I just was looking at a couple of rides I did several years ago. On one, 115 miles and 7000', I averaged 17.2. On my best RAMROD, 154 miles and 10,000', I averaged 16.2. When I was a little younger and in good shape, my buddies and I would average 18 on courses of say 60 miles and 3000'. We once averaged 20 over a hilly 80 miles, but that was an outlier. Never did it again. These rides were in my late 50s and early 60s.