How Circa’s MABEL™ System Re-Thinks Bicycle Manufacturing

Circa is more than just one bike. It’s an entirely new way of making and delivering bikes to people. As we’ve said before, our goal is to create locally made bikes, just for you, in less than ten days and starting at less than $2,000.  To make this possible, we needed to seriously rethink how bikes are made. Ultimately, we created a new manufacturing platform that we call MABEL™.




We took a close look at why bike manufacturing using traditional methods has mostly left the US. Here’s what we learned:


Five enemies to making affordable bikes in the USA:


Horizontal Enemies


How Circa’s MABEL™ Process Innovates to Challenge Traditional Methods for Building Bikes:


Adhesives replace Heat

The heat that I’m talking about comes from the welding and brazing of traditional frame building. Heat creates a bunch of issues, but the biggest challenges are that it’s a high-skill operation, and cleaning up the welds afterwards takes a lot of time. Our substitute for heat is our modular and bonded lug system that we call MABEL™. Yes, I did say “bonded”. More bluntly, I could also say “glued”. We use aerospace-grade structural adhesives as a key element of our construction methods. If you think about it, airplanes and race cars are bonded together. There’s no reason not to bond bikes, too. Also, remember that ultimately, carbon bikes are primarily glue with carbon fiber in it. We’re not re-inventing the wheel with this idea, just making it better.


Anodizing replaces Paint

Paint is a really common way to finish bicycle frames, but it’s also very expensive and time-consuming when done here in the states. To get around paint, we use a process called anodizing that lets us apply color to our frames in a way that’s more durable than paint, very quick to apply and extremely cost effective. Even better is that when anodizing is done with the right attention to detail, it’s very beautiful. In Portland, we’ve got several excellent anodizers, and they’re great to work with.


CNC replaces Tooling

In simple terms, tooling refers to the molds that are needed by factories to shape molten metal and plastic into fun shapes like toothbrush handles, curvy cars and bike parts. It’s expensive and only pays for itself if you’re making huge numbers of things. Tooling is also not particularly flexible if you want to make changes to your designs. We rely extensively on computer-controlled milling machines (also known as CNC) to create the key elements of our frames. CNC is awesome because it allows us to work in small batches, and design changes can happen as easily as a programming change. The other upside on CNC is that many of our Portland-based CNC vendors use machines made in California.


Labor is reduced by Innovation

Bikes made by hand in the states through traditional methods can take 50-100 hours to build. That’s a LOT of time, especially when factoring in a reasonable wage for the craftspeople doing that work. Our entire process is designed to reduce the hand-labor portion of the manufacturing process. Once we have all of the components of our frames prepared, actual assembly and completion takes about 10 person-hours or less.


Modularity solves for Geometric Complexity

The last factor that really affects cost is what we call geometric complexity. Without geeking out too much, the basic challenge is that many of the angles of a bike frame change a little as you scale the design for different frame sizes. The modular nature of our MABEL™ manufacturing platform makes it really easy to deal with all of these slight angle changes. As we move forward, this aspect of the system will also make it possible to create very affordable custom geometry for customers who require it.


I hope that this first overview of MABEL™ gives you some deeper insight into how Circa is working to innovate and create exquisite, affordable bikes in the USA. I’d love to hear your questions or comments. You can see the MABEL™ system in action on our Trillium frame and bikes by following these links:

Trillium Frame

Trillium Road Bike

Trillium Urban Bike




Rich Fox | Founder


Founder-Road Med


2 Responses to “How Circa’s MABEL™ System Re-Thinks Bicycle Manufacturing”

  1. Matt Rawdon

    I like where you are going.
    Early aluminum bikes had much larger diameter tubes to get enough stiffness.
    Does the construction of your lugs, especially the bottom bracket, allow the sleeve of the lug to fit inside the tube instead of outside?


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