Front Derailleur Help - Chorus 11 on Ritchey Logic Cranks

[Peter P.]

I still think andy should try an earlier vintage ATB front derailleur. The deeper, inner cage plate contours might help pick up the chain earlier, working better with that wide differential chainring setup. Experimenting with a shorter drive side crank axle spec would be an alternative solution.

[andy.mgnr]

Originally Posted by Peter P.

I still think andy should try an earlier vintage ATB front derailleur. The deeper, inner cage plate contours might help pick up the chain earlier, working better with that wide differential chainring setup. Experimenting with a shorter drive side crank axle spec would be an alternative solution.

Thanks, per your suggestion I swapped on an old Deore triple FD from my commuter and its actually somewhat working! Tested it on the road and the shifting into the big ring is still very rough though, and half the time takes quite a few rough grinding pedal strokes while the chain skips and attempts to latch onto the teeth.

Definitely a step in the right direction though - still awaiting a wider FD clamp in the mail to try that as well.

[m_sasso]

Originally Posted by andy.mgnr

Thanks, per your suggestion I swapped on an old Deore triple FD from my commuter and its actually somewhat working! Tested it on the road and the shifting into the big ring is still very rough though, and half the time takes quite a few rough grinding pedal strokes while the chain skips and attempts to latch onto the teeth.

Definitely a step in the right direction though - still awaiting a wider FD clamp in the mail to try that as well.

Just a thought. Might want to give a diffrent brand chain a try, can't tell what chain you are using however it might have some limited compatibility with the pick up pins on the TA chain rings you are using.

[Peter P.]

Rough shifting should be expected with such a large difference between your chainrings. Try to envision this: If you were running a half-step plus granny triple or just a half-step double chainring setup, with a say, 7 teeth or less difference between chainrings, front shifting would be incredibly easy.

The inner cage plate of a front derailleur, particularly a triple, is positioned relative to the outer cage plate (notice they're not twins as to their profiles and positions) to lift the chain from the tail end onto the next largest chainring.

My suggestion to use an older, triple compatible front derailleur was based on the fact that your chainring difference was similar to what would be seen had your crank had all three rings. Typically, those triple front derailleurs will work with a large-middle chainring difference of 12T.

Lastly, I'm sure you know the recommended setup for a front derailleur is to have the outer cage plate parallel to the face of the large chainring.

Glad to hear you're experiencing at least some improvement in shifting. Don't forget to verify your chainline and perhaps consider reducing the difference between your chainrings. Your other option would to actually add the third chainring (and change the chainline) with that middle ring reducing the vast difference and being a sort of stepping stone to the large ring. I suppose it's also quite possible the newer, recent vintage double chainring front derailleurs are made to handle the wider range compact front chainring setups like you're using. Those new derailleur cage shapes may actually be duplicates of your better working Deore, but in disguise as "new" tech!

[David Benson]

Originally Posted by Mark McM

You mention the drivetrain components, but you don't identify the frame. .

From the earlier thread about ths debacle, the frame is a 90s Ritchey Road Logic which is neither slack or low

[David Benson]

Originally Posted by andy.mgnr

Hmm you might be onto something - I’ve got the skinniest BB I could get but I still have to tighten the lower limit screw in all the way to get it over enough. Unfortunately I’ve got a 26.8 downtube and it’s tough finding a clamp that will work :/

What bottom bracket are you using?

[Mark McM]

Originally Posted by David Benson

From the earlier thread about ths debacle, the frame is a 90s Ritchey Road Logic which is neither slack or low

Then why is the derailleur further back from the top of the chainring on the OP's bike than usual? Bases on the photos, the front of the Chorus derailleur cage is about 1 3/4" inches behind the top of the chainring, while the same derailleur in the photo below is about 1 1/4" behind the top of the chainring. Also note that the Deore derailleur that the OP reports has better shifting has an inner plate that extends further forward than the Chorus derailleur.

[David Benson]

Thoughts:
-is it just impossible with my crankset setup?

I have had no success using the same crankarm and TA chainring combo with Campagnolo 10 speed.
Im pretty sure this is because the Campagnolo front derailler does not work effectively when the chainline is significantly rightwards of the 43.5mm chainline that Campagnolo specifies. It is impossible to achieve 'correct' chainline using Logic Compact cranks and any bottom bracket.
The same front derailler shifts satisfactorily on a Ritchey Logic 110pcd crank with TA 48/33 rings. With a 108mm JIS BB this crankset has a standard chainline.

