Front Derailleur Help - Chorus 11 on Ritchey Logic Cranks

[andy.mgnr]

Took the bike out for its first ride last night and it rode absolutely amazing... except for the front shifting of course. Was able to grind my way into a few front shifts but had a couple really bad chain drops and that gets old reaaaaal quick. Definitely looking for a better solution.

Originally Posted by David Benson

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 just ordered an Ultegra FD-R8000 as a final test after reading that Shimano might actually shift better with Campy 11, and this particular model is supposedly made for wider range and wider chainline popular on new gravel/road disc models with 135-143 rear spacing. If this doesn't improve overall shifting I might throw in the towel on this crankset dream and find a similar 110bcd vintage double that I can throw some similar extralite rings on for a comparable aesthetic

[Mark McM]

Originally Posted by andy.mgnr

I just ordered an Ultegra FD-R8000 as a final test after reading that Shimano might actually shift better with Campy 11, and this particular model is supposedly made for wider range and wider chainline popular on new gravel/road disc models with 135-143 rear spacing. If this doesn't improve overall shifting I might throw in the towel on this crankset dream and find a similar 110bcd vintage double that I can throw some similar extralite rings on for a comparable aesthetic

I have tried an Ultegra FD-R8000 front derailleur with Campagnolo 2015+ 11spd shifters, and found that they really weren't compatible. The FD-R8000 is designed for a much shorter cable travel than Campagnolo derailelurs, and it is has a very stiff spring. This results in a higher lever force to pull the cable, and the index detents may not hold in all cases. The cable travel difference is so great that the Campagnolo shifter trimming detents will become ineffective, and you won't be able to trim the derailleur to eliminate cable rub.

As it happens, I have these same cranks, used as a triple on an MTB. My cranks are mounted with a 118mm long spindle, and the chainline to the mid-point between the outer and middle chainrings is about 53.5mm, which is about 10mm more than a typical road chainline. So to reduce the chainline to 43.5 I'd have to use a spindle 20mm shorter, or about 98mm. The shortest common spindle length is 102mm, so the narrowest practical chainline is about 45.5mm, which is wider than standard for road. So these cranks really aren't well suitable to be used as a double crank on a road bike. So the question is, why are you so wedded to cranks that may take extreme measures to work on your bike, when there are many better suted options?

[andy.mgnr]

Originally Posted by Mark McM

I have tried an Ultegra FD-R8000 front derailleur with Campagnolo 2015+ 11spd shifters, and found that they really weren't compatible. The FD-R8000 is designed for a much shorter cable travel than Campagnolo derailelurs, and it is has a very stiff spring. This results in a higher lever force to pull the cable, and the index detents may not hold in all cases. The cable travel difference is so great that the Campagnolo shifter trimming detents will become ineffective, and you won't be able to trim the derailleur to eliminate cable rub.

Shoot we’ll that’s a bummer to hear…

And thanks for the info, yeah I’ve already been through trying to find the skinniest BB possible and am at a 102 iso that has me close but obviously still causing issues.

As far as this specific crank I obviously wanted a ritchey crank for the ritchey logic road build and wanted something vintage to keep the look of the bike from being too modern - I also wanted something with a small BCD to allow for a wide range of chainring options, which is harder to find with vintage cranks especially ritcheys. But also I think on this forum we all have our affinities for certain components and this specific crank is one of my favorites and I always wanted to try and get it on a build. It seems like it’s probably just not going to work unfortunately and I’ll most likely be looking for a similar vintage 110 bcd road double option.

[Mark McM]

Originally Posted by andy.mgnr

As far as this specific crank I obviously wanted a ritchey crank for the ritchey logic road build and wanted something vintage to keep the look of the bike from being too modern - I also wanted something with a small BCD to allow for a wide range of chainring options, which is harder to find with vintage cranks especially ritcheys. But also I think on this forum we all have our affinities for certain components and this specific crank is one of my favorites and I always wanted to try and get it on a build. It seems like it’s probably just not going to work unfortunately and I’ll most likely be looking for a similar vintage 110 bcd road double option.

The crankset you are trying to use is a low-profile MTB crankset, with a 94mm/58mm BCD. Ritchey also sold 110mm BCD double road cranks and 110mm/74mm BCD triple road cranks, both of which should work fine with a standard road drivetrain. (In fact, this crank is a somewhat high profile crank, so if mounted it to a 102mm spindle the chainline would be too narrow). The 110mm BCD would limit you to a minimum chainring size of 33 teeth, but you could also fit the Bikingreen 46/30 chainrings. Or, with a longer spindle, you could use a triple crank as a double with chainrings in the "middle" and inner positions, which would allow chainrings down to 34/24. (Note that the only difference between the Ritchy 110mm BCD double and 110mm/74mm triple cranksets is that the triple crankset has 74mm BCD holes drilled in the spider arms, while the double has undrilled "nubs" where the inner chainring would have mounted - in other words if mounted only the two outer chainrings, the triple crank would be functionally identical to the double.)

While I haven't used a Ritchey 110mm BCD crank with an 11spd drivetrain, it worked fine with a 9spd Campagnolo drivetrain. With the appropriate chainrings, I have no doubt it would work with an 11spd drivetrain as well.