DESIGN AND FABRICATION OF CHAINLESS BICYCLE

DESIGN AND FABRICATION OF CHAINLESS BICYCLE

CHAPTER 1 INTRODUCTION

This model resembles a unicycle, but with the addition of a front wheel, a frame, and handlebars. It has a simple design and easy to handle. Here the chain and sprocket mechanism is removed and pedal is directly attached to the rear wheel and modifying the structure and seating arrangement. The number of moving parts and overall complexity reduced. It’s simple structure ease it’s transportation.

Fig 1.1 Design of a chainless bicycle

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DESIGN AND FABRICATION OF CHAINLESS BICYCLE

CHAPTER 2 LITERATURE REVIEW David.G.Wilson,bicycle science [2] at all described and provided the updated information on rolling drag, transmission of power from rider to wheels, braking, heat management, steering and stability, power and speed, and materials. It contains many new illustrations. It provide information about bicycle frame geometry with figures Josh betchel gives an idea about chainless bicycle and this site provides an information about how it works . he provides unique concept has two forks and pedals attached directly to the rear wheel if we want to ride a unicycle about town but it is slightly impractical, a US designer has come up with a new concept that could soon see 'double unicycles' in cities around the world.

CHAPTER 3 2

DESIGN AND FABRICATION OF CHAINLESS BICYCLE

METHODOLOGY To make chainless bicycle the pedal is directly attached to the rear wheel. The mechanism used to connect pedal with rear wheel is ratchet mechanism which is used for freewheeling. To ease the transportation a telescopic structure is provided in the top tube. Rubber bushes are provided between two different size GI pipe avoid unwanted vibration.

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DESIGN AND FABRICATION OF CHAINLESS BICYCLE

CHAPTER 4 COMPONENTS

The main components of chainless bicycle are, •

Wheel

•

Pedal

•

Top tube

•

Fork

•

Seat

•

Freewheel

•

Bearing

•

Brake

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DESIGN AND FABRICATION OF CHAINLESS BICYCLE

4.1 WHEEL A wheel is a circular component that is intended to rotate on an axle bearing. Bicycle wheels are typically designed to fit into the frame and fork via dropouts, and hold bicycle tires.

Fig 4.1 Wheel 4.2 PEDAL The bicycle pedal is the part of a bicycle that the rider pushes with their foot to propel the bicycle. It provides the connection between the cyclist's foot or shoe and the crank allowing the leg to turn the bottom bracket spindle and propel the bicycle's wheels. Pedals usually consist of a spindle that threads into the end of the crank and a body, on which the foot rests or is attached, that is free to rotate on bearings with respect to the spindle. Fig 4.2 Pedal

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DESIGN AND FABRICATION OF CHAINLESS BICYCLE

4.3 TOP TUBE The top tube connects the top of the head tube to the top of the seat tube. The top tube is made of GI pipe.

Fig 4.3 Top tube

4.4 FORK A bicycle fork is the part of a bicycle that holds the front wheel. A fork typically consists of two blades which are joined at the top by a fork crown. Above the crown, a steerer tube attaches the fork to the bicycle and the handlebars allowing the user to steer the bicycle. The steerer tube of the fork interfaces with the frame via bearings called a headset mounted in the head tube.

Fig 4.4 Fork

4.5 SEAT 6

DESIGN AND FABRICATION OF CHAINLESS BICYCLE

A bicycle seat is designed to support the rider's buttocks and back, usually in a semireclined position.

Fig 4.5 Seat

4.6 FREEWHEEL A freewheel is a device in a transmission that disengages the driveshaft from the driven shaft when the driven shaft rotates faster than the driveshaft.

Fig 4.6 Freewheel

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DESIGN AND FABRICATION OF CHAINLESS BICYCLE

4.7 BEARING A bearing is a machine element that constrains relative motion to only the desired motion, and reduces friction between moving parts.

Fig 4.7 Bearing 4.8 BRAKE A bicycle brake reduces the speed of a bicycle or prevents it from moving.

