Join Date: Feb 2004
Location: St Peters, Missouri
Bikes: Rans Rockst (Retro rocket) Rans Enduro Sport (Retro racket) Catrike 559, Merin Bear Valley (beater bike).
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Didn't answer this yeaterday?
Originally Posted by tlippy
Can anyone tell me the exact difference between a 105 double and triple FD.
I took the time yesterday to walk down to my basement where I have two Ultegra equipped bikes. One has a double front derailleur and one has a triple. At a glance I could see two obvious differences:
The triple derailleur has a much deeper blade on the inner derailleur cage. I assume this is to assist picking the chain up off of the granny ring. The triple cage also droops down farther behind the chainrings. I assume this is to prevent rubbing on the bottom of the derailleur cage if you happen to shift into a little/little gear combination.
I'm doubtful the throw is any different since they both use the same shifter so the cable pull is identical. I'm also doubtful about cage width since they both use the same chain and a too wide cage isn't going to shift well. The pricing thing is also a little goofy. I have a catalogue that shows a 105 triple derailleur costing more than a 105 double, but the Ultegra triple derailleur costs less than the Ultegra double.