What is the rationale for using a gravel-specific wheel for a gravel bike over a lighter cross-country mountain bike race wheel?
I'm looking for a wheel with an internal width of 20mm to 22mm to fit some wide 45mm tires on my gravel bike.
I've seen that some cross-country mountain bike wheels are lighter than gravel specific wheels.
For example, Mavic's new ALLROAD ELITE UST DISC has a 22mm internal width and weighs 1720 grams. But Mavic's CROSSMAX PRO cross-county wheels also measure 22mm internal width but weigh 1595 grams, for only $200 more. Both wheels have bladed spokes and a similar depth for aerodynamic purposes.
If this is the case for wheels generally, what factors contribute to the rationale of choosing the heavier gravel specific wheels over the lighter cross-country wheels?