Gearing and FD set-up dilemma

[NHAero]

I changed my Anderson to a 2x11 hydro this year, using Shimano RS685 shifters, an R8000 rear derailleur and 11-34 cassette (altered to 12-34) and a CX-70 10 sp cyclocross FD (braze-on mount, bottom pull). I've been running an old Sugino AT 110mm BCD crankset with 44-33 TA chainrings. It was fussy to set up the FD but in the end it shifts well. Due to the location of the braze-on tab, there is 10mm of clearance between the chain guide of the FD and the teeth of the 44T chainring - the FD is at the bottom of the braze-on tab. There are adapters to lower the FD on a braze-on tab (I have one) but it doesn't work here, its highest position lowers it too much.

The 44T big ring with the 12-34 cassette means I rarely need to shift down to the 33T ring here on Martha's Vineyard. So I thought that if I could get a smaller inner ring I'd be better set up for riding in places with steeper and longer hills.

Yesterday I installed a SunXCD 50.4mm BCD crankset, very slightly used, with TA chainrings 44-28, not ramped and pinned. In the stand I can't get it to shift such that the chain guide of the FD doesn't rub the chain in some useful gears. Part of this issue is the runout of the TA chainrings (I set my Bob Jackson up with a TA Cyclotouriste crankset in 1972, 48-34, and had the same runout issue but shifting was friction so no big deal). I can likely mess with the chainring and bend it some, but I think I'm going to want the ramps and pins so a new big ring is order, and then I can either get a Velo Orange (only at 46T though) or a SunXCD 44T.

I'm wondering how best to work this out. These are the options I see:
- Try an R8000 11 speed FD, which has alignment adjustment the CX70 doesn't have, and brings 11 speed compatibility with the shifter
- Try a more rigid ramped and pinned 44T chainring (SunXCD)
- Bite the bullet and go with 46-30 instead of 44-28, and try a more rigid ramped and pinned chainring (Velo Orange - I like the look of that ring more than the clover patterned SunXCD). This reduces the gap between the chain guide and the teeth about 4mm
- A combination of the above

Thoughts very much appreciated

[Black Dog]

What about getting a FD braze on adaptor clamp and put on the seat tube right under the FD braze on. You can then keep the same FD you have and drop it low enough to close the huge gap.

https://www.sweetpetes.com/images/library/large/shimano-dura-ace-r9150-di2-front-derailleur-braze-on-adaptor-230650-1-11-1.jpg

[NHAero]

Thank you for that suggestion. As far as I can see, there isn't an adapter that doesn't put the new tab too low - either the clamp adapter as you suggest, or the Wickwerx one.

What about getting a FD braze on adaptor clamp and put on the seat tube right under the FD braze on. You can then keep the same FD you have and drop it low enough to close the huge gap.

https://www.sweetpetes.com/images/library/large/shimano-dura-ace-r9150-di2-front-derailleur-braze-on-adaptor-230650-1-11-1.jpg

[Black Dog]

Thats too bad. What about a triple FD. The FD can be set up as if your big ring is the middle and your small the small. The cages on the triple FDs drop much lower than a double FD.

[NHAero]

I think I'm going to try the R8000 FD with a 44T ramped and pinned chainring. I had a shimno triple FD on there to begin with and it didn't work at all.



Thats too bad. What about a triple FD. The FD can be set up as if your big ring is the middle and your small the small. The cages on the triple FDs drop much lower than a double FD.

[NHAero]

I decided to try the R8000 front derailleur first, so it shows up this week and I'll see if there is an improvement.
Any other thoughts?
Thanks

[Gummee]

Wickwerks and Rotor both make adaptors.

M

[NHAero]

I have the Wickwerx one and it would put the derailleur way too low. I see other on the Web but they look to have the same issue. I can't find the Rotor version on their web site - do you have a link?

Thanks

Wickwerks and Rotor both make adaptors.

M

[NHAero]

I was able to get the Wickwerx adapter to work, albeit with the chain guide now so low that it takes careful orientation and holding my breath to keep it from scraping the teeth of the large ring when in the small ring. Still not zero rubbing. I'm awaiting the R8000 fd, perhaps that will be an improvement. The chain guide just clears the chainstay, as well. The shift up to the non-ramped/pinned chainring is definitely acceptable, especially since with the 28T small ring, I don't expect to be going back and forth much. I still have to bear down and solve the runout issue, that may do the trick with the rubbing.

