Both sides of folio 132 and 133. The graffiti proves
that both were originally one sheet. The fortress sketch on the front side of folio 133 just blocks the center of the bicycle in translucent view. Exact there Pedretti's line sketch has the missing gap. It suggests he
really saw some of the bike but a part was blocked.
/ レオナルド・ダ・ヴィンチ