Help me identify what's causing the tink

[NHAero]

My Habanero with SRAM Force 22 crankset with SRAM MTB spider and 44/28 chainrings, and 11-34 11s Ultegra cassette, has a tink sound that is periodic with crank rotation. It occurs roughly when the DS crank is passing the DT, and it only occurs in the larger cassette cogs (23-25-27-30). Statically I can't see anything hitting or rubbing; the FD is actually in the trimmed position and is not being hit by the crank; and I tried a set of pinned flat pedals with the same result to eliminate the pedals.The cranks feel tight without play in the BB, the chainrings appear tight on the spider and the spider tight on the crank.

Ideas please?

[AngryScientist]

Check the chain quick link.

[slowpoke]

If you wear shoes with laces, might be the plastic tip of the shoelace hitting the chainstay.

[NHAero]

Originally Posted by AngryScientist

Check the chain quick link.

I don't think that would be periodic with the crank rotation - do you see it differently?

[NHAero]

Originally Posted by slowpoke

If you wear shoes with laces, might be the plastic tip of the shoelace hitting the chainstay.

Absolutely this has been a culprit in the past! This bike uses shoes with Boas, no bits that hit the cranks.

[duff_duffy]

Have a spare wheel you can throw on? I’d bet rear cassette and chain interacting weird.

[SBash]

Originally Posted by NHAero

My Habanero with SRAM Force 22 crankset with SRAM MTB spider and 44/28 chainrings, and 11-34 11s Ultegra cassette, has a tink sound that is periodic with crank rotation. It occurs roughly when the DS crank is passing the DT, and it only occurs in the larger cassette cogs (23-25-27-30). Statically I can't see anything hitting or rubbing; the FD is actually in the trimmed position and is not being hit by the crank; and I tried a set of pinned flat pedals with the same result to eliminate the pedals.The cranks feel tight without play in the BB, the chainrings appear tight on the spider and the spider tight on the crank.

Ideas please?

Is the Cassette Lock Ring tight?

[NHAero]

Originally Posted by duff_duffy

Have a spare wheel you can throw on? I’d bet rear cassette and chain interacting weird.

I don't see how that generates a sound periodic with the crank rotation, but I think it is a good suggestion to try! Thanks
I just swapped another wheel in and will try tomorrow.

[NHAero]

Originally Posted by SBash

Is the Cassette Lock Ring tight?

Good question. I will check!

Edit: Yup, it's tight.

[tellyho]

Chainring bolts? Clean the BB spindle and BB cups? Look for a bent chainring tooth? Quick link interference? An obvious one, but long FD cable?

Nothing quite as maddening as a drivetrain noise you can't figure out.

[djg21]

Originally Posted by NHAero

My Habanero with SRAM Force 22 crankset with SRAM MTB spider and 44/28 chainrings, and 11-34 11s Ultegra cassette, has a tink sound that is periodic with crank rotation. It occurs roughly when the DS crank is passing the DT, and it only occurs in the larger cassette cogs (23-25-27-30). Statically I can't see anything hitting or rubbing; the FD is actually in the trimmed position and is not being hit by the crank; and I tried a set of pinned flat pedals with the same result to eliminate the pedals.The cranks feel tight without play in the BB, the chainrings appear tight on the spider and the spider tight on the crank.

Ideas please?

First, check that the chainring bolts are tightened. Then check to make sure the front derailleur clamp is tight enough. I went through this same process a handful of years ago on a Ti bike — every pedal stoke I got a click. The Shimano clamp that held the braze-on FD to the seat tube needed to be tightened; every pedal stroke, I’d flex the seat tube just enough to generate a click that seemed to resonate through the Ti frame and was making me nuts. It took me a while to figure it out.

[NHAero]

Originally Posted by djg21

First, check that the chainring bolts are tightened. Then check to make sure the front derailleur clamp is tight enough. I went through this same process a handful of years ago on a Ti bike — every pedal stoke I got a click. The Shimano clamp that held the braze-on FD to the seat tube needed to be tightened; every pedal stroke, I’d flex the seat tube just enough to generate a click that seemed to resonate through the Ti frame and was making me nuts. It took me a while to figure it out.

The bolts seem plenty tight and each of the two chainrings has its own set of bolts to the spider, and I get the click in the small ring too (which is pretty much not used here on MV, it's a 28T and I don't need it, but I tried it to see if i could isolate the sound to one chainring.) I gave the FD bolt a 1/8" additional turn but it also feels tight enough, and plus this Habanero Ti frame has a 45mm downtube and I don't think my piddly watts are flexing it much. I don't hear the tink when standing on the pedals but that could be my hearing too.

[NHAero]

Originally Posted by tellyho

Chainring bolts? Clean the BB spindle and BB cups? Look for a bent chainring tooth? Quick link interference? An obvious one, but long FD cable?

Nothing quite as maddening as a drivetrain noise you can't figure out.

Could always be the BB though this one is a Wheels Mfg thread together unit to adapt the SRAM crankset with a 30mm spindle to the BSA threaded BB.

Quick link wouldn't seem to be periodic with crank rotation.
Bent tooth is a good suggestion but I get the same sound on both rings.
Not the FD cable, this is a R8000 FD, and we learned recently in another thread here that they suck, but the cable excess exits to the rear

Thanks for the ideas!

[tellyho]

Oh, if you don't hear it standing: saddle rails, seatpost clamp, seatpost lube?

[Carbonita]

I fixed the same issue on Friday for a buddy after he'd taken it into his shop several times, and changed pedals. Anti seize and proper torque seat clamp and rails.