Originally Posted by
ChinookTx
Do you have a pump that screws on the valve? Some tubes have a removable valve that may get loosened when you remove the pump. Maybe it was borderline and hitting the bump pushed it over the edge. I'd be curious to see if it holds air when you mount it with a tire and pump it up to full pressure.
I ran into that with a batch of Conti tubes. They were just loose enough that they were fine until you unscrewed CO2 during a ride. Not obvious.