In a speed-change operation mechanism, a main body of a lock member is disposed to produce a clearance between the main body and the surface of the handle arm, whereas a pivot operation part of the lock member is disposed to close a clearance between the main body and the surface of the handle arm and simultaneously to produce a clearance between the pivot operation part and the surface of the handle arm. A relatively large clearance is produced between the main body of the lock member and the surface of the handle arm, whereas a small clearance, just enough to allow a pivot operation of the lock member, is produced between the pivot operation part of the lock member and the surface of the handle arm.本發明之課題係在於針對雙軸承捲線器的變速操作機構，可圓滑地操作鎖定板及操作旋鈕。用以解決課題之手段為，在變速操作機構(7)，鎖定構件(30)的本體部(30a)係配置成與操作桿臂(4a)的表面之間產生間隙，鎖定構件(30)的擺動操作部(30b)係設置成封住本體部(30a)與操作桿臂(4a)的表面之間的間隙、且在與操作桿臂(4a)的表面之間產生間隙。在此，在鎖定構件(30)的本體部(30a)與操作桿臂(4a)的表面之間，產生大的間隙，在鎖定構件(30)的擺動操作部(30b)與操作桿臂(4a)的表面之間，產生可進行擺動操作程度之小的間隙。
