Originally Posted by u235

I just completed a 220 mile 3 day gravel trip with about 15 pounds of gear. After the first day of 90 miles my knees were killing me. Felt ok off the bike but any pressure on the down stroke sitting or standing and felt it on the front upper knee mostly. I was averaging close to 15 mph and did the first day 90 in a total of 7 hours including breaks. On day 2 and 3 I forced my pace down to about 12-14 and managed through the pain. At the end of the 3rd day (which was 80 miles and a +2000 ft climb) I was useless with no hope of going on. This was my first ever "long" ride. I've been riding 20-40 miles at a time 4-5 days a week for at least a year before this. I thought my bike is setup correctly but... I did tweak some after the first day like move the seat up and back a little to try to compensate.
Did I just try to do too much too fast and my body is not used to that? I wish I would have stayed at 10-11mph max which I easily had the schedule for.