wheels78

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

Retro Grouch 

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?

Jeff Wills

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.

Kimmo

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.

Jeff Wills

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.

fietsbob

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..