Ergonomic Design of Bicycle Handle

Transcription

1 Ergonomic Design of Bicycle Handle Mukund Manas 1, Pradeep M. Ingole 2 1 M.E., Production and Management Engg. PRMITR, Badnera, India 2 M.E., Guide, Associate Prof., PRMITR, Badnera, India Abstract The work, stress on comfort and analysis of bicycle handle. It has aesthetic measure of riding quality of the bicycle handle with respect to the anthropometric data of an Individual. An adjustable handle bar is being proposed to meet the specific individual anthropometric data. The handle bar proposes more adaptability, vibration absorption too. Based on the guidelines given by the Human Factors and Ergonomic Society (HFES) redesigning of bicycle handle is done and a unique formal bicycle handle size selection has been proposed. The design takes care of the fatigue or pain on the arm, wrist and the neck. This makes the cycling more comfortable. This is how formal bicycle handle size is being proposed. The vertical and the horizontal adjustability are taken into account so as to have proper accommodation irrespective of the various anthropometric dimensions. Keywords Pelvis, Human Anthropometry data, Ergonomics Saddle. I. INTRODUCTION The cycling position can be broadly classified as:- 1. Classic (Dutch) city bike position 2. Trekking position 3. City type 4. Sporty position The postures are shown in fig.1.1 which clearly depicts the various postures of human body while cycling. Figure1.1 The bicycle handle design revolves around three aspects to improve comfort:- 1. Ability to resist or absorb bicycle vibration. 2. Adjustability of position according to anthropometric dimensions of the cyclist. 3. Handle assessment with respect to saddle, paddle and personal anthropometric data. With wide variety of bicycle designs done to reduce weight, improve stiffness and efficiency, turning our attention to the ergonomic design to increase the cyclist comfort. Each is designed to meet specific needs posed by the intended use of the person. The wheel size, Frame, Saddle, paddle are left un-discussed. There are series of bicycle with different frames and standard sizes to meet the required fit. The saddle adjustment and the paddle adjustment with respect to the anthropometric size are effectively done. The real constrain is felt in the handle bar position and its shape in context to different anthropometric sizes. The improper handle selection causes neck pain, arm and pelvis pain while cycling. Thus different handle bar is being proposed by different manufacturers to have comfort cycling. Every now and then we have fancy handle bar in the market one after the other. But it is soon lost due to its uncomfortable design. Thus only thing we are concentrating on is the ergonomic handle bar design of bicycle. There are series of bicycle handle present and are up coming to replace the existing one. So proposing a unique bicycle handles to increase the comfort of the rider and is adjustable to large variation of human anthropometry. However, the optimum gesture on the cycle still remains a challenge. Still the design on the handle bar is evolving with time and various types always find a way in the market. So, new ergonomically developed Handle bar, stated under are framed on this background. First attempt has been made to study the correct posture while riding a bicycle. II. RESEARCH METHODOLOGY Keeping the above points in mind, the design procedure done through following steps:- The specification provided by the manufacturer Careful listening to what the body says. Don t alter too many things at once i.e. go one by one. Don t alter too many things at once. Pedal right ( smooth and in rhythm) Handle adjustment to have better fittings. 477

