What type of headset is it? In one of the uploaded pictures I can see the bearing dimensions (40 x 51.8 x 8, 45/36).
Is it FSA or Deda DCR compatible? I'd like to run a two-piece cockpit, for example Deda Vinci DCR, with a slammed stem (or only with a minimal height adapter), as the stack of the size S frame is rather high.
What is the rear tire clearance with GRX Di2? It was asked before, but I can't see a reply. My goal would be to fit a 50mm tire. My current bike has 420mm chainstays, 74 deg seat tube, and there is 4-5mm of clearance left to the GRX Di2 FD with a 50mm Schwalbe G-ONE RX on 25mm IW rim (measures 49mm). So perhaps with the 425 mm chainstays of the GRT this could fit? Any thoughts on this?