Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 03-31-12, 04:14 PM   #1
wheels78
Senior Member
Thread Starter
 
Join Date: May 2010
Bikes:
Posts: 63
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
XT shifters with a Dura Ace FD

I think the industry says that this does not work (MT bike shifters pull more cable then road bike shifters) but I seem to remember some people saying that they had done it and it works. Anyone here that has done it?

I've got two FD's that I picked up used. A XT M761A and a Dura-ace 7803 (triple). The D.A looks so much simpler and sleek. It's also around half the weight of the XT so I would really prefer to use it. I guess (when I get the rest of the parts that I need) I could just give it a try and see, I thought I would ask here and see if anyone thinks it'll work ok. If everyone say's "forget it, it won't work" then I'll just go with the anvil, ah, XT.

Thanks,
Bob
wheels78 is offline   Reply With Quote
Old 03-31-12, 06:48 PM   #2
Retro Grouch 
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Bikes: Rans Rockst (Retro rocket) Rans Enduro Sport (Retro racket) Catrike 559, Merin Bear Valley (beater bike).
Posts: 26,541
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 60 Post(s)
I can tell you for sure that, in the last century, mountain bike shifters paired with road bike front derailleurs used to be a common factory spec on tandems.

Since you already own the parts, I'd try the DA front derailleur and see if I could make it work. What do you have to lose?
Retro Grouch is offline   Reply With Quote
Old 03-31-12, 09:41 PM   #3
Jeff Wills
Insane Bicycle Mechanic
 
Jeff Wills's Avatar
 
Join Date: Mar 2008
Location: other Vancouver
Bikes:
Posts: 7,912
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Quote:
Originally Posted by Retro Grouch View Post
I can tell you for sure that, in the last century, mountain bike shifters paired with road bike front derailleurs used to be a common factory spec on tandems.

Since you already own the parts, I'd try the DA front derailleur and see if I could make it work. What do you have to lose?

The shifter.
Since the "mountain" shifter pulls more cable than the "road" derailleur is supposed to accept, the shifter won't click into position before the derailleur runs out of travel. The OP can cobble it together if he's running a double chainring and lets the cable have some slack in the small chainring position. If it's a triple chainring, it depends- the XT will work with smaller chainrings, while a "flat-bar" front derailleur (FD-R453 or FD-R773) is needed for road-size chainrings.
__________________
Jeff Wills

Comcast nuked my web page. It will return soon..
Jeff Wills is offline   Reply With Quote
Old 04-01-12, 12:04 AM   #4
Kimmo
bike whisperer
 
Kimmo's Avatar
 
Join Date: Dec 2009
Location: Melbourne, Oz
Bikes: copy/paste links: http://velospace.org/node/36949 http://velospace.org/node/47746 http://velospace.org/node/47747
Posts: 7,099
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
If it doesn't work, you could try routing the cable on the other side of the pinch bolt to change the actuation ratio.

If you can get it closer to the pivot, voila: suddenly it requires more cable travel. Whether the indexing will be close enough then, well...

IMO only Campy has figured out the right way to front shifting post-indexing, with their microratchet or whatever it's called - essentially a friction system. Front indexing is just made of fail, IME.
Kimmo is offline   Reply With Quote
Old 04-01-12, 11:12 AM   #5
Jeff Wills
Insane Bicycle Mechanic
 
Jeff Wills's Avatar
 
Join Date: Mar 2008
Location: other Vancouver
Bikes:
Posts: 7,912
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Quote:
Originally Posted by Kimmo View Post
If it doesn't work, you could try routing the cable on the other side of the pinch bolt to change the actuation ratio.

If you can get it closer to the pivot, voila: suddenly it requires more cable travel. Whether the indexing will be close enough then, well...

IMO only Campy has figured out the right way to front shifting post-indexing, with their microratchet or whatever it's called - essentially a friction system. Front indexing is just made of fail, IME.
Nope, wrong direction. The shifter pulls more cable than the "road" derailleur is designed for. You need to have a longer lever arm, not shorter. In fact, that's how the FD-R453 derailleur is different- the arm that the cable bolts to is longer than the "road" version.
__________________
Jeff Wills

Comcast nuked my web page. It will return soon..
Jeff Wills is offline   Reply With Quote
Old 04-01-12, 12:55 PM   #6
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 18,840
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 222 Post(s)
Shimano's brifters go ka-thunk, over a chainring, and you cope with the chain angle changing
as it moves from low to high.
no fine tuning after the shift . so some scraping of chain against the wider may result.
the shape of the cage tries to reduce this...

so I am glad I don't use them, myself, on my own bikes.
Do my coping on OP's bikes, in the shop.

lots of Mountain FD, now are fitting the cable anchor below .
a PIA to fuss with..
Old school, I prefer the cable bolt above the Pivot and cage..

Last edited by fietsbob; 04-01-12 at 12:59 PM.
fietsbob is online now   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 10:55 AM.