This late spring and summer (1999) I have been getting out most evenings and burning up the miles. I recently bought a Cateye bicycle-computer. It has the usual odometer and speedometer. Also it has a cadence display which helps me maintain a high rpm on my pedaling. I try to pedal at 80-95 revolutions per minute. This makes for less torque to my knees and helps me maintain a higher speed. Recently I have been averaging 17 to 18 mph for up to 54 miles (~3 hours). Here are actual mile's pedaled for an eight week stretch in 1999.
In a 5 week stretch I racked up over 800 miles by myself. Over this
time I'd been pushing myself almost every evening in order to get
35 to 55 miles done per "sitting". At some point my left pedal crank broke
and I was reduced to my old bike while I get the crank replaced.
After taking a pause, I pulled back to 100-135 miles
a week so that I could free up some of my evenings for other activities.
But the whole experience has been interesting. Prior to this I never
had thought I was capable of sustaining this type of mileage for more than
a couple days. Now I know I could probably do this on nearly year round
basis (allowing for weather). Interestingly, with the mild weather the fall and early winter of 1999, I continued to put on miles on the weekend. My last pedal (45 miles)for the year was in the second half of December before the snow fell.