In the last few weeks, my front wheel developed an intermittent leak at the valve; sometimes slow, sometimes catastrophically fast.

The mind-boggling part was that dipping the wheel in a water tub at \~30 psi showed zero bubbles. Yet, pumped up to 50 psi, it would either hold fine or gush air directly out of the base of the tubeless valve stem. Wobbling the valve made the leak worse, so I assumed a loose or damaged valve seal. I replaced the stem seal and tightened the locknut on the rim, but the issue persisted.

Begrudgingly, I decided to replace the factory tubeless tape, since that's what Reddit seems to preach for valve leaks. I wasn't convinced as it made no sense to me how a tape failure elsewhere would only leak around the valve and not through any of the spoke holes.

Much to my surprise, peeling off the factory tape revealed sealant pooled inside the rim cavity. It dawned on me that the tape had failed, pressurising the entire double-wall rim, and the only thing holding that air in was the outer valve locknut and its tiny O-ring.

I don't know what's wilder: that the spoke nipples didn't blow bubbles first, or that a finger-tight valve locknut managed to hold 50 psi.

Replaced the tape, and the problem was solved. Trust the tape advice!

It was the tape!