Frame Fabrication Demystified

Continuing our deep dive into the Argonaut Way, this week turns to frame fabrication—the stage where individual parts become a complete structure.

Layup defines how each piece performs. Fabrication defines how those pieces work together.

What Frame Fabrication Actually Is

By the time parts come out of the mold, they’re structurally sound—but not finished.

During curing, resin flows through the carbon plies and bonds the structure. Some of that resin collects at mold seams, creating what’s known as flashing. Removing that excess is the first step in fabrication, bringing each part to a clean, consistent surface before assembly begins.

From there, the work shifts from individual components to relationships between them.

Sub-Assemblies and Control

Rather than building the frame all at once, we work in stages.

Sub-assemblies allow us to control alignment and bonding conditions more precisely. Each step builds toward the final structure without introducing unnecessary variables.

The first phase focuses on integrating titanium hardware—dropout threads, headset cups, and the T47 bottom bracket insert. These components are prepared and fit in-house, using tooling we design and machine ourselves to maintain consistency.

Nothing is off-the-shelf in how it’s applied.

Carbon-to-Carbon Bonding

Once hardware is in place, the focus moves to joining carbon structures together.

We use scarf joints—tapered interfaces that allow for even distribution of bonding material and continuous load transfer across junctions. The goal is consistency. No abrupt transitions. No localized stiffness that interrupts the ride.

Bonding is done with aerospace-grade epoxy, applied in controlled amounts to avoid excess while maintaining full structural integrity.

Done correctly, the junction disappears in how it rides.

The Seat Sub

At the center of the frame is the seat sub—the junction that ties together seat tube, bottom bracket, and upper structure.

This is where geometry becomes tangible. Measurements taken during fit are translated into cuts, angles, and alignment that define how the bike will feel under load.

Because the saddle is one of the primary contact points, this area has an outsized impact on ride quality. Small deviations here carry through the entire experience.

So it’s built accordingly.

Final Assembly and Alignment

With the seat sub established and the rear triangle partially assembled, the frame moves into final bonding.

Three anchor points—head tube, seat sub, and chainstays—define the geometry. From there, remaining tubes are cut and fitted to complete the structure.

Everything is dry-fit first. Alignment is checked in all planes before any permanent bonding takes place.

Once bonded, the frame is checked again on a granite surface plate using dedicated measurement tools. This isn’t a visual check—it’s a structural one, ensuring the frame sits true under load.

That accuracy shows up on the road as predictability and efficiency.

What This Stage Determines

Fabrication doesn’t add features. It determines whether the design holds together as intended.

Alignment, bonding consistency, and structural continuity all come together here. If this stage is off, the ride is off.

If it’s right, the bike feels coherent from the first ride forward.