In my experience the quickest way to get faster is to ride with guys, girls that are faster.
Fitness and machinery etc aside I have found you will get faster quicker doing this rather than riding on your own.You tend to push yourself a bit harder and for longer than by yourself and all of a sudden its not an effort as much, you've just picked up your average.
yup, spot on.
I have also found that as I get older, even when my fitness is up, that I dont have the 'punch' or anywhere near the acceleration I did when younger. Not that I had much to start with but I just have less now
again, quite right. But these days I have strength and stamina that I didnt have as a youth, and I'm doing less miles. After 60 miles I can grind the young bucks into the ground and drive into headwinds. I could never do this in my racing days.
A bicycle can't stand up on its own as it's two tyred