NOTE: If you find a new source, please let me know by email and I will add it here
Here is a list of possible sources of continuous length pultruded carbon fibre:
Continuous length pultruded carbon strip - 1x10mm, 2x12, 3x12, 3x15, 4x20 and many other sizes!
https://cacomposites.com/sheets-strips/pultruded-carbon-fiber-strip/
Possible long lengths on request:
http://rbjplastics.com/standard-profiles/carbon-fibre-strip.html
https://www.alibaba.com/showroom/pultrusion-carbon-fiber-strips.html
http://www.marskeaircraft.com/carbon-rod-pricing.html
https://www.dpp-pultrusion.com/wp-content/uploads/2019/01/DPP-specification-sheet-2019.pdf
Dongguan Juli Composite Technologies, Ltd;
Custom sizes and lengths of pultruded carbon fiber – great service, low, low prices
https://carbonfibertech.en.alibaba.com/company_profile.html?spm=a2700.galleryofferlist.0.0.5a394bf958zl8J#top-nav-bar