Frame Builder Feature: Sean Doyle from Devlin Cycles

In the world of custom bike frames, craftsmanship, passion, and innovation come together to create truly unique rides. We sat down with a seasoned frame builder Sean Doyle from Devlin Cycles, who has spent over a decade perfecting his craft, blending traditional techniques with cutting-edge 3D printing technology to build bikes that are as functional as they are beautiful. Read on to discover the story behind these expertly crafted steel frames.

How long have you been building frames, and what inspired you to start?

I've been building frames for 11 years. As a lifelong cyclist and a design draftsman by trade, I’ve always been tinkering and dreamed of building bikes since I left school. I've raced in nearly every cycling discipline, but now my focus is mainly on gravel and mountain biking. I started with lugged road frames and transitioned into fillet brazing when I began my Signature series of road and MTB frames.

Can you describe your frame-building process?

I primarily work with steel, using a mix of bronze and silver brazing. While I started with lugs, I've moved to fillet brazing. More recently, I’ve incorporated 3D-printed 316 stainless steel sections with reverse socket-style joints. Looking ahead, I’m exploring TIG welding to further improve the process.

What materials do you use for your frames?

My frames are crafted from steel, using commercially available butted and shaped tubing, along with Promolloy 4130. I also integrate 3D-printed 316 stainless steel for specific parts like the yoke, dropouts, seat stay caps, and more.

Do you use any signature techniques in your frames?

I rely on time-tested fabrication methods, but the real innovation comes from incorporating 3D printing. It allows me to replace areas that would typically take more time and energy to fabricate from scratch. I maintain the fillet brazed aesthetic but use 3D printing to streamline the process for parts like the head tube and suspension pivots.

Any memorable builds that stand out?

Two come to mind: the first Signature Gibraltar road frame withbilam sleeves, and my first mountain bike, the Oisin trail bike.

What challenges do you face as a frame builder?

Where to begin? Building steel frames in a market that leans heavily toward carbon fiber is tough. Also, being in Australia, it’s a small market, and material costs can be high. Balancing frame-building with a day job as a draftsman can also be challenging—there just aren't enough hours in the day to do both!

What are the most rewarding aspects of your work?

The best part is riding my own bikes, and seeing others ride them with a big grin on their faces. Receiving praise from peers is always satisfying, too—it's daunting to put your work out there, but when it's appreciated, it’s worth it.

Is there a frame design you're especially proud of?

Definitely the Jester enduro bike. It’s the evolution of my trail bike platform, refined into a fast, capable, and good-looking race bike—at least in my opinion!

What are your goals for the future of your brand?

I want to keep refining my designs and acquire a bigger slice of the market share so I can transition into full-time frame building. Having my bikes raced at the World Cup or World Champs would be a dream come true and a huge validation of my work.

Are there any new technologies or trends in frame building that excite you?

I’m interested in the continuing refinement of 3D printing, especially its potential to create better bikes more efficiently. I prefer methods that focus on quality and durability rather than jumping on the latest tech trend.

Anything else you'd like to share about your journey?

My brand is built on the idea of crafting purposeful bikes, fabricated to a high standard and designed for their intended use. I strive for simplicity—creating bikes that are built to last, with only the necessary materials and design features. The name comes from my mom’s maiden name, and the logo is inspired by the Devlin coat of arms.

To learn more about Devlin Cycles, head to devlincc.com and connect with him @devlin.cycles on Instagram.