HIA Velo factory tour: This is how they make carbon frames, start to finish

If you ever get the chance to attack a good modern carbon bike with a hammer, do it. Spoiler: It takes a lot of force and multiple hits to damage more than the clearcoat, much more than an alloy or high-end steel bike. The outside layers are always laid up to be stronger and the days of easily damaged carbon are long gone.

This is why they use Innegra.

But these are road bikes. If you are regular,surly bashing your downtube, that seems like rider error.

The ultimate tensile stress of Kevlar is not that much higher than Carbon Fiber, maybe 10% if I remember right. So not much help. With Just one thin layers of it, with the stiff cabon behind it, it would not much obsorb any impact before passing on to the carbon underneath. It’ll prob just mean you get some un-noticable damage under the Kevlar……And mainly, Kevlar is a pain in the ass to work with.

Just putting 2 extra layers of cabon in the layup instead on 1 layer of Kevlar would give you more protection and a stiffer frame, and simpler processes, and happier employees(good to have for a labor intensive product).