Mountain Biking - front derailleur question

What are the differences between these 2? and which is better?


One (http://www.jensonusa.com/store/product.asp?number=13053)
Two (http://www.jensonusa.com/store/product.asp?number=13054)

by the way i have an Alivo with top PULL(sorry) and the size is 34.9mm / 1 3/8'

Te first XT der you linked to is a top swing der. The second one is a bottom swing der.

Yep, each one is designed to work for a specific application. Many full suspension bikes have limited areas in which to mount a bottom swing derailleur (TWO- either top or bottom pull), so they go to a top swing (ONE).

If you've got a standard diamond shaped frame with a full length seattube, you can use either, but a bottom swing is usually best!

L8R

Originally posted by a2psyklnut
... a bottom swing is usually best!

Why's that?

The way the springs and linkages are set up it's a cleaner system. I guess really the differences are insignificant, but I've just always theorized that the bottom swing has a mechanical advantage. I could be wrong, (not the first time, not the last).

L8R

I've always wondered why the top swing models are more expensive. For example, the XTR FD961/962 is $60 vs. $90 for the bottom vs. top swing models respectively.