canklecat

Check the easy stuff first.

Start with the spokes. Pinch them where they cross. If you hear any squeaking, there's the likely culprit. If you feel any unusual friction or grit, that may translate to squeaking under load when pedaling hard.

I chased down a persistent squeak last year that most occurred on climbs or standing to pedal. Ended up rebuilding the BB, hubs, checking the cassette several times, etc.

Nope. It was the rear spokes. First time I've had wheels with black finish spokes and they were squeaking. I tried oil and grease but what worked best was leftover scented candle wax. There's usually a little left in the jar after the wick burns out. Scented candle wax is soft enough to scrape off with a fingertip or fingernail. I just moosh it between the spoke crossings. Lasts about a month before the squeaking starts again.

I had a similar issue with another wheelset, a low priced Wheelmaster for my errand bike. For the first month the spokes would occasionally ping under load or when climbing. Settled down after a month so nothing else was needed. Those were heavy gauge plain aluminum or steel (hard to tell, small magnets don't stick to some steel). No persistent squeaks after a brief break-in period.