不同加重位置及方式對網球拍物理特性改變之探討

Physical Property of the Tennis Racket after Adding Tape Different Positions

本研究主要在探討網球拍在加重後，不同加重位置所造成的球拍本身物理性質的改變，利用科學儀器來測定在不同的加重方式位置所產生的改變差異，來了解如何正確的用加重鉛片，以達到改變網球拍的擊球特性，並増進回擊球力道。本研究使用兩種不同的加重鉛片，一為市面量產制式化的鉛片，另一種為捲軸式加重鉛片，使用Babolat Racket Diagnostic Center(RDC)球拍測試儀，檢驗將兩種相同重量的加重鉛片放置在拍面5個不同位置上時，球拍的轉動慣量、平衡點以及硬度的變化。實驗所得的資料結果分析可以發現，在不同的加重方式對網球拍轉動慣量、平衡點及球拍框勁度的改變。在加相同重量鉛片於球拍上時，兩種不同的加重鉛片對於球拍的轉動慣量與平衡點的影響相似，依照加重位置的不同，其改變量大小，依序是：12點鐘＞2、10點鐘＞3、9點鐘＞4、8點鐘＞6點鐘。而在球拍的硬度上改變，兩種不同的加重鉛片則有不同的影響，制式化的鉛片並不會對於球拍硬度有所改變，而使用捲軸式加重鉛片時，若加重於3、9點的地方改變較多增加了約2個應力單位；2、10點與4、8點鐘略有增加；而6、12點鐘位置幾乎沒有改變。以上結果可作為網球運動者在考量利用鉛片加重以促進運動表現時的參考依據。

Proper use of the lead weight tape could change the physical property of the tennis racket, and hence may increase the stroke power. The aim of this study is to investigate the changes of the physical properties of the tennis racket after adding two kinds of lead weight tapes on different positions of the frame. The added lead weight is 12-g in total with 4 separate pieces of lead tapes, which were then adhered to 5 different positions on both sides of the racket frame symmetrically. The Babolat Racket Diagnostic Center (RDC) was used to examine the changes of tennis racket, including the racket swingweight, balance and stiffness. The results showed that different kinds of the lead weight materials have similar influence on inertia except the commercialized lead tape would increase more inertia than the reel lead tape especially in 12 o'clock. The increasing order of the swingweight and balance point is 12 o'clock > (10 o'clock and 2 o'clock) > (9 o'clock and 3 o'clock) > (8 o'clock and 4 o'clock) > 6 o'clock. Two different kinds of the lead weight materials have little divergent effect on changes in stiffness. The commercialized lead tape would not affect the racket stiffness while the reel lead tape increased the racket stiffness in (10 o'clock and 2 o'clock), (9 o'clock and 3 o'clock) and (8 o'clock and 4 o'clock) conditions. These results can be used as a reference when tennis players consider adding some lead weight on their rackets in order to enhance their sport performance.