I can’t find any recommended tire widths on the Blackwell site. Does anyone run 19mm on Blackwell 100’s?
I do–the BW100 has a narrow rim and a 18-19mm tire seems to be a great match for it. I’m very partial to Contis, but others most like will say that they are slow tires 
Recently tested a Grand Prix Super Sonic (20) with black chili. Not is the list yet but the data is in a thread on BTR. Crr = 0.00251 with width of 19.7 mm. Not much to it at 134 grams but it tested fast.