Originally Posted by genejockey

I learned a valuable lesson today: Make sure the valve stem on your spare tube is long enough for all the rims on all your bikes. Remember those Fulcrum wheels I was bragging about fixing the bearing preload on? Turns out the rims are surprisingly deep. Deep enough that the little stub of the valve stem that pokes out is NOT long enough for a Zefal hpx pump head to grab. I figured this out after pulling the punctured tube out, inserting the spare, and getting the tire back on the rim. Then I couldn't pump it up. I tried for a good 5 minutes before giving up.

So, back to the punctured tube. I also carry an instant patch kit, so I pumped up the old tube and searched for the leak. But it's a slow leak and I was outside on a breezy day. So after a fruitless few minutes trying to find a hole, I switched to looking for the cut in the tread, which was tough because as it turned out, it was very small, not very deep, and ran parallel to the tread. I found it. It was near the valve. I STILL couldn't find the leak, so I put one instant patch on each side of the valve, where I the hole seemed likely to be. I pumped the tube up a bit and it seemed to be holding air better, so I swapped the patched tube back in, replacing the useless spare.

It was then that I discovered that a 30+ year old Zefal hpx can be finicky. Some strokes of the pump did nothing at all. In the end, I had to hold the pump very steady at exactly the right angle. I eventually managed to get the tire pumped up to something like the right pressure. I set off for home, which was 5 miles away.

2 1/2 miles later, at a stop sign, I felt the tire and it felt a bit soft, so I decided to pump it up some more. In the process of trying to get set up to do that, I blew out most of the air that was left in it, and had to pump it up from almost empty again.

I made it home, riding gently. The whole flat fixing adventure took nearly 1/2 hour!