On Friday, July 3, 2020 at 9:15:34 PM UTC+2, wrote:
Remembering that I am 6'4" tall. The bike weights are somewhat informative.

1. 2018 Emonda with Aero carbon wheels and Ultegra Di2 60 cm Saddle flat repair kit and full large water bottle full. 21.28 lbs.

1998 Basso Loto no bottle, pedals or saddle pack Campy 10 speed and Fulcrum aluminum wheels. 62 cm 20.78 lbs.

2006 (??) Lemond Zurich 58cm no water bottle or pack Campy 10 speed. 55 mm aero carbon wheels, Look Delta pedals Reynolds oversize 853 tubes 19.78 lbs

2012 Trek Madone 60 cm with manual DuraAce 11 speed saddle pack, half filled large water bottle. Pro-lite 40 mm aluminum wheels 20.17 lbs. There is something drastically wrong with the manual group and I am forced to take it into the shop. It acts as if there is something wrong with the chain with it hopping on the rear derailleur idle pulleys every couple of links. New chain, freshly waxed, Every thing possible done to align front and rear derailleurs. Ultegra 11 speed chain but it acts as if it was a 10 speed chain. Could the chain have come from Shimano with a twist in it? Sounds unlikely but that's the way it acts.

You comparing bike weights leaving the water bottles on the bike, some filled, some half filled or no water bottle at all or a saddle bag or not? Weird.
You know that a 11 speed Ultegra chain has a mounting direction?

Lou