Is there a chance that shifting will improve if there was more clearance to the chainring, instead of clearing it by a hair? I could change the 44T to a 42T and pick up about 4mm. I'd change the 12T I swapped in to the cassette back to the 11T.

[oldpotatoe]

I think I'm going to try the R8000 FD with a 44T ramped and pinned chainring. I had a shimano triple FD on there to begin with and it didn't work at all.

Yup, that'll work. Shift the chain to the big ring w/o rub since you don't have to 'overshift' a bunch because the rings are pinned and such. PLUS..CX-70 and 11s front ders are all that's compatible with 11s shifters.

[NHAero]

After messing around with the chain dropping between the chainrings (https://forums.thepaceline.net/showthread.php?t=231569) I reversed the inner ring from its intended orientation and that worked. But the shifting still was less than I'd hoped for. I bit the bullet and bought the SunXCD rings, because the big ring is ramped and pinned. Even though both the TA ring and the SunXCD ring are both 44T, the Sun ring is marginally larger so the chain guide hits the teeth of the big ring. I jettisoned the Wickwerx adapter and set the fd as low as possible in the braze-on tab. At this point, it shifts very well. I have some fiddling yet to do, because in the lowest gear and the highest I have a bit of chain rub. Similar to the TA, the SunXCD chainrings have runout - I took the worst out but have some way yet to go. I think it's gonna work, though!
I appreciate the help from all you folks, and hope that my experience helps inform others' in the future.

I still haven't yet decided for me what the best way to get really low gears is. The Anderson is set up 11s with the 44-28 and a 12-34 cassette. 22-100 gear-inches. The drop bar Litespeed conversion has the 44-33 I had previously on the Anderson, with a 10s 11-40 cassette. Easier front shifting, but bigger gaps on the rear. 22-105 gear-inches. Changing the 11-40 10s to the same range but 11s puts a 17-19 instead of an 18 between the 15 and the 21 cogs, so likely a noticeable improvement.

[ultraman6970]

Dude needs something like this, when i saw the picture thought about filing the boss but the thing way too high to do it...

https://wickwerks.com/products/fit-link-adapter/

As an extra comment, just looking they have campagnolo compatible bolts and pretty much for nothing...

[NHAero]

If you read the posts in this thread, you'd see that I actually have one of these :-)

Dude needs something like this, when i saw the picture thought about filing the boss but the thing way too high to do it...

https://wickwerks.com/products/fit-link-adapter/

As an extra comment, just looking they have campagnolo compatible bolts and pretty much for nothing...

[Gummee]

I think at this point, I'd be looking for a bigger outer ring and bigger cassettes or breaking out the dremel and a hunk of AL and going at it to make something custom

Me being a lazy SOB, I'd likely look for bigger rings and cassette

M

[jtbadge]

I think at this point, I'd be looking for a bigger outer ring and bigger cassettes or breaking out the dremel and a hunk of AL and going at it to make something custom

Me being a lazy SOB, I'd likely look for bigger rings and cassette

M

+1. I run a SRAM 11-36 cassette on my RD-6800, I'd bet the R8000 should handle that no problem. Then run a 46-33 or whatever up front.

[NHAero]

I think my only issue now, which is resolvable, is the runout on the chainrings causing the rubbing. And it might be that the shoulder location where the rings seat on the crank, which is so minimal in diameter relative to a spider, is not 90 degrees to the axle axis. If so, I could possibly shim the ring to resolve. I wonder if the White Industries VBC crank, which also mounts the large ring directly to the crank down at the axle area, has less runout.

And yes, a larger ring and larger cog gets the same ratio, but with bigger gaps between gears, as I mentioned above, comparing with my Litespeed. But cranks with integral spiders have much less side to side runout so setting up the derailleur is easier.

+1. I run a SRAM 11-36 cassette on my RD-6800, I'd bet the R8000 should handle that no problem. Then run a 46-33 or whatever up front.