It's interesting how personal preferences can vary when it comes to bikes, and how technology advancements can lead to different opinions about what makes a "perfect" bike
Yeah, real happy with the bike so far, but the 12 speed DI2 not so much. So I cleaned the chain a couple weeks ago, and then went on a ride with the first serious hill climb where I needed the lowest gear. LOUD clacking in the two lowest. I got back, Googled a bit and found incomplete cleaning could result in clicking (that has never happened to me before.) I did a super deep clean with the Park tool mechanical scrubber where you clamp it over the chain, fill it with solvent and crank for a while. It seemed to help but there is still clicking on the big ring. Yes - I did test the functionality of all the gears when I rode it at the LBS and everything was fine. I'm not sure what the problem is. It could either be something is wonky with the big ring on the rear, or it still could be the chain. There is a serious, push it to the complete limit lateral deflection on the chain from the big gear and the back and the big ring on the front. Using the small ring in the front helps but doesn't solve the problem. Apparently this is a known issue with the 12 speed DI2 setup. I guess I can do a warranty call with the LBS, but it's not exactly easy for me to get out that way. I might ride it around for a while see if maybe whatever is lodged in the chain manages to dislodge itself. Nothing on the gear itself appears to be bent or chipped, at least visually.
I've never owned a bike where that was an issue - even triple crank mountain bikes. My SRAM 10 speed cassette is perfectly happy riding around big ring on big ring and I've consistently gotten about 6,000 miles out of a chain since I had the bike. But whatever the issue is, it isn't a cross chaining issue, as the noise is happening when the chain is in the small front ring as well.
Just a guess, but a 12 speed is a pretty narrow chain and it covers a lot of cassette. I'd suspect a rear derailleur alignment issue rather than the chain. Can you look at it along the chainline from the rear and see if it's lined up when it's in those cogs? Not sure how one adjusts the electronic shifters, but if it was a cable shifter, I'd be trying a quarter turn adjustment (e.g. very small).
No, It's either a rear chainring issue, or possibly a chain issue. I'm thinking chain because a deep cleaning improved the situation but did not solve it. Plus none of the big sprocket teeth look bent or chipped - at least visually. The electronic shifters don't go out of adjustment and everything is working fine in all gears except the big rear, which is... really big. As far as a bent hanger, the bike has never been dropped or anything banged against the derailleur and it visually looks straight.
Di2 12 speed adjustment https://bettershifting.com/installa...peed-di2-rear-derailleur-shifting-and-limits/ Seems like a well written guide. Lots of comments that might include your specific issue. When I was mentioning aligned, I was referring to the chainline when viewed from the rear in the cog with the issue. Not suspecting a bent hangar on a new bike. What exactly does the noise sound like and can you replicate it when the bike is in a workstand?
I wasn't ignoring your suggestion, we have just had such a long stretch of crappy weather I didn't have the opportunity to get out in the sunlight and look close at things. It makes sense. Noise in the big ring only (or small ring only) could well be a limit screw issue. Anyway, so to get it to shift to the big ring I needed to pull it out and ride it on the street. I shifted it in to the big ring. And guess what? Smooth as buttah. I think whatever chain obstruction or whatever it was worked itself out. I rode it around for a bit, and no noise whatsoever. Maybe the solvents did their thing over an extended down period. I'm happy.
Update: Okay I was wrong. I'm not sure why it worked fine on a short test ride the other day, maybe I failed to actually shift in to the big gear. I got on it to do a real ride, tested the big gear out and clankity clank. It ended up being a limit screw issue. I studied the adjustment procedure and in the end, the limit screws are conventional and not some Martian alien technology, so a quarter turn later and I was good to go.
