Tried riding with my seat 2 inches lower for a week and my knees quit hurting
I kept getting this dull ache in my right knee after my 6 mile ride to work, so a guy at my local shop in Sacramento told me to drop my saddle about 2 inches lower than what felt right. I thought he was messing with me because everyone says raise it, but I tried it for 5 days straight. My knee pain went away by day 3, though my quads felt way more tired on the hills. Turns out I was overextending at the bottom of the pedal stroke and never noticed it. Now I'm slowly raising it back up a quarter inch at a time to find the sweet spot. Has anyone else had knee pain fix itself from going lower instead of higher?
Two inches is a huge change, not a small tweak. That is not "fit tuning," that is basically turning your bike into a different bike. Dropping your saddle that far mostly just makes your knee bend more at the top of the stroke, which changes the angle and can mask pain. It does not prove you were overextending, it just proves you moved the problem somewhere else.
Your quads getting wrecked on hills is your body telling you the new spot is not right either. Six miles is also a pretty short ride, so a week is not much of a test. Five days and the pain "went away by day 3" could just be your knee calming down from whatever you were doing before.
People love to turn one good week into a rule for everyone. There is no rule here. Get a real fit done by someone who watches you pedal, not a guy at the shop eyeballing it and telling you to slam your seat down two inches.