Originally Posted by
beng1
That is not all, wind is as or more a factor than terrain. Where I live up on the Great Lakes it is rare to have a ride with no wind, and the wind is always different day to day. I would have to ride the same loop dozens of times over a month or two to get a true average speed for the loop that includes variable wind. Last year I did ride one loop dozens of times over months and on a day with low wind that was near zero I could go 20mph average, but usually there would be 5mph to 10mph wind for half the loop, and often enough wind higher than that, so I would say the average over months was much lower than 20mph, maybe as low as 16mph.
On any race day it will be the same story. I can look at old race results usually they were never what I was capable of, they were what the wind and weather on that day allowed. Some time-trials I ran were so cold I had to wear heavy clothing, also a factor. Also riding with a large group of people makes you much faster because riding behind another rider takes half the power as riding in the front and breaking the air for everyone else behind you, so you can save all kinds of reserve power for most of a group ride or race compared to riding a TT where you are fighting the air the whole way.
So speed is fun, but not as much fun as just dong the race or ride and not worrying about your speed at all. You will never be able to predict your speed for any future ride or race in advance because of weather variables, and of course once you are an old man you get slower every year, maybe every few months. We have harsh winters here and everyone gets out of shape in the off-season. One of my interests is to see if I can go as fast this year as last on the same bikes over the same routes as I did last year when one of those rare low-wind days comes up. My guess is I am already slower, but I also care less than I did last year, and I am not planning on doing as much riding either, so again, I have zero idea what my average speed is going to be in a week, a month or in four or six months from now.