I used the seat-of-your-pants method for years. It is OK for recreational riding, but you can still make a lot of improvements. I did a fitting with a university cycling team coach. He used lots of rulers and protractors and levels and studied my cycling motion on a trainer and on the road. He moved my saddle up and forward by several MM and also adjusted my cleats and handlebar height. The new riding position is even more comfortable, and also more powerful.jason_haza said:Best way is to just go riding, with an allen wrench and adjust the thing over a few miles' ride. Preferably a bike only spot that you can stop often on....Your lower back, legs and ass will tell you way more than a ruler how the seat should feel.
Here's what the specialized user manual says: "The saddle is at the correct height for you when, while seated on the saddle and with the crank arms parallel to the seat tube, you can just reach the 'down' pedal with one heel." This was also the method my LBS used. The geometry of the sitting position on the bike is such that if the above instruction is followed, there will inevitable be a slight bend in the knee when the pedal is at its lowest position (6 o'clock).jg150 said:My understanding is slightly different, or at least the way I first set my seat height was done this way per the instructions that came with my bike...
shoes off, sitting on bike in the riding position (helps if you have someone hold the bike up for you or use a trainer), place the heal of your foot on the pedal at it's lowest point of rotation. Your leg should be completely extended when in this position.
As you ride you will make some minor adjustments to get it dialed in, so this should just be your starting point.