Hit a pothole and flatted both Conti GP4000 tubalars at 73km per hour. Near catastrophic accident. The rear rim cracked through it's entire wall. No replacement warranty given. Shimano 7850 C24 full carbon tubular rims are not made anymore, so i am seeking your assistance on a suggested replacement rim. Spoke count is 20.

I would go for a tubular carbon rim like a Corima Winium , they make it in 20 H , 339 euros and 270 gr.