Rear Derailleur Question
11-13-14 | 04:04 PM
#1
Thread Starter
Senior Member
Joined: Dec 2011
Posts: 2,921
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From: NE Ohio
Bikes: 1992 Serotta Colorado II,Co-Motion Speedster, Giant Escape Hybrid, 1977 Schwinn Super Le Tour
Rear Derailleur Question
When using a double or a triple chain ring set-up are there specific rear derailleurs?
Thanks!
Thanks!
11-13-14 | 04:09 PM
#2
Old fart
Joined: Nov 2004
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From: Appleton WI
Bikes: Several, mostly not name brands.
It depends on how much chain needs to be wrapped by the derailleur. Triples generally require a lot of chain wrap, which would call for a long-arm rear derailleur, but compact doubles can require just as much. Racing bikes with relatively close gearing don't need to wrap as much chain, and thus can use a shorter arm, and thus lighter, rear derailleur.
11-13-14 | 04:25 PM
#3
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From: Pearland, Texas
Bikes: Cannondale, Trek, Raleigh, Santana
Brad
11-13-14 | 05:32 PM
#4
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From: Roswell, GA
Bikes: '93 Trek 750, '92 Schwinn Crisscross, '93 Mongoose Alta
When you calculate the chain wrap you need you might want to consider allowing for a possible future change to a larger rear cog. A lot of folks ask about lower gearing on this forum and a larger cog is often suggested. The weight and performance penalties for a longer-than-needed derailleur arm are small if even perceptible.
