Seat Height, Reach and Posture for Healthy, Comfortable Riding
Simply getting saddle height can seem like a tedious redundant process when there are so many methods currently being considered as useful and most concise. There's the heel method, the 109% method, Lemond method and of course the Holmes method. It uses a device called a goniometer for measuring the angle of the knee joint at the bottom of the pedal stroke. Holmes recommends an angle of between 25 and 35 degrees and closer to 25 for those with a history of patella tendonitis. My right knee has been through a lot over the years and have found having a slight bend to the knee while on the saddle with pedal on down stroke is a good starting point.
My right knee has seen it's share of injuries over the past thirty years and I have found that fore and aft position of the saddle is just as important as saddle height in eliminating knee pain. Using a plumb bob is a simple method after seat height has been established. Image at left shows pedals in parallel position to one another, then using what is called a plumb bob or a string with weight on end to establish a vertical line as a reference. As a starting point observe the vertical line from tip of knee cap aligning with center of pedal axle. (Note: Use of clipless shoes adds the consideration of cleat adjustment and float). Then see how it feels after a couple weeks of riding and make corrections as feels appropriate and consult your trusted LBS.
Having basic guidelines for bike fit can help a person get situated so as to dial in and and fine tune other aspects such as multiple hand positions and the types of handlebars and accessories that can be implemented for improved comfort and handling as well as having room for other accessories such as lights and a computer for mileage, speed, etc. Know this, the two most common complaints of bike riding discomfort are hand pain or numbness, butt and or lower back pain.
Often times I find bikes sold as touring bikes are not geared properly for most touring or recreational commuter needs. Having more of a mountain bike gear ratio and drive train is a necessity for folks wanting to be able to climb reasonably steep hills and carry packed panniers, either fully loaded for touring or grocery getters for commuting. A good service oriented LBS will explain options to get a bike to serve your needs, that's what they're there for. Point here is to shed light on the fact that having some knowledge of basic bike nomenclature and fit will be appreciated by your LBS when communicating during your search for that right bike for you. It's a fun and rewarding process to find that bike for oneself, as it should be and I didn't discuss wabi sabi or feng shui. Well, I'm not here to give perfect advice.
Other sources of information for this topic:
Bike Touring News
Bicycle Touring Pro