Rivnuts from Homestead, PA on 8/31/2022 4:56:06 PM:
Scout Dad:
You've raised a few questions about your proposed spring break bike trip from Pittsburgh to DC. I'll offer the following observations as I'm sure others will as well.
As for biking while standing, I don't believe that is an issue at all especially in the direction you are planning to ride assuming that both of the current detours off the towpath are finished by then. There are only a few hills that might require you to stand and some are just man-made overpasses. All are short enough to walk without losing much time.
As for training and stamina, I don't believe it is as much about how many miles you and boys can ride in a day but, rather, how many days in a row you can ride those miles. I would suggest more days of fewer miles if stamina concerns you.
Your point about the pumps at the hiker/biker camp sites along the C&O Towpath at that time of year is valid. However, with four people riding, you should be able to carry enough water among you to make it between towns where you can get water especially since you're not planning to ride in the heat of the summer.
Lastly, and you didn't ask the question, but the weather in April and especially in early April along the GAP can vary widely. It ranges from reasonably warm and pleasant to cold and miserable. Precipitation is variable as well and could easily if not expectedly include snow flurries. (There was more that 4 inches of snow near Meyersdale in mid-April this year requiring some riders to layover or seek shuttles due to the weather.) Frankly, I avoid doing that ride during April, preferring to wait until mid-May when the weather is better and more predictable.