[Closed] Is this a crack?

Doesn’t look like a crack to me, looks more like a gouge from a mating part. It’s both perfectly circular in form and there’s some signs of material being pushed out of the gouge if you look closely.
Having did that it’s hard to be sure from a photo.

Re ruling out the seatpost due to it happening when standing up - that doesn’t necessarily rule it out as the frame will tend to “twist” when pushing hard on the pedals, which can lead to relative movement of the seatpost hence noise.

To be totally sure of the seatpost id try removing it completely then doing a short ride to see if the noise is still there.

drip a small amount light oil/wd 40 on it an see what happens

Doesn’t look like a crack to me either - a more obvious give-away is the sign of movement like cracking. The witness marks looks like the edge of a threaded metal bush insert. However, the face of the shock mount does suggest there is some fretting - maybe some side to side? I’d expect to see some sort of bush or washer to protect the carbon otherwise it will erode in time.

I'd be sending off a warranty claim regardless. there's a possibility that its a failure between the capture thread and the carbon layup.
have seen a couple of similar failures where the captive thread just spins in the frame when trying to remove the pivot bolt (not santacruz examples). Also see Raceface carbon cranks which would be the same failure mode.
You could also put the shock mount bolt in from the other side and wiggle it about like a short lever. You'll soon see movement at the thread>carbon if there is any

Does the click happen if you ride with no hands?

How about riding one footed on either side?

I had a clicking/cracking noise recently in exactly the circumstances you describe. I re-lubed the BB, replaced the chain ring bolts (lubing them too) removed, lubed and reinstalled the Cinch spider. all torqued to the correct values - the noise was still there.

The pedals weren't tight enough. I lubed them and installed them to the correct torque (the first time I've ever installed pedals with a torque wrench) and the noise is gone.

Thanks for the tips everyone, some good ideas/things to look into.

drip a small amount light oil/wd 40 on it an see what happens

Am I looking to see if this is absorbed into the crack?

there’s a possibility that its a failure between the capture thread and the carbon layup.

This was my worry, I'll try the bolt screwed into it that you suggested and see if theres any movement.

Does the click happen if you ride with no hands?

How about riding one footed on either side?

One footed yes, and it happens more/louder with the right/drive side foot.

The pedals weren’t tight enough. I lubed them and installed them to the correct torque (the first time I’ve ever installed pedals with a torque wrench) and the noise is gone.

I've got some old pedals I could throw on to completely rule this out. I have also never used a torque wrench on pedals but I will this time!

I've had a persistent creaking going on with my road bike which I was 110% convinced was coming from the BB / chainset.

After an extensive process of elimination I tracked the source down to loose rear mech hanger bolts and the rear QR which need a bit of grease!

I’ve re-greased the lower link and torqued to factory settings

I would check, clean and regrease the other frame bearings / collets / bolts if you haven't already.. that used to sort out creaks on my V1 HT.

After an extensive process of elimination I tracked the source down to loose rear mech hanger bolts and the rear QR which need a bit of grease!

Mech hanger has been re-torqued but not greased. Will try that.

I would check, clean and regrease the other frame bearings / collets / bolts if you haven’t already.. that used to sort out creaks on my V1 HT.

Upper link also re-torqued, haven't fully removed and re-greased though.

Don't discount the seatpost as per my post above until you've tried with it actually removed !

My old Yeti SB66 had marks like that, was dismissed as bond lines between the insert and carbon lay up, which in reality didn't matter as there was about 6 cracks elsewhere on the frame. 🙂

That is not a crack.

Problem with creaks is they are never usually coming from where you think. Seat, seat post and pedal threads were the last few I had that sounded like BB.

If you tap it lightly with a hammer and work your way round you should be able to hear the dings change if it's a crack, not sure how audible attached to carbon though.

Upper link was always the source of creaks on my Ltc Hightower.
Remove the link clean and re grease always sorted it.

https://youtube.com/shorts/740ba-GLmFo?feature=share

This is it, must have been like this since new, so what am I supposed to do? Spacers to tighten it up? Anyone got a hightower who can check how much play there is?

There shouldn't be any play.
New shock hardware.
Easy to sort.

I'm guessing I'll need to measure it as it's not going to be the standard 20mm spacing. Unless it's the mounting hardware that's out of tolerance

Just measure the frame and shock then order to correct hardware.

https://www.tftuned.com/tech-help/71-mount-kits-and-bushings-for-rear-shocks

to me it looks like the shock is moving on the mounting hardware and pushing the spacers, rather than the mounting hardware moving in the frame.

is it easy to remove the mounting hardware from the shock? if it is, it is time to replace it.

Had a creak on my Santa Cruz, did all that you described to try and cure without success. Turned out it was the headset bearings, replaced and noise gone