Recently bought a secondhand Hollowgram crankset to lighten up my 2014 CAAD10 with Ultegra 11 speed. After the install the clearance between the crankarm and front derailleur is incredibly tight, probably under 1 mm total and I've had to dramatically adjust my FD limits to clear the crankarm, causing a lot of chainrub against the cage in the process depending on the gearing. The crankarms are also fairly close to the chainstays as well, but within 4-5mm on both crankarms which seems acceptable given the low Q-factor of the crankset. The drive-side crankarm actually came with marks on the backside that look like it's had an issue with front derailleur rub in the past. Both crankarms look to be about even/not bent when compared to their alignment with the chainstays.

Does anyone have any advice? Hollowgram SL crankset on the 104mm spindle, bearing shield only on the non-drive side. No additional shims on the drive side either, just the wave washer. Using the 34/50 compact rings transferred over from my FSA SL-K Light crankset I had on the bike previously.

I've looked around past WW posts and only found some people's concern with this cranksets clearance on the chainstays, but never seen an issue like this with the front derailleur. Is it possible the Hollowgram SL just isn't compatible with Ultegra 6800's front derailleur or is something else up?

Here's a collection of (poorly shot) images while I had it up on the stand in the local shop today: http://imgur.com/a/AIIno

Why aren't you using a bearing shield on the drive side? Are you getting adequate wavy washer compression? Your shift cable is routed wrong - is the FD setup correctly?

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CAAD10 Di2

Sorry, no shims but there is a bearing shield in addition to the wave washer on the drive side. Wave washer looks like it's adequately compressed but not smashed. FD is set up correctly as far as I know (shop mechanic checked it today, after the photo he also fixed the cable routing issue that was from a mechanic at the shop I bought the bike from)

Maybe the 109mm spindle would solve your issues.

Based on those images. even if you took the existing spindle to a local machine shop to have the ridge removed, which would provide more flexibility in how lateral spacing is achieved, if drive side spacing is increased, non-drive side will be decrease even further. For that reason, I am going to agree with the previous suggestion about swapping the spindle for the 109mm SiSL2 road spindle as that stock 104mm road spindle lacks the clearance required to work with that frame.

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Michael - The Anaerobic Threshold is neither...

The 109 mm spindle won't solve anything other than increasing crank arm frame clearance. But 4-5 mm should be enough.

The front derailleur rubbing could be cause by a couple things
- bent crank arms
- bent spider
- incompatible chainrings (spaced too close to arms)
- improper front derailleur set up (limit screws)

Can you provide a head on picture of the front derailleur? In the big ring and smallest cog.

Yeah, I'll take a picture later today when I'm home and put it up.

-I don't think the crank arms are bent (based on equal spacing from frame and a visual inspection of the arms against a fixed object (basically, making sure they're both straight in the same ways).
-The spider could be bent as the chainrings weren't exactly flush against it when mounting them, but I wrote that off as just chainrings not being perfectly round. It was also suggested the spider could be installed backwards (if that's possible on a hollowgram spider?), pushing the rings towards the crank arms instead of the frame. Edit: talked to the seller, it's a new spider so it shouldn't be bent, but I'll check it later today.
-Not sure on chainring compatibility- they're just the 11 speed compact rings off my FSA SL-K light cranks.
-I don't think it's the limit screws as they've been set and reset repeatedly by two different mechanics now to try to work with the cranks, although even in the current "optimal" setup I'm still getting a lot of chain/cage rub.

I have the Hollowgram SL setup on my 2013 CAAD10 and it required a 109mm spindle.

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2013 Cannondale CAAD10