Help me identify what's causing the tink

[EB]

Originally Posted by NHAero

You folks are really a symphony of knowledge and experience!
This is a thru axle bike. I'm about to go out with a different rear wheel and see if the click/tink remains.

Is the thru axle torqued to spec?

[JedB]

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?

Based on the part in bold, I'm guessing there's just enough cross chain difference that when force is applied on the downstroke it "tinks" the front deraileuer.

[NHAero]

More data:
Different wheel, same model of cassette (11-34 11s Ultegra). Windy gusty day so my hearing maybe isn't as sharp. It took >8 miles but the tink is still there. It's significantly more intermittent. Once I was sure it was back, I stopped and tightened the seatpost clamp and the Thomson seatpost bolts. I really don't think this is a cockpit sound.

Next is put the original wheel back on (I'll pull the cassette and grease the freehub grooves again, and make sure it's tightened to spec). Then I'll pull the cranks and BB and install the new Praxis Zayante items. That will also give me a chance to re-do the chainring bolts.

[benb]

Does this happen on the workstand or only when you're riding?

I have had slightly loose spokes before mostly on MTB and they'll tink only when climbing in really low gears.. seemingly cause that gearing puts more torque through the wheels? It also seemed like lower tire pressures brought this out. It's a tink that I always found hard to isolate whether it was up at the cranks or in the wheel since you can't get it to happen when coasting.

Also does it happen in both rings or only one, I didn't see that. The problem I mentioned only happens in a small enough ring. Doesn't have to be the smallest ring but the gearing needs to be pretty low, down near 1:1.

[Tz779]

Originally Posted by NHAero

More data:
Different wheel, same model of cassette (11-34 11s Ultegra). Windy gusty day so my hearing maybe isn't as sharp. It took >8 miles but the tink is still there. It's significantly more intermittent. Once I was sure it was back, I stopped and tightened the seatpost clamp and the Thomson seatpost bolts. I really don't think this is a cockpit sound.

Next is put the original wheel back on (I'll pull the cassette and grease the freehub grooves again, and make sure it's tightened to spec). Then I'll pull the cranks and BB and install the new Praxis Zayante items. That will also give me a chance to re-do the chainring bolts.

dang! ok, my thought was a pawl in freehub but that isnt it!

[Mark McM]

Originally Posted by benb

Does this happen on the workstand or only when you're riding?

I have had slightly loose spokes before mostly on MTB and they'll tink only when climbing in really low gears.. seemingly cause that gearing puts more torque through the wheels? It also seemed like lower tire pressures brought this out. It's a tink that I always found hard to isolate whether it was up at the cranks or in the wheel since you can't get it to happen when coasting.

Also does it happen in both rings or only one, I didn't see that. The problem I mentioned only happens in a small enough ring. Doesn't have to be the smallest ring but the gearing needs to be pretty low, down near 1:1.

I have also experienced this. As the wheel rolls, the spokes at the bottom of the wheel (in the so-called "Load Affected Zone", or LAZ) will lose tension, and then regain tesion as they rotate out of the LAZ. If a spoke is under-tensioned, it can completely slacken and its nipple can momentarily shift or loose contact with the rim hole in the LAZ, and make a "tick" sound as teh spoke leaves the LAZ and the nipple slaps back into place when tension is regained.

Leaning the bike to the side, as we often do when riding out of the saddle, can also change the amount of tension lost in the LAZ, so a spoke may make a "tick" sound when rotating out of the LAZ when the bike is leaned in one direction, and be silent when the bike is leaned in the other direction.

We tend to lean the bike to the left when we stomp on the right pedal, and this will de-tension the left spokes more than when the bike is upright. The left rear spokes are already under low tension, so leaning the bike to the left might be enough to make a left spoke make a "tick".

This tendency for spoke tensions on one side to decrease more when leaning the bike should happen whether we are pedaling or not. So one test is to lean the bike under the rider when coasting or lightly pedaling, and see if the "tick" only occurs when the bike is leaned in one direction, and not the other.

[benb]

Originally Posted by Mark McM

I have also experienced this. As the wheel rolls, the spokes at the bottom of the wheel (in the so-called "Load Affected Zone", or LAZ) will lose tension, and then regain tesion as they rotate out of the LAZ. If a spoke is under-tensioned, it can completely slacken and its nipple can momentarily shift or loose contact with the rim hole in the LAZ, and make a "tick" sound as teh spoke leaves the LAZ and the nipple slaps back into place when tension is regained.

Leaning the bike to the side, as we often do when riding out of the saddle, can also change the amount of tension lost in the LAZ, so a spoke may make a "tick" sound when rotating out of the LAZ when the bike is leaned in one direction, and be silent when the bike is leaned in the other direction.