2 Identification Of Constrains While riding cycle, the important stress concentration on the body is shown in the figure1.2.the backbone, arms, wrist neck and forearm are subjected to maximum stress. While designing the cycle handle, this all factors directly comes into play. Figure:-1.2 shows the overall major stress concentration while cycling. Figure:-1.4 shows the stress concentration due to holding or gripping of the handle. Thus it explicitly defines the need of good anthropometric handle design to have a comfortable ride. Figure 1.5 Figure The knee should not touch the handle while the paddle is at the upper top position. Also while taking a turn the handle should not interfere with persons legs. It should be around 65deg. at the top paddle position (angle between thee and leg). The bottom position should be at This is shown in Figure :- 1.6 Suggested Remedy The following constrain are dealt with the following precaution: 1. Controlling the geometry and dimensions of bicycle handle with respect to the respective anthropometry data of an individual. Calculating the mean posture. Determining the permissible adjustment range of handle with the saddle and the paddle. Also obtaining the vertical height and calculating the minimum horizontal width. Minimum distance between the saddle and the handle should be maintained for respective human dimensions. 2. The pelvis should be correctly angled to have S shape. It is shown in Figure:-1.4 Figure : Stretching, reaching and flexing are unwanted. However posture change or various positions accommodation are always a welcome move. It gives constrain less ride. It is shown in Fig The arm should be slightly outward to deg. To counteract vibration effect on arms and shoulders as shown in figure 1.8 Figure The head chest and abdomen of person should be in line at 10 0 with the vertical. However the inclined to the vertical axis is also permissible. The inclination also helps to put extra component of weight to the paddle hence promotes forceful paddling. However it stresses on the body comfort which is shown in the Figure : Figure: Handle bar should be wider than shoulder width for comfort. The wrist position should be straight so as to have strain free ride. This is shown in figure:-1.9. The correct wrist posture makes the blood circulation effective and induces less fatigue. 478

3 d = Figure:-1.9 Under the following stated guidelines following steps has been taken:- 1. Identify major constrains, problem and task. 2. Collection of anthropometric data of people. 3. Make solution according to the problems. 4. Analysis and conformation of the solution 5. Study the attributes. Based on these grounds, redesigning new handle bar. III. DESIGN OF BICYCLE HANDLE Based on above guiding specification of anthropometric posture, redefining the dimensions of handle stated below step by step. A. Handle Adjustability Respect To Saddle These are verified by the properties of triangle Where, H v = Vertical distance of handle from the saddle. D H = Horizontal distance of handle from the saddle. Ө = the angle of distance d with the horizontal. d = Distance of handle grip from the saddle. It is noted that the value of d can easily be converted to the value of H v and D H. Thus, calculating d to describe its component into horizontal and vertical distances. The value of hundred people data has been taken. The collected data has been processed and shown the Table: The average value and the limiting case have been shown in the graph itself to describe the handle position with respect to Saddle. The mean total arm length of people comes to be 596 mm considering that man holds the handle with straight arm, the limiting case as shown in figure 1.15(c). This is the extreme case of handling. Below this limit person can readily accommodate. Above this, comfort greatly reduces. The stomach abduct mean value is 592mm. The mean angle between chest and arm is From this value the mean d is coming to be 775mm. Table: Figure: First and foremost, deciding the position of handle with respect to the Saddle. For any human anthropometric data given, the distance of the handle i.e. (horizontal and vertical distance is given by SinӨ CosӨ Once handle position is calculated with respect to saddle, concentrating on the handle bar shape. So proposing the handle of C -Frame with the vertical and the horizontal adjustment as shown in the figure:- 1.11(a) and figure:-1.12(b). The handle proposes various adjustable postures and grips with personal, adjustable anthropometric comfort dimensions. 479

