Publication:

齒輪比及踩踏迴轉數對休閒騎士騎乘特定坡道之生物效率探討

本研究的目的旨在探討於環島最陡坡 (8%) 騎乘時，如何使用適當的齒輪比，搭配適當的踩踏迴轉數，方能達到最佳的生物效率。本研究以三位具單車環島經驗，但非受過單車專業訓練的男性學生為受試者，其年齡20.93±1.47歲，環島次數1.67±0.47次，身高171.33±1.89 cm，體重71.17±3.27 kgw，胯高長（從鞋底到恥骨的距離）79.33±0.47 cm（平均數±標準差），分別使用齒輪比1.15、1.50、2.00，搭配踩踏迴轉數45、60、78 rpm，於8%（約4.57°）坡度的跑步機上，進行八種騎乘距離為1公里的騎乘測試，並收集所有受試者的外部輸出功率值、呼吸交換率、心跳率、攝氧量、二氧化碳量，經由計算所有受試者在八種測試過後之騎乘總效率值 (gross efficiency) ，分析其最具效率的齒輪比、踩踏迴轉數之組合模式為何。另外，本研究也分析在固定騎乘速度下 (10.70m/h) ，使用高踩頻 (78 rpm) 及低踩頻 (45 rpm) 之效率變化情形為何。結果顯示出於8%坡度的跑步機，進行八種騎乘測試下，以齒輪比2.20搭配踩踏迴轉數45rpm最具效率 (21.31±1.75) ；另外在固定騎乘速度下，使用低踩頻 (45 rpm) 的總效率值 (21.31±1.75) 優於使用高踩頻 (78 rpm) 的總效率值 (17.59±1.39) 。總之，對於休閒騎士而言，於8%上坡騎乘時，使用齒輪比2.00，搭配45 rpm最具騎乘效率。

To acquire the optima gear ratio and revolution per minute in uphill riding on 8 % slope to reach the best biological efficiency, three amateur cyclists, which average age are 20.93±1.47 years with average height at 171.33±1.89 cm , weight at 71.17±3.27 kg and legs length at 79.33±0.47 cm , were recruited. The combination of three gear ratios as 1.15、1.50、2.00 and three revolution per minutes in bicycles riding on treadmill at about 4.57° slope for one kilometer were separately performed. During the experiment, the external outputting work in bicycles as well as respiratory exchange ratio, heart rates, oxygen consumption and exhaled carbon dioxide in subjects were carefully determined to calculate the gross efficiency. The data has shown that the gear ratio at 2.20 and RPM at 45rpm can reach the optima biological efficiency at 21.31±1.75. When cyclists keep at fixed speed, we obtained the greater gross efficiency (21.31±1.75) in lower RPM at 45rpm than in higher RPM at 78rpm (17.59±1.39). In summary, for amateur cyclists, riding on 8 % slope, using the gear ratio at 2.20 and RPM at 45rpm could reach the best biological efficiency.