boots2000 wrote:Can anyone tell me the actual weight penalty for moving from Canti to hydraulic disc?
Say S-works Crux Canti vs. S-works Crux disc- same build, rims, and tires?
On a Moots Psycho-X RSL, going from permanently fixed (not removable) canti posts to the identical frame with disc post mounts, the total difference going to the new Shimano hydraulic brakes, including added weight on the frame and weight of housings, was 371 grams. That's going from Gore Ride-on canti cables and TRP Euro-X magnesium brakes and 9070 Di2 levers.
When you do your calculations you want to consider the brake mounts, offset by removal of two brake hangars, different weights of cables versus hose (and different lengths required), differences in the hardware itself, and braze-ons for one or the other. Mine was Di2 on both bikes, so the shifter levers weren't a big contributor to the difference. I helped build a team mate's bike with SRAM Red hydraulic, and the difference in weight was a good bit greater. Choice of brake calipers also makes a difference. And don't forget the rotors. I'm on six-bolt mounts so I can't use some of the newest Shimano ones, but there's quite a bit of range in rotor weight. And of course for a cross bike, it isn't so much about prioritizing rotating weight as on road bikes -- you're still hoisting the same weight regardless of where it is.