Thursday was one of those days...
I spent Thursday afternoon eagerly anticipating a ride on the Q507 after work. Arrived home to find the front tire flat as a pancake. I'd pinched the tube when I put the tire on (without the help of tire levers, even!), and the spare tubes I'd ordered hadn't arrived yet.
OK, I thought, I'll just hop on the Silvio for now, patch the 507 tube later, and try again tomorrow. Began unscrewing the valve on the front tire of the Silvio to check the pressure...and the top of the valve core fell off in my hand.
I put a cap on the valve and rode anyway.
Dug out a new patch kit that evening, patched and reinstalled the tube, let it sit for an hour, checked it...dead flat. Only half the patch had adhered. Ripped it off, tried a new patch--and once again, totally flat in an hour. One little channel, maybe 2mm wide, hadn't sealed. Glued another patch half over the first one to cover the gap. That stopped the leak, but the third patch also had one small place that wouldn't stick. Either I'm really bad at this, or the patch kit is defective, or both.