Except it doesn’t seem to be any of those. I’ve got a loud-ish clicking/pinging sound when pedalling seated on my hybrid. It’s worse on rougher ground (when it’s pretty much every time round 6 O clock on the drive side) and intermittent on smoother stuff. It disappears when I stand up, and occasionally it happens when I shift my weight on or off of the saddle without pedalling.
I’ve tried a different seatpost, saddle, and seat clamp in various combinations and cleaned and greased everything but it doesn’t make any difference. Also tried different pedals and QR skewers. Chainring bolts seem good and tight.
Any suggestions?

Tagging as I’m in the same predicament.

Throw a bucketof grease at your bike.

Same here, on several bikes.

My theory is the seat post has a slightly smaller diameter than the inside of the seat tube. It is pinched tight at the seat clamp. When lateral load come on from the saddle, it causes the bottom tip of the seat post to move towards the seat tube, creates a small rotation in the seat clamp area, causing a creak.

Solution a tighter fitting seat post, and lots of grease/anti seize.

Well that’s my theory.

Rear quick release?
Headset?
Suspension bushing?

Try a bolt through seat clamp if you have one. These can be done up tighter than quick release.

Also check the weld around the seatpost area. I had the same annoying issue and when I examined the weld and removed a bit of the powder coat I could see a small crack at stay to post tube interface.

Check everything…. And check again. Brake mounts, bb, chainring, pedal threads etc

I find I have this problem with every KCNC post I have.
A mechanic friend suggested roughing up the rails with emery and then regrets. Seems to have worked.

“emery and regrets”

That made me laugh 🙂