Analysis of Carbon Fiber Bikes

Introduction

There are many suggestions and criteria for choosing the right bike for your needs. The most notable is: “the best bikes are carbon fiber ones” I planned to look into the extent of which the material used affects the bike.

The aim of my essay was to determine the effects of the different materials used on the bike and the user as they are complementary. I researched this by interviewing bike experts at the Professional bike shops around Mauritius. I also did some practical experiments in the DT lab at my school whereby testing sample of different materials against a range of criterions thereby giving me a vivid way of testing. Although the experiments were not exactly like driving a bike through the preset conditions, they mimic the conditions and therefore it is appropriate to use in the study. With Multinationals in Mauritius engaging themselves in cycling activities to promote welfare or to raise capital for charity or another cause. Such as Deutsche Bank Cycle Tour, Vistra Cycle Tour ,etc. This has opened more people to cycling activities as they can participate for a small fee. Furthermore, due to this,somethus, professional bike shops have decreased price and have special promotions to enable more people to buy bikes as they see that there is the demand in the market. However there is a famous concept amongst amateurs and some professionals that carbon fiber bikes are the best bikes to buy even though they are more expensive. Bike shops use this concept to their advantage to persuade customers to buy these bikes as they are more expensive. I, myself am very keen cyclist and like to participate in numerous events, therefore the importance to find out if carbon fiber bikes are really the best bikes is paramount.

 

Why Cycling?

Cycling has many benefits, both to the society and to the individual. Some examples are:

Pollution: Cycling helps reduces CO2 emissions as the bike relies only on your legs and body to operate and does not require any form of fuel such as diesel, electrical energy,gasoline,etc. It is estimated that cycling saves over 16 million tons of CO2 in the European Union. This helps our environment that is already suffering from global warming as it significantly reduces air pollution. Air pollution is a big factor contributing to lung problems and other sicknesses which causes death. Furthermore, it also reduces other types of pollution such as noise pollution as it is less noisy than a motor vehicle and it reduces land pollution as cycling paths require less land the motorways and main roads that usually have more than 4 lanes. It is also estimated that cycling saves between 500 to 5.630 million euros in Europe, this of course depends on the social cost of carbon.

2. Resources: Resources are finite, which means that there is limited amount of resources available on our planet. According to www.ecf.com, On average, a car in the EU in 2017 was around 1.4tons compared to a bike which was barley 20 kg, which would represent about 1.5% of the weight of a car.This shows us that fewer materials and resources are needed to produce bikes than cars, which makes it more economical in terms of resources.

3.  Health and Well-being: It is said that riding a bike increases your standard of living interns of health. It contributes to longer and healthier lives as cycling itself is an exercise and has many positive effects on the human body. It helps prevent numerous serious and deadly illnesses such as: Osteoporosis, some types of cancer, many cardio-vascular diseases, etc. it also helps to prevent and fight against other non physical illnesses such as psychological illnesses.  It has been shown that cycling may also contribute to reducing Alzheimer’s and other sicknesses such as cognitive decline. As a sport it may also help fight against depression.

Get Help With Your Essay
If you need assistance with writing your essay, our professional essay writing service is here to help!
Essay Writing Service

4. Tourism and the economy: In my country, Mauritius, we have a market for bicycle tourism, with hotels and other holiday firms offering tourists and locals the opportunity to visit the island on mountain bike. This contributes to the tourism and also the economy of the country as this trend is growing rapidly due to the good quality of the mountain bikes and as the bikes are mountain bikes, it adapts to the different terrains and tourists can visit multiple locations of different terrains easily, thereby increasing the attractiveness of the experience.

5. Logistics, Business and Commerce.: In Mauritius, the logistics is faster through medium of 2 wheel vehicles. As the island has seen an increase in traffic caused congestions and other problems, therefore most of the Mauritius Post’s vehicles are bicycles and motorcycles, however they are reducing their motorbikes and re introducing new bikes as to reduce their carbon footprint as a “green” initiative.

 

 

 

Bike Terminology

There are 2 types of bikes : Mountain Bikes MTB and Cyclist Bikes

carbon fiber bike refers to CFRP

Mountain bikes

A Mountain bike (MTB) is a bike specially designed for off road cycling activities

They have front or full suspension, bigger tires for grip, etc. These bikes can be used off road and on road as cyclist bikes.

