and also brazing the crown. However, it is required to drill a hole close to the fork blade’s end for air expanding to run out during the brazing and welding processes. Finally, they are painted and polished as required

Find a resource/s online that details/outlines the key equipment and steps involved in each of the two processes. Use this to construct a process map or flow chart for each manufacturing process.

 Resources required in the production of steel include: cast iron, coke and lime which are heated in blast furnaces to melt them.

The process involved in welding involves connecting the components that had been manufactured from the cast iron. The tubing is achieved through being butted using the mandrel and die. The butted tubing is hydro formed to fork blade geometry. It is then annealed at 865⁰c before being oil quenched. It is then back tempered at 570⁰c before cooling at room temperature (Davis 1992, p. 28). It is then shipped.

Brazing is a process that aims at strengthening the metals that have been combined (Sharma 2007,p. 34). Resources required during brazing include the filler, additional metal and a furnace that will be used to heat the metals and the filler together. The joining must adhere to good fitting that will enable proper capillary to take place. The metals will then be cleaned so that capillary will take place. The parts will then be fluxed before the metal will be assembled for brazing. After brazing, the area is cleaned so that it can obtain a clean surface area (Joseph 2001, p. 309).

Use Microsoft excel and the cost equation below to construct a plot of the cost per component versus the number of components for both of the manufacturing processes for a range of production volumes from 1 to 100,000..     

Identify which of your processes is the most cost effective for the range of production volumes examined

The cost per unit as per ces software,

Carbon 44+315/5+210/12 = $124.5

Titanium 26.2 + 315/4 +410/12 =138.2

Aluminium 2.49+ 315/5+210/12= 83.0

Steel 0.664 +315/6+210/13= 69.4

Steel is the most effective metal to be used in the manufacturing of the bicycle fork. It is readily available. The molding is easy as the equipment to mold it is readily available. It is highly durable as compared to titanium aluminium and carbon fibre. Steel has a high versatility compared to the other materials that were used to manufacture the bicycle forks (Kenneth, p. 113).

Calculate the impact of doubling the production rate for a production volume of 10,000 components. Suggest and briefly explain one practical method to significantly increase the production rate of your process without the need to buy additional capital equipment

Impact of doubling the production rete of a volume of 10000 components. The production rate can be increased by increasing the time that has been allocated for the manufacturing of the bicycle forks. The rate can also be increased by increasing the number of items that are supposed to be manufactured. This is facilitated by the discount that is given when the load being produced is relatively high compared to when one manufactures a few pieces of the bicycle fork. Application of modern technology e.g. the blast furnace instead of the traditional incinerators helps in reduction of cost of operation (David 2006, p. 332).

Using the table provided by Ces, we will increase the production rate by 10.000

Materials/Properties	Young’s modulus	Cost	Increased production rate by 10000
Carbon fiber	150 GPa	44.5 $US/kg	445000$US/kg
Aluminium	82 GPa	2.49 $US /kg	24900$US/kg
Titanium	120 GPa	26.2 $US /kg	262000$US/kg
Steel	217 GPa	0.664 $US /kg	6640$US/kg

References

Ces software.Clifford S. Russell, William J Vaughn 2013:, Steel production processes, products and residuals.

Second edition.Davis A. C. 1992:, The science and practice of welding.David O. Whitten, Bessie Emrick Whitten- 2006:, the birth of bid business in the United States.

Second edition.Elena R. Dobrovinskayaa, Leonid A. Lytvynov, Valerian Pishchik:, 2009 sapphire: Material Manufacturing applicationGwo-Hshiung Tzeng, Jih-Jeng Huang 2016. Fuzzy Objective Decision MakingHarrison T. S. 1979. Handbook of analytical contro of iron and steel production.

Hurst Robert 2013:, Bicycle commuter handbook. Second edition, a structured approach to design and manufacturing.John Marino, Lawrence May, Hal Zina Bennett, 1983: John Marino’s Bicycling book. https://books.google.com/books

Joseph R. Davis 2001:, copper and copper alloys. Proceedings of the third international brazing conference.

Kenneth Warren 2001.:, Big steel: The first century of the United States steel corporationMalcolm Blair, Thomas L. Stevens 1995:, steel casting handbook, sixth edition

Matt Seaton 2012:, Two wheels: Thoughts from the bicycle lane. Composite engineering handbook.Michael F.

Ashby, Hugh Shercliff David Cebon 2013:, Materials: engineering, science, processing and design.Peter Morgan, 2005:, Carbon fibers and their composites. https://books.google.com/books Sharma P. C. 2007. Production technology. (Manufacturing processes and brazing)