| 摘要 |
<p>The down tube for a bicycle handlebar has a gear change controlled by a lever (2). The axis of this is carried by the down tube (3) and is one piece with the down tube. The tube is a pressure casting with the axis cast in or the tube can be steel with the axis welded to it. All the lever parts are placed on the tube, then threaded on to the down tube and fixed to hold it to prevent turning. A boss gives suitable seating.</p> |
