Originally Posted by
ItsJustMe
My bike came with slime-filled tires. They've never been able to stop a leak from even the tiniest pinholes. I've never had slime in my valves since I was careful to pump with the valve up top, but I threw the tubes away. All the slime ever did for me was to leak out where the hole was and make a huge mess that I had to clean up and made it difficult to patch the tire. It did make it easy to FIND the hole, I guess.
In stark contrast I have used slime for years. It has saved me more times than I can count. It has plugged up literally thousands of goat head holes, holes from glass, holes from those thin wires from car tires, etc.
Only twice has it failed me. Once, a giant nail punctured my tire, I did not even see it. The hole was too large for the slime to keep plugged. It would plug for awhile, then spray slime everywhere, then plug up again. I managed to get to class on time, but everything was a mess, including my backback. Another time something slashed my tire, I have no idea what, and I had an instaflat that nothing would fix, not even a patch. I didn't have an extra tube either, so it sucked, but it wasn't the slime's fault.
I think the one messy time was worth it for all the times it saved me from changing a tube in over 9000 miles of riding.
To the OP, as others have stated, inflate it with the valve stem towards the sky.