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Upgrading Front Derailleur on 07 Stumpy FSR Question?

3K views 9 replies 6 participants last post by  nebula8080 
#1 · (Edited)
I’m planning to upgrade my Front Derailleur to XTR (including some other parts too) on my 07 Stumpjumper FSR elite.
I almost place an order for the “Conventional (Down Swing) Front Derailleur M971” before I saw LBS 07’ S-Work Stumpjumper FSR with “TOP SWING Front Derailleur M970”. My guess is that Frame geometry of the standard stumpy and the S-work to be almost the same, but why one down-swing and the other top swing? I suppose mine should work with Top-Swing too?
Any advantage?

So, should I purchase the Down-Swing or Top-Swing (if using XT or XTR Crankset)?

I'm attaching picture of the stock derailleur (Down-Swing).
 

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#2 ·
You have to watch the way they mount on the frame. I think a bottom swing will be to low and the Derailleur will hit the frame when the suspension bottoms out. I had a bottom swing on my FSR XC Pro that I tried to use on my 07 Stumpy Expert and ended up buying a new top swing XT Derailleur.
 
#5 ·
You can use either mount....

top swing or bottom swing on the 07 Stumpy FSR aluminum bikes. In previous years, 06 and older, the way the connecting yoke between the upper and lower seat tubes was formed and placed required the use of the top swing design as it would not allow proper placement of the higher clamp height of the bottom swing (traditional design) derailleur. The 07 models use a differently shaped and placed yoke that will allow the clearance needed for the higher clamp of the bottom swing derailleurs. My best advice is to go with the same clamp style that is currently on your bike. There are no real advantages or disadvantages to either style.

The reason the Sworks carbon bikes use the top swing design is there is a buldge at the appoximate height on the seat tube yoke interface that is right about where a bottom swing derailleur would need to be clamped. That bulge is there for added strength at that point of the lower portion of the seat tube. What you likely saw was a carbon Sworks. Both the Pro Carbon and Sworks carbon bikes come with top swing front d's for this reason. All the aluminum Stumpy's for 07 are speced with bottom swing fronts so no problem.

Good Dirt
 
#8 ·
I would spend the money elsewhere as well, I have a 10 year old LX front derailleur on my race bike and its perfectly fine, my Stumpy Elite has an 07 one and it's also more than fine. Put the money towards a new wheelset as thats where money spent makes a noticeable difference.
 
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