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
International Federation for the Promotion of Mechanism and Machine Science are: International Federation for the Promotion of Mechanism and Machine Science International Federation for the Promotion of Mechanism and Machine Science (IFToMM) is an organization that supports international exchange of researchers and engineers from the wide range of discipline related to Mechanical Engineering. To promote research and development in the field of Machines and Mechanisms by theoretical and experimental methods, along with their practical application. It was on September 29, 1969m at the Second World Congress on Theory of Mechanisms and Machines which took place in Zakopane (Poland), that two scientists, Ivan Artobolevski (USSR) and Erskine Crossley (USA), proposed to