Until then, I’m sticking with the rim brake setup I have…
I was just on a podcast as a guest (Cycling Time Trial Podcast) for an upcoming episode. We talked a bit about how rim brake bikes are still pretty fast compared to disc brakes.
When Kiley, Heath, Dave and I did the Aerobike Shootout at A2 I talked with the people at Cervelo who designed the P5X. They told me the P5X would have been about 5w faster with rim brakes.
IDK think the P5disc is 5w faster than the p5x.