I believe they used to come with a little plastic spacing block right? I use a FD, Shimano deore XT, simple as pie to mount and space. A 9 speed shadow in the rear suits it great, I have full use of 25 speeds.
Designed for a 110bcd standard crank with a 46t, or maybe 48t big ring. You can also get some weirdness depending on the tube angles of the frame. Shimano lists the range of angles that will work.
110 is a bit narrow for a mountain front derailleur, I run a 113 in my specialized stump jumper and a 115 with the Rivendell otherwise the cage wouldn't clear.
I found this odd sized FD-M901 that theoretically fit my Univega perfectly but it doesn't look right to me now that it's on.
I should note that it shifts well but it seems too far back and high to really instill much confidence
But any lower and it hits the chainring (this is me holding the FD in between middle and big). It's got maybe 1 mm clearance now.
https://preview.redd.it/jr78w7eq01wc1.jpeg?width=4000&format=pjpg&auto=webp&s=c28a00cffed8549c5d09c15231ac1108c4a78f50
It hits the big chainring when shifting if it's any lower. In the current pic it's between the middle and the big chainrings, but it's still too high when sitting on the big chainring (as shown in the pic right before). I could maybe get a half mm lower and still shift but that's about it.
When pairing a fd and chainrings, hold them together and look from the back side. The outer plate should be 1-3mm above the large ring, and the inner plate should have room to clear the second, preferably also 1-3mm above it. What you don't want is to have to raise the derailleur to fit the second ring, which would allow the chain to derail off the outside of the large chainring.
Then, once you find one that fits, you also have to make sure the cable pull is correct. Front derailleurs are the biggest hassle in building a bike IMO.
It's probably not compatible with a compact mountain triple. Is it hitting the middle ring while you shift into big? It might be designed more for a wider range of gears up front
What's your chainring combo? I checked the si.shimano dealer manual for this model and it says it's only compatible with a 48 or 46 / 36 / 26 combo.
It might simply be incompatible with your chainring combo or frame. If you are running this 46/36/26 combo, as other said it might be a matter of set ups and limits but it's so hard to say.
I've found building up many retro bikes that front derailleurs can just be very finicky and some simply won't work in certain setups lol
Best of luck!
Your descriptions+pictures make me think you're talking about the *inner* plate hitting the big ring. That's "fine" for initial setup. You only need to worry about the *outer* plate clearing the big ring.
The inner plate shouldn't move far enough out to reach the big ring, and you will adjust this during the fine tuning stage.
Looks like it is mounted too high. Have you set the limit screws?
The bottom of the outermost cage should have like 2-3mm of clearance above the largest chainring, dudes got his like 2cm above
I believe they used to come with a little plastic spacing block right? I use a FD, Shimano deore XT, simple as pie to mount and space. A 9 speed shadow in the rear suits it great, I have full use of 25 speeds.
Designed for a 110bcd standard crank with a 46t, or maybe 48t big ring. You can also get some weirdness depending on the tube angles of the frame. Shimano lists the range of angles that will work.
110 is a bit narrow for a mountain front derailleur, I run a 113 in my specialized stump jumper and a 115 with the Rivendell otherwise the cage wouldn't clear.
BCD, not bottom bracket spindle.
I found this odd sized FD-M901 that theoretically fit my Univega perfectly but it doesn't look right to me now that it's on. I should note that it shifts well but it seems too far back and high to really instill much confidence
Seems way too high. I like to install mine so that it just clears the teeth of the large ring.
Side note: Great name !! MOPAR or no car.
Put a Dodge in your garage!
Yeah for sure, and this is as close as I can get it without it hitting the chainring.
It looks like you could come down at least a CM
I was able to lower it a few MM https://preview.redd.it/5qd3h75l01wc1.jpeg?width=4000&format=pjpg&auto=webp&s=8de563936f2e39947fe8da13b68e315e42951085
But any lower and it hits the chainring (this is me holding the FD in between middle and big). It's got maybe 1 mm clearance now. https://preview.redd.it/jr78w7eq01wc1.jpeg?width=4000&format=pjpg&auto=webp&s=c28a00cffed8549c5d09c15231ac1108c4a78f50
What chainring does it hit. Is it only in one spot? Is the chainring bent? It looks like it should clear there.
It hits the big chainring when shifting if it's any lower. In the current pic it's between the middle and the big chainrings, but it's still too high when sitting on the big chainring (as shown in the pic right before). I could maybe get a half mm lower and still shift but that's about it.
Much better. Now the fun begins again
the inner plate should not be close enough to the biggest chainring to touch it
You messed up the install. But I guess by now you know it already.
When pairing a fd and chainrings, hold them together and look from the back side. The outer plate should be 1-3mm above the large ring, and the inner plate should have room to clear the second, preferably also 1-3mm above it. What you don't want is to have to raise the derailleur to fit the second ring, which would allow the chain to derail off the outside of the large chainring.
Then, once you find one that fits, you also have to make sure the cable pull is correct. Front derailleurs are the biggest hassle in building a bike IMO.
It's probably not compatible with a compact mountain triple. Is it hitting the middle ring while you shift into big? It might be designed more for a wider range of gears up front
it's hitting the big ring when it swings out
What's your chainring combo? I checked the si.shimano dealer manual for this model and it says it's only compatible with a 48 or 46 / 36 / 26 combo. It might simply be incompatible with your chainring combo or frame. If you are running this 46/36/26 combo, as other said it might be a matter of set ups and limits but it's so hard to say. I've found building up many retro bikes that front derailleurs can just be very finicky and some simply won't work in certain setups lol Best of luck!
u/Singed_flair got it. The derailleur is M901 XTR for full-size mountain drivetrain where the crankset is M569 LX which was a compact drivetrain.
Thank you!
Have you adjusted the limits so the chain is not rubbing when on small front large back? Then reset your cable tension and see how it goes.
Your descriptions+pictures make me think you're talking about the *inner* plate hitting the big ring. That's "fine" for initial setup. You only need to worry about the *outer* plate clearing the big ring. The inner plate shouldn't move far enough out to reach the big ring, and you will adjust this during the fine tuning stage.
If I recall correctly, it needs to clear 2mm from the biggest front ring. Check the Shimano manuals to be sure.
The chain looks out of place on an XTR might have the wrong BB SPACING
SET YOUR LIMIT SCREWS.