Hi,

All the above posts are very informative, starting with Bill Kapaun's. All tell me what I have to be mindful of. Thanks.

To answer a few questions:
I am a fairly heavy rider because I often carry my son on the back. Altogether, we weight 250+ lbs. That weight is why I worried about the "right tube pressure" in the first place.
The wheels, I believe, date from the 80's and are probably steel. (The frame is chromoly, but I haven't checked for the wheels.)

I'll get a new tube tomorrow and install it. Thanks again for all the tips.