| The gears worked smoothly, to the minor accompaniment of the ratchet clicking and the links passing over the drive sprocket. |
| Then, in some unexplained way, the sprocket chain tore loose and managed to wrap itself about the boy's neck, strangling him. |
| The small sprocket wheel in turn is coupled to the ratchet wheel, which allows only the uni-directional rotation of the ratchet sleeve shaft. |
| The derailleur is the device that changes gears by moving the chain from one sprocket to another. |
| After disentangling it from around his front sprocket he fought back over the day's remaining test to claim victory. |
| Each side of the suspension system comprises six roadwheels with a front drive sprocket and a rear idler but no track return roller. |
