Inside Airtight Cycles’ Brooklyn Studio

We speak with Mathew Amonson about building beautiful Möbius-style bikes by hand

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Just over two years ago, Mathew Amonson began toying with the idea of building himself a custom bicycle. Research turned to experimentation, which then led the Brooklyn-based enthusiast to travel to Colorado to study under legendary bicycle builder Koichi Yamaguchi. There, Amonson learned the traditional frame-building techniques that he now employs under his own newly established label, Airtight Cycles. Working with steel, bronze and silver in the development of his signature Möbius frame design—a combination of tight track geometry in the back and more relaxed criterium frame in front—the emerging designer now has a handful of custom frames under his belt, and plenty of ideas for the future.


As one would imagine, the process of hand-building bicycles requires a significant amount time, patience and design knowledge. Not to mention a particularly acute eye for detail. Luckily, as a stop-motion animator by trade, Amonson is well-equipped to handle all aforementioned constraints. Plus, as an experienced creative, he was quick to recognize the value in working directly with clients to determine the required fine print for each frame.

“As you’re building, it’s great to get to know [the person] that you’re actually building for because it changes the way you look at the frame,” explains Amonson. “Every single time I’m looking at details, I’m thinking about how they’re going to look at them, how they’re going to appreciate them, and how they’re going to ride it and what they’re going to feel. I try to put my character into it, but it’s for somebody, so it should have their personality reflected in it as well.” Obvious as it might seem, openness to working intimately with each customer can be rare in the field, though this approach helps Amonson achieve a higher level of precision.

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You can tell how much somebody loved the bike when they were building it if you pay attention to the details.

As for the technical process itself, Amonson relies heavily on hand-centric techniques developed while working under Yamaguchi. While many custom bicycle builders use lathe machines and other equipment to save time on multiple concurrent builds, Amonson works on frames one at a time, relying on his hands and sturdy files to precisely create each detail. This hands-on approach is especially noticeable on his dropouts, which use a double miter to achieve a unique aesthetic. “If you look at handmade frames, you can tell how much somebody loved the bike when they were building it if you pay attention to the details.”


Favoring fillet brazing and lug-less frames, Amonson has selected the rarely seen Möbius style frame design as a signature. The fusion of track and a criterium geometry is characterized by asymmetric seat stays (the two steel tubes connecting the top tube to the rear dropouts). The look is attractive and functional. “With the Möbius stays, the drive side stay is lower to make the triangle tighter on the low end, which means there’s less flex when you’re peddling so more energy is transferred to pushing you forward,” he explains.

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Contact Amonson directly for pricing on custom builds, and keep an eye on his site for build updates and where to find Airtight Cycles at upcoming meets in the NYC area. For a closer look inside the Airtight Cycles studio, see the slideshow.

Photos by Graham Hiemstra