I have two types of motivation. One motivation to plan the rides, to get into the sport, etc. The other is during the ride.

During the ride is easy my motivation is to complete my goal. To finish the ride. I may not finish as fast as I want but I will finish. I may have to chant or run a song though my head on repeat but I will finish.

That is why I mostly focus on distance and difficulty. I am not good at speed goals.

The other hand is the planning and getting into it part. My motivation there is more complex. To do a sport well I have to make it my primary non-work focus. This is the only way I get excercise as I am bad at going to gyms as I can't focus. So I plan trips, I plot routes, I build elevation profiles with my GPS. I then start logging everything in a book. Basically I go a little nuts getting into a sport for real. But all this focus is what gets me on the road planning rides I can do and enjoy. Cycling is replacing rock climbing for me as I have lost my partner (to a woman in Bend).

In that regard cycling is working great I have already lost two pounds by focusing on cycling. It is easier for me to ride 150 miles a week than to get to the climbing gym 4 times a week.
-Duncan