We tend to lean the bike to the left when we stomp on the right pedal, and this will de-tension the left spokes more than when the bike is upright. The left rear spokes are already under low tension, so leaning the bike to the left might be enough to make a left spoke make a "tick".

This tendency for spoke tensions on one side to decrease more when leaning the bike should happen whether we are pedaling or not. So one test is to lean the bike under the rider when coasting or lightly pedaling, and see if the "tick" only occurs when the bike is leaned in one direction, and not the other.

I'm going to speculate the way I have heard this related to pedaling uphill in low gears meant I had a drive side spoke de-tensioning in that condition where it got just the right amount of lean + the extra torque applied from being in a really low gear.

I suppose I'd have to see a video of myself but at these low speeds uphill on MTB I don't think I'm leaning the bike a whole lot. For me that's more of a road thing at a much higher power output. I'm talking about stuff like a 25%+ grade off road where you are barely able to keep traction as you climb it so stomping really hard on the pedals doesn't work.

[NHAero]

Originally Posted by benb

I'm going to speculate the way I have heard this related to pedaling uphill in low gears meant I had a drive side spoke de-tensioning in that condition where it got just the right amount of lean + the extra torque applied from being in a really low gear.

I suppose I'd have to see a video of myself but at these low speeds uphill on MTB I don't think I'm leaning the bike a whole lot. For me that's more of a road thing at a much higher power output. I'm talking about stuff like a 25%+ grade off road where you are barely able to keep traction as you climb it so stomping really hard on the pedals doesn't work.

What I think I am hearing is that the tink disappears under heavy power and is most noticeable under JRA conditions.

[m_sasso]

Is your chain line spot on when you are in the middle cog of your cassette? Sounds like you may be getting a release of binding tension between your chain and rear derailleur pulley wheels. Have you had your rear derailleur apart? Are the pulley wheels in the correct position and orientation? Is your B tension adjusted corectly?

[thwart]

Originally Posted by NHAero

The imperfect teeth as a cause seems plausible in the sense that chain angle could affect whether a burr or similar would make noise. What mitigates against this is that this crankset was on another bike previously without this issue.

I should have said that this is the bike that had the twisted portion of the chain that I straightened. Again, if the periodicity matched one chain rotation instead of one crank rotation I'd be more suspicious of the chain as a cause.

Even so, this seems to be a possibility. Changing out the chain would be worth a try.

[NHAero]

Originally Posted by m_sasso

Is your chain line spot on when you are in the middle cog of your cassette? Sounds like you may be getting a release of binding tension between your chain and rear derailleur pulley wheels. Have you had your rear derailleur apart? Are the pulley wheels in the correct position and orientation? Is your B tension adjusted corectly?

RD is not very old, so haven't had it apart. I think B screw is properly adjusted, and chainline is good.

[NHAero]

Originally Posted by thwart

Even so, this seems to be a possibility. Changing out the chain would be worth a try.

I may try this if the new cranks/BB doesn't solve things.

New crank seems to mean i need to re-do the R8000 FD set-up, so no time for a test ride today :-(

[unterhausen]

I wish I could find the click on my mountain bike.

A "tink" may be some construction debris stuck inside a tube. I was just handling a top tube with a internal guide tube, and there was a tink. I decided I better get rid of it, and eventually I found out it was the burr from a rotary tool bit stuck in the internal tube. I really don't remember breaking it off. Of course, that would have been obvious when I tried to put housing through the tube. There is only so much opportunity for such things on a lugged bike, but TIG'd frames have all sorts of hidey holes

[rsl]

Originally Posted by NHAero

More data:
Different wheel, same model of cassette (11-34 11s Ultegra). Windy gusty day so my hearing maybe isn't as sharp. It took >8 miles but the tink is still there. It's significantly more intermittent. Once I was sure it was back, I stopped and tightened the seatpost clamp and the Thomson seatpost bolts. I really don't think this is a cockpit sound.

Next is put the original wheel back on (I'll pull the cassette and grease the freehub grooves again, and make sure it's tightened to spec). Then I'll pull the cranks and BB and install the new Praxis Zayante items. That will also give me a chance to re-do the chainring bolts.

Based on this info my idea probably isn't relevant. But bike noises are maddening so I thought I'd share for the good of the order for anyone dealing with creaks/thunks/tinks (sorry if this is a threat hijack!). I had a mystery sound that persisted after I tried multiple solutions including buying and installing a Wheels Mfg. bottom bracket, and many of the other solutions offered here. The fix was to have my LBS mechanic repress the cartridge bearings in the hub. Credit to Steve Garro for suggesting the solution.

[jasonification]

Sorry I didn't read through all the responses, but I had a "tink" with my bike a while ago..turns out it was the front derailleur cable getting pushed around by my shoes/pedal..