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gears

Old 12-02-17, 03:14 PM
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Achinulo
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gears

Please can someone explain the concept of indexing in gear shifting.
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Old 12-02-17, 03:19 PM
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It's actually too simple.

Indexing refers to shifting via a system that clicks into each gear, vs. the older system for derailleurs where the lever had no fixed positions and the rider had to manually trip the derailleur.

Think of it in terms of climbing a slope via steps vs. a ramp.
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Old 12-02-17, 03:29 PM
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the single cable has a set of detents, notches it pulls the cable a designed distance , corresponding to the distance between the cogs

as interpreted by the rear derailleur, which turns that cable pull increment, into an inward motion ,

Placing the guide pulley directly under each cog of the rear gear cluster..

so shifter and cog spacing must be synchronized, on opposite ends of the cable..





.....
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Old 12-02-17, 11:28 PM
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Thanks guys it's clearer now.
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Old 12-02-17, 11:38 PM
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Indexed shifting is like the keys on a piano; each key produces the same given note each time that key is struck. Friction shifting is like playing the trombone, or violin; practice tells you where your fingers or hand needs to stop to produce the same given note each time.
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Old 12-02-17, 11:41 PM
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Originally Posted by JohnDThompson View Post
Indexed shifting is like the keys on a piano; each key produces the same given note each time that key is struck. Friction shifting is like playing the trombone, or violin; practice tells you where your fingers or hand needs to stop to produce the same given note each time.
John,

Great analogy. I think I'll steal it, except fine tune it a bit and use a violin and guitar.
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Old 12-03-17, 08:03 AM
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Originally Posted by JohnDThompson View Post
Indexed shifting is like the keys on a piano; each key produces the same given note each time that key is struck..
Way OT but your analogy reminds me of a rather dismissive comment about the piano:

"All you have to do is strike the right key at the right time and the thing plays itself."

The author was a rather minor composer named...... J. S. Bach
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Old 12-03-17, 10:57 AM
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Digital vs. analogue.

Index shifting is right until it's not. Friction shifting can be massaged into compliance.
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Old 12-03-17, 11:30 AM
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Originally Posted by JohnDThompson View Post
Indexed shifting is like the keys on a piano; each key produces the same given note each time that key is struck. Friction shifting is like playing the trombone, or violin; practice tells you where your fingers or hand needs to stop to produce the same given note each time.
I don't remember if it was this forum or another, but I remember someones sig line was something like, "indexed shifting is like frets on a fiddle"
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