• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.4
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• pp.393-400
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• 2014

In this study, an automatic transmission was developed for a bicycle. This transmission uses the pedal rpm and riding speed information for efficient riding. This transmission was installed on a bicycle using an internally geared hub. The automatic transmission was developed for a beginner to ride with proper gear changes. Indoor ride tests were performed to assess the performance of this transmission. Here, a 'beginner' is defined as a bicycle rider who can maintain a riding power of ~150W with a maximum heart rate of ~80%. Furthermore, 'ride with proper gear change' means that the rider could ride the bicycle while maintaining an efficient pedal rpm by the automatic transmission. One expert and four beginners participated in the ride test. The expert was chosen for the comparison with the beginners. To minimize environmental disturbances, the ride test was performed indoors. In this test, two types of gear changes manual and automatic were tested on two types of roads a road with a gradual incline of 0-3% and a road that simulates the bicycle road along the Han river in Seoul. The results of the ride tests show that the algorithm applied for the automatic transmission helps beginners to ride the bicycle efficiently.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.3
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• pp.269-275
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• 2009

This paper represents a study on the conceptual design of new automatic bicycle transmission. The gear change in a commercial bicycle is carried out by moving the chain between sprockets. By the use of a multiple sprocket for speed change the power loss and transmission shock may occur. To solve the problem of bicycle transmission, the improved solution was derived by the technical contradiction matrix of TRIZ. The conceptual solution is one sprocket which replaces the function of multiple sprockets and adapts actively to the pitch of chain. And it was confirmed to be an adequate design through the Independence Axiom of design axiom.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1022-1027
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• 2008

This paper represents a study on the conceptual design of new automatic bicycle transmission. The gear change in a commercial bicycle is carried out by moving the chain between sprockets. By the use of a multiple sprocket for speed change the power loss and transmission shock may occur. To solve the problem of bicycle transmission, the improved solution was derived by the technical contradiction matrix of TRIZ. The conceptual solution is one sprocket which replaces the function of multiple sprockets and adapts actively to the pitch of chain. And it was confirmed to be an adequate design through the Independence Axiom of design axiom.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.7 s.196
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• pp.75-82
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• 2007

This paper represents a study on the development of the conceptual design for the bicycle transmission by TRIZ. At first the problem of the transmission of commercial bicycles was analyzed. The problem was defined as "the variable sprocket pitch diameter with respect to the tension change of chain". The conceptual solutions were derived by Su-Field Model Analysis, IFR(Ideal Final Result), SLP(Smart Little People), and Contradiction Matrix. The here developed sprocket prototype shows the automatic change of sprocket pitch diameter with the tension change of chain.