Cranks with shorter arms. Used to use 175mm, now use 170mm and I might try a 165mm on a future build. The knee joints agree this was a great change, as they don't complain anymore after a long ride.

Shorter Stems. compared to 1970s-1980s bikes, it seem mftrs have made the newer bikes with longer top tubes. I like a 60cm (seat tube) bike, but I need to change the stem from the typical 120mm to 90mm.

Handlebars. I actually like wider bars. Most newer bikes I've bought have come with 40cm-42cm bars, I've replaced them with 44cm bars. Feels soooo much better!

(I have a lot of 70s-80s bikes, and a few from 2000 - 2008).