4 Figure 1.11(a) Figure 1.11(b) The C shaped handle bars have lateral and transverse accommodations to strive for the different range of anthropometric data of a man. The first handle proposes more adjustability with better wrist grip due to the adjustability of the handle in three ways. But the present popular handle bar proposes only two adaptations. However in both the case we can have the vertical and horizontal adjustments with different physical data. The angular twist in the C frame handle of figure1.11 (a) is more favorable but demands more robust assembly of the joint which is achievable. It readily takes care of the stress produced due to its high accommodations of human anatomy. Now analysis of the width and vertical adjustment with grip diameter is done. This posture is the desired position of rider what so ever be his anthropometric data. The angle between the arm and the forearm of an individual is state should always less than Type B (figure:-1.13(c)) is not desirable as people feel. Person is constrained while riding as body is stretching for the grip to and get restrained. So it has been taken it as a critical posture for the distance between the handle and the saddle. The above derivation for minimum distance of saddle to handle ( d ) is based on this position. This is the minimum position required for proper body assessment on the cycle while riding. Set of hundred male anthropometric data is collected. The mean value of the handle width is 371mm as shown in table: The allowable adjustment provided is 30mm respectively on both sides i.e. inwards and outwards as shown in the Figure:-1.14(b) and Table 1.12(b) Table:-1.12 B. Width Adjustment According to Human Factors and Ergonomic Society specification the horizontal adjustment of the cycle handle should nearly equal to the shoulder width of the person. The figure:- 1.11(a) shows the front view of the cyclist and figure:- 1.12(b) and figure:-1.15(c) shows the top view position of the cyclist. C. Height Adjustment Figure:-1.11(a) Figure:-1.12(b) Figure:-1.13(c) Clearly two types of arm position from top view is shown for gripping the handle bars: - 1. Type A 2. Type B In Type A (figure:-1.12(b)) the position of the arm is inclined. This makes ride more comfort friendly due to less confinement. It s another biggest advantage is that it helps in vibration absorption. The inclined arm absorbs vibration as it resists vibration to pass from handle to shoulder thus limits shoulder pain. This position is achieved only when the rider is in proper fit with the handle and the saddle. Figure: (a) Figure:-1.14(b) There are two types of vertical adjustment possible in handle bar:- 1. Linear height adjustment. 2. Angular height adjustment. In linear height adjustment the handle bar is accommodated as shown in the figure 1.14(a). This increases the reach and decreases the bend angle of the rider pelvis in the range as shown in figure

5 The adjustable locking arrangement has been installed which can be increased or decreased, then locked to have desired fixed handle position. Two concentric hollow tubes with locking arrangement are shown in the diagram. It is more convenient method than the angular height adjustment handle bar In angular height adjustment can also account for the above accommodation, but it has limited adaptability as compared to the above arrangement. It produces circular adjustment around a radial distance. So its lateral adjustability is more as compared to the former handle. D. Grip Diameter The diameter is calculated by the equipment shown in the fig. 1.15(a). The average diameter of the handle bar is 30mm. The table: shows the desired handle grip position by set of hundred peoples. Table: IV. CONCLUSION Proposal of new adjustable handle bar whose specification are:- Material: - Carbon fibre, Steel. Tube cover for vibration reduction: - Rubber Butyl Grip Diameter: - 30mm Length of the Handle: - 370mm ± 30mm Distance of handle with saddle: - 775mm Shape of handle bar: - C-Frame as shown in fig.1.11 Tools are used for measurement:- 1. Angle measurement device (Fig. 1.15(a)) 2. Handle prototype. (Fig. 1.15(b)) Figure:- 1.15(a) REFERANCES Figure:- 1.15(b) [1] Lambros laios, John Giannatsis, Ergonomic Evaluation and redesign of children of children bicycle based on anthropometric data, Applied Ergonomics 2009 [2] S.C. Jirapure, M.W.Andure, S.W. Mohod, Ergonomic Design of a bicycle A bike of rural people [3] Joachim Vanwalleghem, Fredrik Mortier, Ives De Baere, Mia Loccuier, Wim Van Paepegem, Design of an instrumented bicycle for evaluation of bicycle dynamics andits relation with the cyclist comfort. [4] Jason K Moore, Mont hubbard, A.L. Sehwab, J.D.G. Kooijman, Dale L. Peterson, Statics of bicycle rider motion. [5] K Mallikarjun, Sumer Singh, Manas Ranjan Mishra. Design of bicycle for Indian children Focusing on Aesthetic and Ergonomics. [6] P.C.M Donkers, H.M. Toussaint, J.F.M Molenbroek, and L.P.A Steenbekkers, Recommendations for the assessment and design of young children s bicycles on the basis of anthropometric data. 481