Fixing a flat

On Friday, I jumped on my bicycle to ride back to my apartment after frisbee and discovered I had a very flat tire. Fortunately, the frisbee field was only a short 7-min walk from home. Yesterday, I consulted the internet (here, here, and here, complete instructions and even photos), and after a call to my resident bike expert, Robin, decided to dive into the task myself. I struggled briefly to unscrew the back tire from the bike frame, but it basically came off by itself after I unhooked it from the gear mechanism. I had a greater struggle to get the tire off the wheel rim, not knowing how the tire really fit onto the rim (part of the time I found myself pulling the inner-tube off the rim, not just the tire). But after about 10 mins, it too was off. Robin suggested putting the inner-tube in water and finding the hole by looking for the bubbles (good suggestion!). I found the hole, more like a tear, but was unable to find anything suspicious protruding from the tire (after gently running my fingers along inside & outside). I put in the new inner-tube before church this morning, and reattached the back tire to the frame. I'll add some air this afternoon. Hopefully whatever poked into my inner-tube has since left my tire ... otherwise this will be a brief ride!