How so? What's your view?

I'm sorry, but 30 degrees at the bottom of the pedal stroke? There must be an error there -- it is impossible for the knee to have that angle in that position.

When Machka and I were measured on taking delivery of our tandem, the angle was measured down the femur, through the knee and down the tibia. As far as I know, this is the way all knee measurements in fit are taken.

I recently lowered my saddle while on a ride and it felt way too low at first, so I brought it back up 1 or 2 cms. It still felt low after being so high but I've gotten used to it and it feels good.

I had been experimenting with saddle height over the past month and found the answer to the question "how high is too high?" I began to experience all sorts of sit-bone and hamstring pain while riding, which convinced me to drop the saddle.

With a comfortable 52 mile ride this weekend, I decided to record all my measurements using the Park Tool "Road Positioning Chart" as a guide. They measure saddle height from the center of the crankset, straight up to a line extended from the top of the saddle (I used a board resting on my (level) saddle and measured up to the bottom of the board). I measured out at 785mm. I'm 6'3" with standard proportions (32 inch inseam). I actually think I could go up a centimeter or two.

I subscribe to the trial-and-error method of bike fit but now that I've got things dialed-in again, I've got everything recorded so that when I decide to play around again with my fit, I can better track my changes.

Everyone is different. If your saddle feels good at that height and you get the power you want and don't experience any pain, then that's where it belongs.

When you drop your seat, it's normal to feel that you've lost some power. Check out CDR's blog post about early season adjustments to saddle height.

I have a very similar inseam and run approx 900mm saddle height. Knee angles are all in the "normal" range.

It always seems to me like anything based on averages (e.g., the 0.883 thing) is always going to be more unlikely at either end of the bell curve (in this case for height).

30 degrees is the correct number. It refers to the degree of bend at the knee, not the angle formed when the knee is bent. 0 would be the angle with the leg straight.

Technically, a 30 degree bend would create a roughly 150 degree angle at the back of the knee.

Why measure? Why not establish a way to go by feel? Try placing your seat in extreme places, like all the way forward, all the way back, or drop the seatpost by half, and document what effect it has on your muscles.... mainly which ones fatigue faster than normal.

As an example... if you are too far forward, the frontal center of your quadriceps might fatigue very quickly as the angle that you try and apply power to the pedal as you come over the top of your stroke is too compressed. As you begin moving the seat back you'll see that fatigue becomes less and less.... until that frontal center quadricep is no longer the one fatiguing pre-maturely.

Link?

What bike (and size) do you ride and do you need a 350mm post?