Originally Posted by
Sy Reene
I guess that's kinda what I'm asking. In what way does a 23c rim run a 40mm tire better than eg. a more run of the mill 19-21c rim?
I'd probably myself opt (if I had disc brakes) for something like the DT RR421 rim sizing.
Supposedly there is an aero benefit. Wider rims means less light bulb shape to the tire so more even airflow. No idea if this is true, but my wheel builder, in recommending Belgium plus over Belgium C2 for my road bike, claimed they offered “20% better performance both in aerodynamics and cornering” when paired with standard 23 or 25mm tires.