Proposed Road Bike Brake Lever Measurements for Filipino

Proposed Road Bike Brake Lever Measurements for Filipino
China-USA Business Review, December 2015, Vol. 14, No. 12, 628-635
doi: 10.17265/1537-1514/2015.12.007
D
DAVID
PUBLISHING
Proposed Road Bike Brake Lever Measurements for Filipino
College Women in Mega Manila Area
Ranz Cosio Ramos, Angelo Concepcion Ani, Stephanie Caridad Dela Rosa Landicho,
Haerold Dean Zapata Layaoen, Micah Alviar Ramirez, Josefa Angelie Dilla Revilla
University of the Philippines Los Baňos, Laguna, Philippines

This study aims to develop sets of measurements for road bike brake lever that are suitable for Filipino college
women in Mega Manila Area. Reaching the brake levers is a common problem among women, who generally have
shorter hands. This study wishes to address this issue. Correspondences between anthropometric measurements and
brake lever measurements were first established. Relevant hand anthropometric data, together with height, were
collected from female students in three colleges in the Philippines to establish the said bike part measurements.
Several statistical analyses were conducted. ANOVA was used to check the effect of school and height to hand
length. Correlation coefficients were computed to determine the relationship of height to some hand anthropometric
measures. Three sets of measurements—small, medium, and large—were computed based on the hand
anthropometry. Another group of students tested a prototype of the proposal alongside an existing brand of brake
lever. The validation suggested that more students preferred the prototype over the branded bike part, providing a
case for the proposed measurements.
Keywords: anthropometric data, Filipina, hand anthropometry, road bikes, brake levers
Introduction
Road bike, compared to other bicycle types, is characterized by having more gear combinations, being
lighter, and having skinnier tires and drop handlebars. It is suitable to be ridden on smooth pavement. Its brake
levers and gears shifters, which control the brakes and gearing of the bike, respectively, are mounted on the
handlebar. As brake levers and gears shifters are usually integrated, this study simply calls the set as brake lever
for brevity.
A usual problem encountered by women cyclists with shorter hands is reaching for the brake lever
Ranz Cosio Ramos, industrial engineer, Department of Industrial Engineering, University of the Philippines Los Baňos, Laguna,
Philippines.
Angelo Concepcion Ani, assistant professor, Department of Industrial Engineering, University of the Philippines Los Baňos,
Laguna, Philippines.
Stephanie Caridad Dela Rosa Landicho, instructor, Department of Industrial Engineering, University of the Philippines Los
Baňos, Laguna, Philippines.
Haerold Dean Zapata Layaoen, assistant professor, Department of Industrial Engineering, University of the Philippines Los
Baňos, Laguna, Philippines.
Micah Alviar Ramirez, instructor, Department of Industrial Engineering, University of the Philippines Los Baňos, Laguna, Philippines.
Josefa Angelie Dilla Revilla, assistant professor, Department of Industrial Engineering, University of the Philippines Los Baňos,
Laguna, Philippines.
Correspondence concerning this article should be addressed to Josefa Angelie Dilla Revilla, Department of Industrial
Engineering, University of the Philippines Los Baňos, Laguna 4031, Philippines.
MEASUREMENTS FOR FILIPINO COLLEGE WOMEN IN MEGA MANILA AREA
629
(McCracken, 2015). While there are adjustment mechanisms, such as adding fillers to the brake levers to
improve the fit, the necessary adjustments imply that current brake lever standards are biased against women.
Statistics from Del Prado-Lu (2007), Census at School Canada (n.d.), and Pheasant (1998) consistently
provide evidence that hand lengths of females are generally shorter than the male counterparts.
In order to address the differences among bike users, cyclists resort to bike sizing and bike fitting. Bike
sizing takes into consideration one’s height and inseam length to identify an appropriate frame size and other
bike parameters using rules of thumb. However, no known bike sizing guide is available for brake lever
measurements. Bike fitting, meanwhile, is a more sophisticated professional service that really personalizes
bike part dimensions by considering more body measurements and even movements. The cost of the service,
however, limits its widespread use.
The main objective of this study is to develop sets of measurements related to brake levers that are
appropriate for Filipina college students with ages 17 to 21. The study focuses on college students as Baltes
(1996) implied that college students have a higher tendency of using bicycles relative to the general population.
