Originally Posted by
chasm54
the medium-term target for me would to go under the hour for 40km...The anaerobic stuff definitely needs a lot of work, though.
Anaerobic stuff is the most trainable in the shortest time period.
40k's are different beasts than 20k's. They require a lot more technical expertise and discipline. The penalty for a lack of either one of those is pretty big. If that's your goal I'd ride as many of them as you can, and draw out a 40k course you can practice on. I'd want to ride that 1/2 times a month; set marks at 10,20, and 30k and note the time you arrive at each point. Then go back and figure out where you can improve.
In 95% of the files I see people go out too hard.