MTB FD's - Top swing vs. Down swing?

[worriesnot]

What is the main differences between these front derailleurs and when to use which?

Current bike has a top swing on it - will a bottom swing FD work?

 

 

[droo]

Sometimes you're limited by frame design, otherwise it doesn't matter.

[tombeej]

You need to know 2 things: 

1. Where does your gear cable run down the frame (down the seat tube or the bottom tube)?

    --  This determines whether you need a top pull or bottom pull DR.

 

2. What is the position of your bottle cage on the seat tube (if you've got one there).

    --  Determines whether you need a low clamp derailleur or not.

 

Yes, the conventional FD derailleur can be a top pull and a bottom pull (dual pull). But it's got a high clamp.

 

So if you currently have a top-pull low-clamp (top swing) derailleur with cable running down the seat tube, you can install a conventional dual pull derailleur but then you're going to have 2 issues:

1. The gear cable will look ugly as it angles out away from the seat tube (doesn't run nice and snug down the tube).

2. The clamp will be too high and impact with your bottle cage on the seat tube (if you've got one there, e.g. hardtail). You'll have to remove that bottle cage completely if you insist on installing a high clamp in that situation. If you have a DS with pivots getting in the way, then you will have no choice - you'll have to use a low clamp (top swing).

[tombeej]

I realise my post might cause more confusion. A summary of my long-winded explanation:

 

Top swing = low clamp.

Bottom swing = high clamp.

 

Why not send a photo of your bike so we can see what the situation is?

[tombeej]

.

[worriesnot]

I thought it had something to do with geometry... bike is an Anthem and looks like top or bottom swing will work. 

Cable pull is form the top but most high end FD can accommodate either.

From Tombeej post I think issue no.1 is the only one to worry about as there is not bottle cage on the seat tube.

Just curious why there are two configs is all.

[tombeej]

I thought it had something to do with geometry... bike is an Anthem and looks like top or bottom swing will work. 

Cable pull is form the top but most high end FD can accommodate either.

From Tombeej post I think issue no.1 is the only one to worry about as there is not bottle cage on the seat tube.

Just curious why there are two configs is all.

 

The frame conflict is either the bottle cage (e.g. on a HT) or the pivot points on a FS.

 

I've tried to do this in the past (i.e. install a conventional FD) on my HT with cable running down the seat tube. Even though it's a dual pull, the conventional high clamp cabling will look a little ugly because it angles out and away from the frame down to the derailleur. At least, it looked ugly to me. So I tossed that idea and went back to a top swing (low clamp).

 

The way some get around that is to have this setup: