Friction Shifting
Originally, gear control levers consisted of a simple lever. Changing gears required pushing or pulling the lever so that the derailleur would move the chain to a different sprocket on the rear hub. The cyclist would need to adjust the lever to center the chain on the sprocket.
This system started out with 2 or 3 sprockets, and by the 1970s had developed to 5 and 6 sprockets. Many inexperienced cyclists, especially those who started in the US 1970s bike boom, found it difficult to change gear accurately. Typical difficulties included gear changes that left the chain in between two sprockets, which causes noisy rattles, or undesired and unexpected gear changes. However, many experienced cyclists still prefer friction gears for their simplicity and long-term reliability, as well as the ability to mix and match components from different manufacturers without the compatibility issues of indexing systems. Another benefit of friction shifting is the ability to shift from the lowest to highest gear in one simple motion. In addition, the introduction of ramped freewheel sprockets (such as Shimano's Hyperglide system) and derailleurs with floating jockey wheels has made accurate gear changes much easier than previously. Friction or ratcheting shifters remain popular for front derailleurs, since only two or three chainrings are used, and allow trimming of the front derailleur.
Read more about this topic: Shifter (bicycle Part)
Famous quotes containing the words friction and/or shifting:
“We have got onto slippery ice where there is no friction and so in a certain sense the conditions are ideal, but also, just because of that, we are unable to walk. We want to walk so we need friction. Back to the rough ground!”
—Ludwig Wittgenstein (1889–1951)
“I believe that history has shape, order, and meaning; that exceptional men, as much as economic forces, produce change; and that passé abstractions like beauty, nobility, and greatness have a shifting but continuing validity.”
—Camille Paglia (b. 1947)