Low car diet
Join Date: Aug 2007
Location: Corvallis, OR, USA
Bikes: 2006 Windsor Dover w/105, 2007 GT Avalanche w/XT, 1995 Trek 820 setup for touring, 201? Yeah single-speed folder, 199? Huffy tandem.
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Most front derailleurs have three specifications:
1) Clamp diameter: 28.6, 31.8, or 34.9mm (unless it's an E-type that attaches to the bottom bracket)
2) Pull direction: top-pull (cable comes from the top of the frame usually along the top tube) vs bottom-pull (cable comes from the bottom usually under the bottom bracket)
3) Swing direction: Top-swing (the M770) vs bottom-swing (the M773)
Most newer Shimano FDs are multi-clamp (34.9mm with shims for smaller seat tubes) and multi-pull (cable can be routed from the top or bottom).
To some extent, the swing direction is more style than function. However, if the frame was designed for a particular type, then there may be interference with the frame when switching styles.
Traditionally, top-swing went with top-pull and bottom-swing went with bottom-pull. [edit: had this backwards]
Do you know what the frame's original FD's swing-direction was?