This is an archaic diagram but the chainline dimension shown is the same as Campagnolo 11 speed:




-is there a way to adjust the leverage or throw of the FD arm? I’ve got the cable correctly routed around the top of the tab

No, but these might help:
1/ a SRAM 11.7615.011.000 front derailler angle washer will lower the tail of the derailler cage
2/ Campagnolo front derailler clamps position the derailler forward than the aftermarket clamps that I have tried. I am using the DC12-RE2B 32mm clamp with a shim to fit the 28.6mm seat tube.
Here's a terrible photo of my Campagnolo front derailer & clamp with the SRAM angled shim, 48/33 rings:



I have just switched to a Shimano 105 FD5800 front derailer, as recently made famous in a similar application on the Radavist, still using the SRAM shim and Campagnolo clamp.
Shifting is definitely faster than the Campagnolo derailler, and Im optimistic it might work over the wider chainline of my Logic Compact cranks but have not had time to try it yet.

-I do remember thinking it was weird but when installing my cable the barrel at the end didn’t drop into or recess into the plastic ratchet mechanism inside the shifter body, but instead just sat on top. I tried and poked around to see but it really didn’t seem like there was a recess it could drop into. Could that be an issue?

Seems like an issue, but a different one.
Is it a Campagnolo cable? The barrell on most other brands is larger than Campagnolo, and if you get it to seat in the recess you wont get it out later. [/QUOTE]

[David Benson]

Originally Posted by Mark McM

Then why is the derailleur further back from the top of the chainring on the OP's bike than usual? [/IMG]

Because the aftermarket derailler bracket puts it there.
I have been through this on a couple of bikes and found that the Campagnolo clamps position the derailler further forward relative to common inexpensive aftermarket clamps.

[truth]

I had the same symptoms as you with a bike that had a large BB drop with a slack seat angle and it was exacerbated by using a subcompact crank with a wide range cassette.

I tried a number of derailleurs and derailleur clamps. I tried the angle shim which helped me get a lower derailleur height but made things worse by moving the derailleur further back.

I ultimately made a functional but hideous clamp that moved the derailleur forward and mounted it at at a steeper angle which worked a charm.

Maybe you could make something like this or have someone make somthing similar.

[David Benson]

Originally Posted by truth

I had the same symptoms as you with a bike that had a large BB drop with a slack seat angle and it was exacerbated by using a subcompact crank with a wide range cassette.

I tried a number of derailleurs and derailleur clamps. I tried the angle shim which helped me get a lower derailleur height but made things worse by moving the derailleur further back.

Not saying your solution would not help, but this frame is not slack or low.

[andy.mgnr]

Hey guys thanks a ton for all of the help!! To answer a few questions:
-102 ISO Campy BB
-Shimano 105 11 speed chain (all the LBS had and wanted to support the new local shop)
-Correctly stated its a 1993 Ritchey Road Logic

I appreciate you guys helping me try to make this dumb combo work, I believe tinkering with stuff like this is what its all for right?

I just got my SRAM wide chainline derailleur clamp in and swapped back on the Campy Chorus FD and on the stand it seems to have helped alot! It looks to me as if it helps alleviate the tail up issue we were seeing, which means it was probably my cheap FD clamp that was to blame for the angle. Similar if not a bit better shifting over the old Deore, but seemingly a higher propensity to shift the chain over the big cog and drop - its a very fine line on the upper limit screw (I'm talking a quarter turn) between having it able to shift up at all versus overshifting. I believe I have it as close as I can for now and am going to take it on a test ride tonight to see how she goes - will report back!

[andy.mgnr]

Seems like an issue, but a different one.
Is it a Campagnolo cable? The barrell on most other brands is larger than Campagnolo, and if you get it to seat in the recess you wont get it out later. [/QUOTE][/QUOTE]

It is indeed a Campy cable from the official Campy housing and cable kit. I will double check it again but I really looked and tried and it didn't seem as though there was any recess to drop into! I will try and get a pic.

Also let me know if you ever try the 105 FD on your Logic Compacts! I'd be curious to know if this helps - so far it seems the main issue is the wider chainline and using a wider FD clamp seems to be the only solve so far.

[oldpotatoe]

Originally Posted by andy.mgnr

Seems like an issue, but a different one.
Is it a Campagnolo cable? The barrell on most other brands is larger than Campagnolo, and if you get it to seat in the recess you wont get it out later.

[/QUOTE]

It is indeed a Campy cable from the official Campy housing and cable kit. I will double check it again but I really looked and tried and it didn't seem as though there was any recess to drop into! I will try and get a pic.

Also let me know if you ever try the 105 FD on your Logic Compacts! I'd be curious to know if this helps - so far it seems the main issue is the wider chainline and using a wider FD clamp seems to be the only solve so far.[/QUOTE]

There is a 'recess' in the take up spool but it isn't a great big one that the cable end 'pops' into..more like a wee shelf.

[andy.mgnr]

[/QUOTE] There is a 'recess' in the take up spool but it isn't a great big one that the cable end 'pops' into..more like a wee shelf.[/QUOTE]

Thanks this sounds exactly like what I remember - it definitely seated on something but didn't fully recess like I recall the rear shift cable doing in its shifter.