On Wednesday, April 7, 2021 at 4:47:35 PM UTC-4, wrote:
On Tue, 6 Apr 2021 21:09:12 -0700 (PDT), jbeattie
wrote:
A few miles into my evening ride on my
cable-shift Emonda -- with my wife pushing me
on her ebike, I shifted to go up the next hill
and snap -- immediate downshift into 34/11.
(...)

There used to be a company selling carbon fiber brake cable kits
called Power Cordz:
https://www.velonews.com/gear/road-gear/wrenched-and-ridden-power-cordz-brake-and-shifter-cables/
Their web site at:
http://www.powercordz.com
is gone, so I assume that something went wrong with the company or
product. Seems to be a tolerable alternative.
https://forums.thepaceline.net/showthread.php?t=254169
https://www.pinkbike.com/news/power-cordz-review-2010.html
https://www.roadbikerider.com/power-cordz-d1/

If you don't mind risking your bicycle, life, and future, you can
possibly replace the steel brake wire with a different material, such
as carbon fiber or various Aramid fibers such as Kevlar, Dyneema,
Spectra Amsteel Blue, etc. However, if the risk is too much, use the
standard stainless steel cable in rear brake, and the CF or Aramid
fiber replacement in the front brake, until you have some confidence
in the idea.

Remember, you have but one life to give for advancing bicycle tech.

"Understanding The Subtle Differences Between Carbon Fiber And Aramid
Fiber"
https://pur-carbon.com/blogs/news/understanding-the-subtle-differences-between-carbon-fiber-and-aramid-fiber

Kevlar Ropes, Cables, and Fibers"
https://www.dupont.com/fabrics-fibers-and-nonwovens/ropes-cables.html

--
Jeff Liebermann
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

I briefly toyed with the idea of using powercords a few years ago. The thing that put me off was the alleged issue of the cable slipping out of the clamp - apparently it was difficult to get the clamps to effectively hold the cable even when the clamp was tightened to the extreme. I read that on several different forums. One user posted that he wrapped the cable through the clamp twice. I decided it wasn't worth the hassle.