Don't crosschain.

I don’t. I tested the tolerance to evaluate the installation.

Scott

What brand/model is the front derailleur?

Shimano DA

This is a BB30 Quark? Compact or standard rings? You sent in an Elsa R with carbon crank arms and received the exact same crankset in return? I wasn't sure Quarq even stocks replacement Elsa spiders since the update to the DZero models. Did you receive new chainrings or were your old ones reinstalled?

When I had a couple of S975 GXP compact cranks updated to Elsa R's something in the combo of new cranks and chainrings changed clearances at the extreme ends of the chainring and cog combos. Not sure if it was a 10/11 chainring or spider spec difference (rings were still 10s) but crosschain from small front ring to smaller cogs rubbed chain and big ring to larger couple cogs would drop chain if backpedaled even slightly. This just took more vigilance to stay away from extreme ranges.

For ur install to BBRight you just used the 11mm spacer on the DS of the spindle? Same one you took off or a new one? Did you have to change anything up on NDS from what was installed before? Typically a wave washer and maybe a thin plastic shim or two for Quark BBRight. If all these were reused and you didn't replace BB, then no install error and so,etching just changed slightly with the Quarq spider or ring specs.

What model number?

Did you put the spacers back in the same way? Are the spacers the same as before?

Are there new dust shields?

Personally I wouldn't be surprised at all if I installed new crank of the same model and had to make a small front derailleur adjustment.

“crosschain from small front ring to smaller cogs rubbed chain and big ring to larger couple cogs would drop chain if backpedaled even slightly“

This is exactly my situation! Thanks for the feedback.

I’ll do my best to answer the questions from you and the others. Again, looking to learn here so let me know what I may have missed.

My drivetrain:
-Cervelo NP3
-Shimano Dura-Ace 9000 11 speed mechanical group-set
-Wheels Mfg BBright bottom bracket
-Quarq Elsa RS GXP spider
-165mm Quarq GXP DZero cranks
-50/34 DA9000 chainrings

The process:
-Removed non-drive crank, noting no spacers
-Removed remaining crank-set from bottom bracket, noting no spacers
-Shipped assembled drive-side crank-set, including spindle, 172.5mm crank, spider and chainrings to Quarq
-Quarq removed the 172.5mm crank and spindle, replaced it with a 165mm crank and spindle and recalibrated the power meter
-Quarq shipped the reassembled crank-set, including original spider and chainrings and new 165mm crank and spindle to me, along with a new 165mm non-drive crank.
-I reinstalled the crank-set by inserting the spindle through the bottom bracket and attaching the new 165mm non-drive crank, unfortunately by feel as I don’t have a torque wrench capable of 54nm spec

Basically, Quarq swapped the drive-side crank and sent the assembled crank-set back to me for reinstallation. Everything is exactly the same, except the cranks went from 172.5mm to 165mm. Unless the spindle has some potential variance?

Scott

Ah ok, the Elsa RS is a different animal than the Elsa R. Shimano chainrings and the fact your using the previous set should eliminate ring differences as an issue. The RS bolts up the same as the new D-Zeros with 8 bolts connecting the spider to the crankarm. There should be nothing different with your new shorter cranks. You could always drop Quarq a note and ask if there is any known offset difference with the crank arms they are now using.

GXP in a BBRight install is different than the BB30 Quark install I outlined earlier. Is your Wheels Mfr BB their direct conversion installation with the DS shell and bearing sitting outboard of the frame? Or is it their PF30 style combined with conversion bushing adapters? The former should be easy to identify as the aluminum shell extends out of the frame and you should be able to see the inner bearing races while the latter has plastic bushings pressed into the inner bearing races on each side.

Wheels Mfr install instructions show using a wave washer and shims outside of bearing shields/seals with the conversion BB. Missing the wave washer or one of the shields/seals on the DS could shift the crank install enough to throw off FD adjustment. The GXP wave washer sticks pretty tight on the crank spindle up against inside of spider, so it could have been easy to miss when you pulled the cranks. Bearing shield could also come off the same way, but are usually red orange and hard to miss.


http://wheelsmfg.com/...EC3-INSTRUCTIONS.pdf

If you have the PF30 and conversion bushings the stock install doesn't show a wave washer and shims are only used if necessary. With this setup the shields/seals are inboard of the converters, so no chance to miss putting one back.

I would sweat the torque wrench for GXP. The torque is so high that it is essentially a crank it until it stops install.

“Is your Wheels Mfr BB their direct conversion installation with the DS shell and bearing sitting outboard of the frame? Or is it their PF30 style combined with conversion bushing adapters?

The former should be easy to identify as the aluminum shell extends out of the frame and you should be able to see the inner bearing races while the latter has plastic bushings pressed into the inner bearing races on each side.”

I’m googling images in an attempt to answer this conclusively. Based on your description, I’d guess the PF30style. All I recall seeing is black plastic/rubber.

Scott

Here is the outboard BB - DS has toothed shell extension while NDS has toothed shell flush against frame:





And here is the PF30 adapter BB config:



If you have the PF30/adapters then there shouldn't be anything you could have missed on reinstall. So perhaps follow up with Quarq and/or adjust FD.

One additional thought. Can you move the crankset horizontally - pushing or tapping towards one side of bike or the other changes gap behind crank arm? This would indicate missing shims or washer from previous install.

Thanks! I definitely have the PF30.

I gave the cranks a good tug back and forth after installation, finding no movement in the crank-set.

I really appreciate your help, and am now reasonably confident I haven't royally screwed this up. There must be some subtle difference in the placement of the new setup.

I'm scared of my derailleur, but that is another story. Any adjustment seems to be a circle of destruction that leads me to the LBS. I may just manage the issue by keeping the chain straight and deal with it next time the bike is in the shop for whatever reason.

Scott