Hello;

I have been riding a nominal 54cm surly crosscheck, which has a 56cm top tube. I have 2 other roadbikes that are nominally 53cm size and they have around a 535ish mm top tube. When I'm in the drops on the 2 smaller frames I am bunched up much more tightly than when I am in the drops on the surly. I am about 5'8" (meaning less than that).

Where should my knees be in relation to my elbows as I bomb down hills in the drops pushing for a landspeed record? Even on the large surly I can pull my elbows in and my knees will just graze them as a pedal.