Research Background
There are a number of studies that tackle the ergonomic aspects of bicycles. In 2010, Laios and Giannatsis
proposed new measurements for five critical children bicycle dimensions. The study produced three sets of
measurements corresponding to three sizes appropriate for Greek children aged seven to 14 based on an
anthropometric database. A relatively similar study for young Dutch children was published earlier (Donkers,
Toussaint, Molenbroek, & Steenbekkers, 1993). Just recently, Manas and Ingole (2015) proposed an adjustable
handlebar design based on the anthropometric data of 100 males. None of these studies, however, tackle brake
levers. These articles also emphasized that anthropometric data are very important input in evaluating bike part
measurements.
In the Philippines, there are limited sources of anthropometric data accessible for research purposes. Two
of these are from Zubia et al. (2010) and Del Prado-Lu (2007). The former covered the anthropometry of male
farmers in Laguna, Philippines, while the latter studied Filipino manufacturing workers. The problem, however,
for these two sets of anthropometric data is that they have limited information on different hand measurements
that are relevant for bike brake dimensions. This requires the researchers to gather the necessary set of
anthropometric data.
A study that emphasized that bicycles are usually designed based on male anatomy, even though there are
significant anatomical differences between the two sexes (Ingole, Awate, & Manas, 2015). The same study,
therefore, proposed some changes to the bicycle that would make it more favorable to women. While the said
study provided recommendations for a number of bike parts, such as distance between saddle and handlebar,
saddle height and shape, and handlebar rod diameter, it was noted that brake levers were not considered.
Research Organization
The study aimed to propose measurements related to the brake lever appropriate for the target
demographics as mentioned earlier. Furthermore, the proposed measurements aimed to improve fit—how users
reach the brake lever while cycling—rather than aesthetics. While more sophisticated design of brake levers
and gear shifters are available, this study considered only the measurements of a simple design where the brake
levers act as gear shifters as well when moved sideways.
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MEASUREMENTS FOR FILIPINO COLLEGE WOMEN IN MEGA MANILA AREA
Estimation of Relevant Brake Lever Measurements
Based on cycling experience, there are three common hand positions related to the use of brake levers as a
cyclist uses a road bike. Each of these positions corresponds to a relevant measurement as summarized in Table
1. It also presents the approximate anthropometric measurements corresponding to the said dimension. As these
are just approximations, other study may provide different estimates.
Table 1
Relevant Measurements and Corresponding Approximate Anthropometric Measurements
Measurement
Handlebar to brake lever
Importance
Anthropometric measurements*
≈O+C+B
In the aggressive position, the palm leans
where,
on the drop bar while maintaining steady
O (upper palm);
reach of the brake lever.
C (index finger proximal phalanx);
B (index finger middle phalanx).
Bracket to brake lever (top)
≈ 0.5D + O + 0.5E
In the relaxed position, the palm leans on
where,
the bracket while maintaining contact to
D (lower palm);
the upper part of the brake lever.
O (upper palm);
E (middle finger proximal phalanx).
Bracket to brake lever (bottom)
≈ 0.5D + O + E + F
In the relaxed position, the cyclist brakes
where,
by pulling the lower portion of the brake
D (lower palm);
lever as the palm leans on the bracket.
O (upper palm);
E (middle finger proximal phalanx);
F (middle finger middle phalanx).
Note. * It refers to Appendix A for the illustration of hand parts.
Collection and Analyses of Anthropometric Data
As explained earlier, anthropometric data are important inputs to establish the relevant brake lever
measurements. Female students from three schools from the Mega Manila Area were randomly selected to
participate in the study. These are major universities with large and ethnically-diversed population. Height,
measurement of the phalanges of the index and middle fingers, and lengths of upper and lower palms were
measured using appropriate tools, such as anthropometer and calipers.
A statistical software was employed to perform some statistical analyses to the anthropometric data
collected. These tests included normality tests and paired t-test to check the difference between right and left
hand measurements and ANOVA to determine the effect of school and age to hand length. Correlation
coefficients are likewise computed to measure the linear relationship between height and several hand
measurements.
