A simple question, many confusing answers.
As I fantasize about various bicycles to replace the current road bike, I wondered who actually makes what frames for which brands. After looking at many of these frames, they all start to look alike, feel alike, and cost roughly the same. Direct to consumer brands like Canyon, Rose, and others appear to offer equivalent quality carbon frames for far cheaper because they don’t have the overhead other brands have in maintaining dealer networks, distributors, etc.
The reality is carbon frames require much more specialization and materials science than most local bike builders can support. Meaning, you probably aren’t going to pay $10k for a basic carbon frame made in your town, state, or in the USA. Every brand wants you to believe they make their own frames and they are just as artisanal as the local bike builder working with Aluminum or Titanium tubes in your neighborhood. As an aside, I have the same questions about the metal in the tubes at the local bike builder, where are they from? Most likely, China.
In doing research into various carbon frames, I ran into a lot of talk about carbon materials science, computational fluid dynamics, and computer modeling of stresses about the carbon fiber itself. Differing wrap and weaving techniques, different carbon fibers used to wrap for different reasons. It’s all pretty fascinating. However, none of this really got down to who makes the final product, a carbon fiber bicycle frame.
The top three providers appear to be Quest Composite Technology, Giant, and TOPKEY. They make nearly every road bike sold today around the world. Giant is the literal giant of the industry, out producing and shipping more bikes than anyone. They also act as an original equipment manufacturer (OEM) for other brands. Quest and TOPKEY appear to make higher end brand carbon frames (among other products), such as Trek, Canyon, and Specialized.
The Inner Ring has a somewhat crowd-sourced list of who makes what frames and what brands are owned by whom. The automotive and motorcycle world have been using the OEM model forever, however they seem more transparent about this fact than the bicycle brands. In the end, it really doesn’t matter to me. It seems odd the bike brands try to disguise or obfuscate their frame partners.