zealot128: Nice, thanks. That looks similar as I measured from lightcarbon drawings
. 33c rim means 33mm internal width, what rim is that, what is a real width tyre measure?
Thanks for the update, i assume that the rim width is 33mm outside?
Can you take some pictures of the front derailleur with that setup?
Thank you very much, sir! But still, can I ask you to measure both the front and rear tire widths using that caliper, please? Or have you measured them and they really have 35mm width?
It seems the use of the Caracal Race 40C at the rear will be very difficult indeed. Anyway, I already have them, mounted on 21mm ID rims, and I'll teste it once the frame arrives. I also have some old 19mm ID wheels to test that tire at the rear. Or I can keep that
tire/rim at the front and use a narrower tire at the rear, on the same rim... 
Tires both are Schwalbe G-One Speed 35-622 TR. Rim has 33mm outside measurement, 25mm or so internal width.
Width of those tires:
- Back: 37.4mm @ 2.5 bar
- Front 38.6mm @ 4.0 bar (filled in Tubeless stuff yesterday and pumped up harder, waited for leaks over night, None!)
So YMMV, those "35" tires get wider depending on rim + pressure i suppose. In this light, the front is even more spacy.
The Shimano DI2 FD has only 8mm gap to this tire - see photo for clearance.