Computation of Bike Part Dimensions
Three sets of measurements were developed corresponding to small, medium, and large. The proposed
measurements for the road bike brake levers were based on the 25th, 50th, and 75th percentile of the relevant
MEASUREMENTS FOR FILIPINO COLLEGE WOMEN IN MEGA MANILA AREA
631
measurements. This is consistent with what is used in most of the commercial digital human modeling tools,
which uses five groups: very small (fifth percentile), small (25th percentile), medium (50th percentile), large
(75th percentile), and very large (95th percentile) (Mun & Rim, 2011).
Validation of Measurements
A prototype corresponding to the medium size was constructed. It was installed on handlebar mounted
on a stationary bike. Another setup that features an existing model of brake lever was likewise made
available. A group of students tested these two setups. Both the relaxed and aggressive positions were asked to
be performed by the students. After that, they were asked to choose which between the two setups fits them
better.
Results and Discussion
Number of Samples
Table 2 summarizes the number of students who took part in the study broken down into school and age
groups. A total of 122 students took part of the study.
Table 2
Total Number of Respondents Grouped According to School and Age
School
Number of respondents per age group
Total
17
18
19
20
21
School A (NCR)
13
11
12
5
5
46
School B (Region 4A)
6
10
12
6
5
39
School C (Region 4A)
5
10
12
5
5
37
Total
24
31
34
16
15
122
Summary of Anthropometric Measurements
Table 3 presents key descriptive statistics of some important anthropometric measurements. For hand
dimensions, only the right hand measurements are shown as little deviation exists between the corresponding
left and right hand measurements.
Table 3
Descriptive Statistics of Anthropometric Measurements (in cm)
Percentile
Measurements
Mean
Std. Dev.
Min.
Max.
5th
50th
95th
Height
158.11
5.04
146
168
150.11
158.60
166.95
Index finger proximal phalanx
2.21
0.26
1.3
3.0
1.90
2.20
2.70
Index finger middle phalanx
2.13
0.26
1.1
3.0
1.71
2.10
2.50
Index finger distal phalanx
2.27
0.19
1.8
2.7
2.00
2.30
2.60
Middle finger proximal phalanx
2.50
0.32
1.8
3.3
2.00
2.50
3.00
Middle finger middle phalanx
2.43
0.28
1.8
3.2
2.00
2.50
2.90
Middle finger distal phalanx
2.40
0.24
1.7
3.1
2.10
2.40
2.80
Upper palm
3.68
0.50
2.5
5.0
2.80
3.70
4.50
Lower palm
4.98
0.59
3.6
6.7
4.20
4.95
6.10
MEASUREMENTS FOR FILIPINO COLLEGE WOMEN IN MEGA MANILA AREA
632
Statistical Tests
Here are some of the results of the statistical tests made on the anthropometric measurements:
(1) Using Chi-square to test goodness of fit, there is no evidence to conclude that the observations do not
come from a normal population;
(2) Paired t-tests conducted revealed that the average differences between corresponding left and right
hand measurements are zero;
(3) Using a general linear model, analysis of variance suggested that school and age do not affect hand
length, which is the total length of palm and middle finger (the result is presented in Table 4);
(4) Hand measurements only have weak to moderate linear correlation with height. The correlation
coefficients are summarized in Table 5. This implies that an approach that approximates brake lever
measurements using height of the cyclist has limited accuracy.
Table 4
Analysis of Variance for Right Hand Length Versus School and Age
Source
d.f.
Seq. SS.
Adj. SS.
Adj. MS.
F Stat.
P-value
School
Age
Error
2
4
115
3.446
1.306
136.764
3.405
1.306
136.764
1.703
0.327
1.189
1.43
0.27
0.243
0.894
Total
121
141.516
Table 5
Pearson Correlation Between Height and Right Hand Measurements
Hand measurements
Correlation with height
Right index finger
Right middle finger
Right palm
0.299
0.363
0.310
Right hand length
0.373
Comparison With Existing Anthropometric Measurements
A number of sources provide statistics for the hand length as shown in Table 6 below.
Table 6
Hand Lengths of Different Populations
Percentile, in cm
Reference
Population
5th
50th
95th
Zubia et al. (2010)
Filipino male farmers in Laguna
16.0
17.5
19.0
Filipina manufacturing workers
15.5
18.0
20.0
Filipino manufacturing workers
17.0
19.75*
21.5
American female NASA personnel
15.8
17.2
18.7
American male NASA personnel
17.9
19.3
20.6
British female adults
15.9
17.4
18.9
British male adults
17.3
18.9
20.5
Female college students
14.4
16.0
17.9
Del Prado-Lu (2007)
National Aeronautics and
Space Administration
(1995)
Pheasant (1998)
This study
Note. * Estimated using the mean as the data point is not available.
