Need Wrenching Help - Noise in 34 tooth chainring

[tlarwa]

The set-up ... DA 7800 shifters, Ultegra 6600 RD, Ultegra 6700 (I think) FD, SRAM Red compact crankset with stock SRAM Red chainrings (50/34), Shimano 10-speed chain (not sure which model) and CS-6600 cassette (11-28). The drivetrain runs quiet in the big ring, through all the cogs (except when extreme cross-chaining, of course). The issue is in the small chainring ... I get a noise, similar to rubbing of the chain on the FD or the chain not sitting correctly on the teeth, when I'm in any cogs from about the middle of the range and up (let's say 15 or 17 tooth on up, but I dont remember exactly what the configuration is). The front derailleur cage is definitely not rubbing the chain, I've checked it multiple times on the workstand. And the trim adjustment is centering the FD correctly (and I use it). While it's not causing any problems, and the shifting seems to be okay, the rubbing noise is driving me mad. Any thoughts? Should I try a SRAM chain with the SRAM rings? Help!

TOm

[AgilisMerlin]

which chain is it.

ultegra, direction specific?

curious

chain length?

perfect in big ring eh.

how old is drivetrain. new problem on old setup, any replaced parts lately?

what shape are the pulleys in? smooth

so many questions :eek:

[tlarwa]

I'll have to check the chain, honestly don't remember. Didn't know they could be direction-specific, though. The only change was going from a Shimano R700 compact crankset to the SRAM. The RD is practically new, so no pulley issues. I'm thinking maybe an issue with the 34 ring? And no, it's not installed backwards (I checked to make sure;)).

which chain is it.

ultegra, direction specific?

curious

chain length?

perfect in big ring eh.

how old is drivetrain. new problem on old setup, any replaced parts lately?

what shape are the pulleys in? smooth

so many questions :eek:

[oldpotatoe]

The set-up ... DA 7800 shifters, Ultegra 6600 RD, Ultegra 6700 (I think) FD, SRAM Red compact crankset with stock SRAM Red chainrings (50/34), Shimano 10-speed chain (not sure which model) and CS-6600 cassette (11-28). The drivetrain runs quiet in the big ring, through all the cogs (except when extreme cross-chaining, of course). The issue is in the small chainring ... I get a noise, similar to rubbing of the chain on the FD or the chain not sitting correctly on the teeth, when I'm in any cogs from about the middle of the range and up (let's say 15 or 17 tooth on up, but I dont remember exactly what the configuration is). The front derailleur cage is definitely not rubbing the chain, I've checked it multiple times on the workstand. And the trim adjustment is centering the FD correctly (and I use it). While it's not causing any problems, and the shifting seems to be okay, the rubbing noise is driving me mad. Any thoughts? Should I try a SRAM chain with the SRAM rings? Help!

TOm

Worn out small ring?