Always check the inside of the tire before putting a new tube in. I flatted yesterday, and put a brand new tube in that flatted less than two miles later. What happened?
The top of the presta valve stem came off and fell into the tire. Nice little point on the end of it.
I had THREE flats yesterday, but that's another story.
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2020 Giant Defy 2
Fuji Cross Pro
Scattante 650-R trainer bike
'06 Kona Jake the Snake