Derailleur gears chain slack. Cage length determines the total capacity of the derailleur, that is the size difference between the largest and smallest chainrings, and the size difference between the largest and smallest sprockets on the cogset added together. A larger sum requires a longer cage length. Typical cross country mountain bikes with three front chainrings will use a long cage rear derailleur. A road bike with only two front chainrings and close ratio sprockets can operate with either a short or long cage derailleur, but will work better with a short cage. Manufacturer stated derailleur capacities are as follows: Shimano long
Dwell mechanism backwards. The cams in this application are usually phased 90 degrees apart allowing a pause in the up/down movement of the dog while it is being moved forwards/backwards. A separate adjustable sliding block or link is used to control the amount of forwards/backwards movement of the dog. Industrial applications include loading or unloading parts, or transporting a part to a machine and holding it in place for a manufacturing process. Other applications include assembly lines, package machinery, machine tools etc. Dwell mechanism A dwell mechanism (either a linkage or cam-follower type) is an intermittent motion mechanism that alternates forward and