I don't think brake clearance of the fenders will be a big issue. Wheels are 700c with Dyad rims (23 mm wide outside, 18 mm inside), and my tires will range from 28 mm to 38. Not sure I can fit 38s with fenders, but if I can I would want 50 mm fenders. I'm not sure standard cantis like Neo-retros are needed, but I have a set on my 650b that I want to swap out. I think the extra performance of Neo-retros would be better used on a tandem than a single-seat rando bike.