# Top vs. Bottom Swing front derailleur



## bloodyknee (Jul 29, 2008)

Was wondering if someone could give me a quick lesson on the advantage/disadvantage of a top swing vs. bottom swing front derailler?


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## flipnidaho (Aug 10, 2004)

your choice should depend on the type of frame you have. Some frames require a traditional (bottom swing) FD to clear any type of gusseting (or even water bottle cage bolts) on the seat tube/down tube junction. Some frames require a top swing to clear linkages in some suspension designs (or if the frame is an interrupted seat tube and there is only a little stub of a seat tube coming ouf of the bb).


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## wmodavis (Jun 21, 2007)

+1 to flipnidaho. I had to use a bottom swing because of that very reason. Fortunately the LBS allowed me to exchange the one I bought before knowing it wouldn't fit my specific frame.


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## bloodyknee (Jul 29, 2008)

+2 to flpnidaho for answering a dumb question without making me feel stupid.


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## flipnidaho (Aug 10, 2004)

Here is an example from my bike of a frame that needed a bottom swing because of an interrupted seat tube... A bottom swing would not have worked because of the lower linkage and the way the seat tube is brazed on to the upper linkage support.


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## forkboy (Apr 20, 2004)

bloodyknee said:


> +2 to flpnidaho for answering a dumb question without making me feel stupid.


I wouldn't call it a dumb question. There are what - 6 different methods? TPTS TPBS BPBS BPTS DPTS DPBS.... Not to mention all the iterations - E-type, braze on, 3 different tube sizes..

And some frames can use multiple types.

Yeah - I've got a box of front derailleures that don't fit anything I own, but as soon as I sell one, I end up needing it a few months later.


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## mtnbiker72 (Jan 22, 2007)

*Exactly*



forkboy said:


> I wouldn't call it a dumb question. There are what - 6 different methods? TPTS TPBS BPBS BPTS DPTS DPBS.... Not to mention all the iterations - E-type, braze on, 3 different tube sizes..
> 
> And some frames can use multiple types.
> 
> Yeah - I've got a box of front derailleures that don't fit anything I own, but as soon as I sell one, I end up needing it a few months later.


I can't tell you how many times I've done that...doubt!


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## KINBOY (May 23, 2004)

I have an old Campy that is reverse pull, when pulled it swings inwards!!! It was off a scrap bike ages ago and threw me for a loop.
KIN


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## grawbass (Aug 23, 2004)

KINBOY said:


> I have an old Campy that is reverse pull, when pulled it swings inwards!!! It was off a scrap bike ages ago and threw me for a loop.
> KIN


Some old Suntours work that way too.


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