 

Bike frame

 This is the chassis of the bicycle and is the support where all the parts are mounted on, it is the centerpiece. It is composed of the following:

•              Top Tube  

•              Down Tube  

•              Seat Tube  

•              Chain-Stay  

•              Head Tube Fork  

•              Seat Stay Wheels: This is the 2 wheels where the bikes revolve from. It is the 2 pieces that are in contact with the Road and its conditions. They are composed of these parts:• Rubber outer tire• Inner Chamber • Rim• Spoke • Hub Power Train: This is the part that transfers manual power (peddling) to rotational power. It is composed of the following:• Chain Ring• Chain • Free Wheel Cassette

•              • Derraileur• Pedal• Crank.

(Bicycle Riding, 2019)

Materials and Characteristics.

I will go through 3 of the most used materials in mountain bikes and explain what exactly it is and also some of the properties associated with this specific material.

Carbon Fiber: At the molecular level, carbon fiber is a bunch of carbon atoms

That are bonded together to form a sort of chain. The fibers are strong, lightweight and very stiff. It is universally used in building many things such as motorcycle parts and protection devices. It is most commonly provided in the

form of a cloth like mats , similar to glass fiber. the resulting object built with

The fiber has high tensile strength , is very lightweight.

DISADVANTAGE: Expensive

2.  Mild Steel : mild steel is one that has a steel carbon content of 2.1% per weight. It is the most commonly and widespread used steel as it is relatively cheap compared to other forms of the metal. It is both malleable and ductile. It is the best choice for many structural applications, as failure by yield is not a risk.  

3.  Aluminum is a soft white silvery, nonmagnetic and ductile metal in the boron classification. It is the third most abundant element after oxygen and silicon. Making is relatively inexpensive. It is also very light making it ideal for bike frames. It has a very low density and has the ability to resist corrosion .

Prediction and hypothesis

The aim of my experiments is to test a tube and sheet of each material respectively, this is done in order to mimic real world conditions with respect to riding a mountain bike. This will enable me to give a reasoned conclusion in order to    In the strength test, I predict that the carbon fiber will be able to withstand more under the hydraulic press than the mild steel and the aluminum. For the Malleability test, I predict that the softest material (aluminum) will easily damage. As for the corrosion test, I think that the steel will rust as it is not treated and its low carbon content.

 

The Test

The experiments are designed and conducted under classroom conditions to test the differences between  materials in terms of strength, malleability, anti corrosion properties,( main factors that would influence a cyclist to choose material for his/her bike)., tubes of mild steel, aluminum, and carbon fiber.

, Therefore it will not be as accurate as a profession laboratory as research institutes, as the facilities and equipment/machines are not the same in terms of accuracy and also the variety of specialized testing and manufacturing machines.

Strength Test:

A hydraulic press is a machine that uses a hydraulic cylinder to create a compressive force that is in turn used to compress objects. It relies on Pascal’s principle. It is mainly used for manufacturing operations such as moulding, punching, forging and clinching amongst others. Each respective tube has been put under the manual hydraulic press and physical change has been observed with a constant amount of pressure measured in (BAR).

Mild steel and aluminum both showed an increase in temperature compared to the carbon fiber tube which showed little to no drastic increase in heat. The aluminum tube was crushed under the pressure and visible wear and tear was noticed. The steel tube did not tear like the aluminum but got folded when compressed. Whereas, disappointingly, the carbon fiber tube became crushed into fibers and powder much more easily than the much thicker steel tube.

TUBE

Heat present?

Physical Change

Aluminium

yes

torn and crushed

Steel

yes

 compressed& flattened

CFRP

no

crushed, powdery like structure with exposed fibers

Malleability (hammer test)

For the hammer test, the respective tubes have been secured on an engineers vice and then

I will hit them at the middle of the tube and other places  multiple times to mimic the accidental damage when falling down. It is noted that the aluminum tube is most easily damaged and incurs many dents and damage. The mild steel tube incurs less damage and incurs only scratches and nearly no dents. The carbon fiber tube does impressively well with no much visible damage except from a few scratches. This shows that the carbon fiber tube is more resistant to damage of accidental nature.

Corrosion/rust Test

The respective tubes have been placed in containers of water for around 4 months.

The Mild Steel tube has rusted due to its low carbon content, The aluminum tube has not shown any significant sign of water corrosion/rust damage. The carbon fiber tube also does not show any sign of water corrosion/rust damage.This shows that carbon fiber and aluminum based bikes are least likely be damaged in moist conditions(rain,excess humidity, etc).

LIMITATION OF THIS EXPERIMENT: Rust in steel can be prevented with paint, that said, if there are deep scratches in the paint coat that exposes the metal to the moisture, it can have adverse consequences on the steel.

