Rotor’s new QXL chainrings (left and center, standard on the right) have 16% ovalization compared to their normal rings’ 10% change.
In tooth counts, that means the 53T feels like a 49 to a 58, versus 51 to 56 for their normal rings. It’s available in standard and compact, only for road and only in a 53/41 combo with 130BCD and 53/38 for compact. The reason the compact still has a 53T big ring is because they needed the extra size to accommodate the smaller cross section where it’s effectively a 49…and because their sponsored pros wanted a proper big ring for the flats but something smaller for the climbs.
They’ll have a 52/36 compact option coming soon. Retail is $320 for the pair. Following that, they’ll add a 53/38 for Shimano’s new DA9000 cranks, which lets them keep their rings on Shimano-sponsored athletes.