MEASUREMENTS FOR FILIPINO COLLEGE WOMEN IN MEGA MANILA AREA
633
Based on Table 6, the median hand length of male Americans is about 20% longer than the median
measured in this study, while median hand length of British male adults is 18% longer. If existing brake lever
standards are based on Western male adult, it is safe to say that these may not perfectly fit a Filipina college
student. Female American and female British median hand lengths are longer than that of the Filipina college
students by 7.5% and 8.8%. The study produced the shortest set of hand length measurements among the
references cited above.
It is also noteworthy to mention that the results of Del Prado-Lu (2007) produced the largest set of hand
lengths, higher than corresponding foreign counterparts. This is in conflict with the result of Zubia et al. (2010)
which suggests that Filipino hand lengths are generally shorter than hand lengths of American and British
males.
Recommended Brake Lever Measurements
The collected anthropometric data enabled the study proponents to propose appropriate measurements for
the target population as shown in Table 7 below. These are based on the formula discussed in Table 1, noting
that 25th, 50th, and 75th percentiles correspond to small, medium, and large sizes, respectively.
Table 7
Proposed Brake Lever Measurements
Measurement
Handlebar to brake lever
Bracket to brake lever (top)
Bracket to brake lever (bottom)
Small
7.60
7.05
10.50
Proposed measurement (in cm)
Medium
Large
8.00
8.40
7.35
7.78
10.98
11.69
Actual brake level dimensions were computed using the said proposed measurements. Figure 1 illustrates
the final proposal. It notes that since not all dimensions are related to the parameters in Table 7. Segment D, for
example, is not related to segments H, I, and J.
Figure 1. Proposed dimensions of brake levers.
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MEASUREMENTS FOR FILIPINO COLLEGE WOMEN IN MEGA MANILA AREA
Result of Prototype Validation
Another group of 80 female students, aged 17 to 21, in “school C” were asked to evaluate two brake lever
setups: (a) prototype of the proposed medium-sized brake lever and (b) a branded break lever. The students,
who tried the setups in stationary bike, were asked to identify which between the setups fits them better. Table
8 summarizes the responses.
Clearly, based on the results, the proposed measurements helped improve the fit of the brake lever setup to
the target demographics as indicated by respondents’ preference. The prototype outperforms the existing brake
lever setup particularly in the relaxed position configuration.
Table 8
Preferred Brake Lever Setup of Respondents
Relaxed position
Aggressive position
Overall
Prototype
Existing
Prototype
Existing
Prototype
Existing
72%
28%
51%
49%
67%
33%
Conclusions
There are no established standards for Filipinos regarding the size of road bicycle and its parts. The current
sizes of road bike parts and accessories are intended for Western standards and they may not be considered “fit”
for Filipinos.
This study aimed to provide new sets of measurements for road bike brake levers that cater to the hand
sizes of Filipino college women in Mega Manila Area aged 17 to 21. The researchers were able to achieve this
objective by gathering the required anthropometric data of college students from three different schools in NCR
and Region 4A. Three sets of measurements were developed—small, medium, and large.
To validate the new measurements, a prototype of the medium-sized brake lever and shifter was fabricated.
Results of the validation highlighted the preference of respondents for the prototype as opposed to the existing
set of brake levers.
References
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Statistical Area Data. Transportation Research Record, 1538, 96-105.
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Del Prado-Lu, J. (2007). Anthropometric measurement of Filipino manufacturing workers. International Journal of Industrial
Ergonomics, 37(6), 497-503.
Donkers, P. C. M., Toussaint, H. M., Molenbroek, J. F., & Steenbekkers, L. P. (1993). Recommendations for the assessment and
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MEASUREMENTS FOR FILIPINO COLLEGE WOMEN IN MEGA MANILA AREA
635
Mun, J. H., & Rim, Y. H. (2011). Human bony modelling. In L. Canetta, C. Radaelli, and M. Flore (Eds.), Digital factory for
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Appendix A: Hand parts
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