Fig 4.8 Brake 8

DESIGN AND FABRICATION OF CHAINLESS BICYCLE

CHAPTER 5 SPECIFICATION

Table 5.1

WHEEL BASE

711 mm

TOP TUBE LENGTH

508 mm

HEAD ANGLE

74 degrees

STANDOVER HEIGHT

812 mm

WHEEL SIZE

660 mm

TIRE SIZE

660 x 45 mm

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DESIGN AND FABRICATION OF CHAINLESS BICYCLE

5.1 WHEEL BASE Wheelbase is the horizontal distance between the centers (or the ground contact points) of the front and rear wheels. Wheelbase is a function of rear frame length, steering axis angle, and fork offset. Wheelbase has a major influence on the longitudinal stability of a bike, along with the height of the center of mass of the combined bike and rider. Short bikes are much more suitable for performing wheelies and stoppies.

5.2 TOPTUBE LENGTH The top tube length is the horizontal distance from the top tube/head tube junction to the seat tube.

Fig 5.1 Diagrammatic representation

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DESIGN AND FABRICATION OF CHAINLESS BICYCLE

5.3 HEAD ANGLE Also known as the steering axis, this angle influences stability in combination with fork offset by controlling “wheel flop”, or the tendancy for the wheel to turn when leaned. A steep head angle is more upright and takes less effort to turn the front wheel, especially if there is too much rake.

5.4 STANDOVER HEIGHT Stand over height is the distance from the ground to the top of the top tube. In the case of a sloping, or a curved top tube, we take the measurement at the midlength of the tube.

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DESIGN AND FABRICATION OF CHAINLESS BICYCLE

CHAPTER 6 COST ANALYSIS Table 6.1

SI.NO

MATERIALS

QUANTITY

PRICE(RUPEES)

1

Free wheel

1

75

2

Bearing (62-03)

2

350

3

GI pipe (1 inch)

750 mm

65

4

GI pipe (¾ inch)

750 mm

50

5

Wheel

2

300

6

Fork

2

250

7

Welding cost

-

1000

Total cost

2090

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DESIGN AND FABRICATION OF CHAINLESS BICYCLE

CHAPTER 7 CHALLENGES FACED

CHALLENGES Difficult to control pedal’s movement while cycle moving downwards.

REMEDY Implemented freewheel mechanism

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DESIGN AND FABRICATION OF CHAINLESS BICYCLE

CHAPTER 8 ADVANTAGES AND DISADVANTAGES

8.1 ADVANTAGES •

Simple design and small size

•

Save non-renewable resources

•

Overcomes the problem of chain misalignment

•

This model offering a rear-steering option that offers the possibility of "crab-riding“

•

Economic

8.2 DISADVANTAGES •

Low speed-ratio compared to ordinary bicycle

•

Difficult to handle for a new user

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DESIGN AND FABRICATION OF CHAINLESS BICYCLE

CHAPTER 9 SCOPE OF FUTURE WORK

Speed ratio can be increased by the introduction of a special type of geared hub.

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DESIGN AND FABRICATION OF CHAINLESS BICYCLE

CHAPTER 10 RESULT

Designed and fabricated a chainless bicycle

Fig 8.1 Chainless bicycle

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DESIGN AND FABRICATION OF CHAINLESS BICYCLE

CHAPTER 11 CONCLUSION

The problem of misalignment of chain is solved. This model is economical and by offering

rear steering mechanism The

turning

Transportation of this model is easy due to the telescopic structure.

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radius gets reduced.

DESIGN AND FABRICATION OF CHAINLESS BICYCLE

REFERENCE

[1] Pacejka ,Hans.B, 2006,Tire and Vehicle Dynamics 2nd edition, Society of Automotive Engineers Inc, pp. 517–585. [2] David.g.wilson,2004,bicycle science,,3rd edition ,Mit press page no311-348 [3]http://ocw.mit.edu/courses/experimental-study-group/es-010-chemistry-of-sports-spring2013/lecture-notes/MITES_010S13_lec6.pdf [4] Josh betchel,2012, ww.kickstarter.com/projects/joshbechtel/the-bicymple [5]Introducing the bicymple: Concept bike will allow commuters to ride sideways to beat congestion http://www.dailymail.co.uk/sciencetech/article-2214494/The-double-unicycleultimate-urban-riding-machine-ride-sideways.html#ixzz46w2M64tG

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DESIGN AND FABRICATION OF CHAINLESS BICYCLE

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