to fit my Trek 520 touring bike for cycling across US. My bike and me become one! It cost 3.5 cent per mile to ride 4232 miles comfortably. Btw, one friend told me that US routes have aggressive car drivers. I need to look into trans Canada, 4630 miles though.
The
fitting master/genius Les welch is very famous in the community and
referred to me via a semi professional cyclist. He can manually fit and
cost $100, but the computer aided simulator speeded up the process to
fit the most heathy and efficient settings of my biking, then he
adjusted my bike accordingly. Les made four major changes to the bike,
in addition to the tension of the seat. He also replaced the handlebar
post to make the handlebar closer to me so I can bike with the right
weight distribution. 
It
takes a lot of experience to come up the settings based on my body and
bike limitations. I bought my bike with a front rack at $800, about half
price of msrp, so I can invest in fitting to make me comfortable for
the long ride. The computer fitting costs 225-250 in DC, but I
persuaded the owner David to charge me $150, because he gave me the
price before the marathon/computer system and I was too busy to go, and
les happened to have an opening on that cool winter afternoon.
The link to Guru bike fitting system that provides an wide range of motion and real-time adjustment to create the perfect fit http://www.gurucycling.com/technology/#guru-tech-prompt1