Bend test

For this test, sheets of 1 m x 1 m of each of the respective materials have been taken and have been bent with the help of a hydraulic press with the sheets placed on supports on each side as to create an arc when bent. The steel sheet was the hardest to bend compared to the aluminum which was fairly easy. The carbon fiber was more brittle and stiff compared to the aluminum but did bend easier than the steel sheet.

Speed Test

For this test, I have asked a few friends to help me and the experiment was set up as follows:

 Carbon fiber bike vs  a mild steel bike vs an aluminum bike . This was on a rocky hillside terrain and they all started at the same time. The arrival time was  taken using a stopwatch.

Carbon fiber bike vs  a mild steel bike vs an aluminum bike . This was on a regular asphalt terrain and they all started at the same time. The arrival time was  taken using a stopwatch.

In this experiment, it has been seen that the aluminum  mountain bike has arrived before the carbon fiber and lastly the steel one.

 LIMITATION OF THIS EXPERIMENT:  Human error factor; It is difficult to ascertain if each rider is riding at the same speed and also the strength and endurance of each rider can be different .Furthermore, a professional lab test could have used to get more standardized conditions and results, however this is very costly.

Bike Type

time taken for rocky terrain

time taken for asphalt terrain

CFRP Bike

5min45 seconds

4mins

Aluminum Bike

6min12 seconds

4mins 44 seconds

Steel Bike

10min20 seconds

5mins 13 seconds

Conclusion

 A single answer cannot be pinpointed as each material has its own pros and cons as well as the results in the different experiments, this shows that the choice of materials used affect the performance in its own way, however when we are talking about performance, it carries as each individual has his own needs and factors to consider when choosing a bike. Therefore it is difficult to ascertain the performance as it depends on the individual riding the bike and the environment/context the rider is in. That said, it is noted that carbon fiber bikes are lighter and more resistant to water damage and falling damage. This could be a good choice for a pro cyclist who cycles on asphalt surfaces even in rain and if he falls down, the bike may not be as damaged as an aluminum bike. In this case, his performance may be better with a carbon fiber bike than with a steel cycling bike which is heavier and more prone to water damage. However based on the experiments I have conducted, it can be seen that the CFRP bike is faster on both surfaces. It also does not rust nor corrode which prolongs its lifespan and preserves its performance. It also demonstrated good shock resistance as seen in the hammer test which  makes it very good and doesn’t deteriorate its physical performance. Therefore, I would recommend a carbon fiber bike CFRP as it has a better impact on the performance of the bike.

Bibliography/References

Bicycle Riding. (2019). Bicycle Parts & Components – Watch This Bicycle Parts Diagram. [online] Available at: http://www.bicycle-riding.com/bicycle-riding/bicycle-parts/[Accessed 2 May 2019].

Bicycle Riding. (2019). Bicycle Parts & Components – Watch This Bicycle Parts Diagram. [online] Available at: http://www.bicycle-riding.com/bicycle-riding/bicycle-parts/ [Accessed 2 May 2019].

Ecf.com. (2019). Cycling facts and figures | ECF. [online] Available at: https://ecf.com/resources/cycling-facts-and-figures [Accessed 2 Jan. 2019].

Pinterest. (2019). Mountain Bike Parts Diagram. [online] Available at: https://www.pinterest.com/pin/377809856212399133/ [Accessed 2 May 2019].

Statista. (2019). U.S. bicycle industry – market size 2004-2015 | Statistic. [online] Available at: https://www.statista.com/statistics/255614/size-of-the-bicycle-market-in-the-united-states/ [Accessed 2 Jan. 2019].

Cyclingchristchurch.co.nz. (2019). About this Website – Cycling in Christchurch. [online] Available at: http://cyclingchristchurch.co.nz/about/ [Accessed 26 Feb. 2019]. En.wikipedia.org. (2019). Aluminium. [online] Available at: https://en.wikipedia.org/wiki/ Aluminium [Accessed 13 Feb. 2019].

En.wikipedia.org. (2019). Carbon fibers. [online] Available at: https://en.wikipedia.org/wiki/ Carbon_fibers [Accessed 14 Feb. 2019].En.wikipedia.org. (2019). Carbon steel. [online] Available at: https://en.wikipedia.org/wiki/ Carbon_steel [Accessed 13 Feb. 2019].

Inc, S. (2019). Tech Talk: Bike Components for Beginners – Century Cycles – Cleveland & Akron Ohio. [online] Centurycycles.com. Available at: https://www.centurycycles.com/tips/tech- talk-bike-components-for-beginners-pg1269.htm [Accessed 4 Feb. 2019].