The Silicone Standard

I want anyone from an F1 shop to walk into our facility, watch us pull a frame out of the mold, and say, "That's legit."

That's the standard I'm building to.

Not because we're trying to make a racing car. Because the people pushing the hardest on what composite materials can do are in aerospace and motorsport, and if your process wouldn't pass their smell test, you should probably ask why.

Most of the bike industry wouldn't pass it.

That's not an accusation. It's just where the technology is. The manufacturing practices that dominate bicycle frame production are about 20 years behind those of the best composite shops in the world. The gap exists because bikes don't fail in ways that demand better. They're good enough. And good enough is a hard thing to argue against when it's also cheaper.

But good enough and as good as it can be are very different things. And that distance is exactly where the ride quality we talked about in the last piece either comes into focus or gets lost.

To explain why, I need to take you through how carbon frames are actually made.

95% of the bike industry is using manufacturing practices that aerospace moved past 20 years ago. This is not a small problem.

The earliest carbon fiber frames used wet layup. Dry carbon fiber tow pressed into a mold, saturated with resin, with an inflatable plastic bag inserted to force the layers together as everything cured. It worked. The frames were light and stiff compared to what came before. The process was also imprecise in ways that mattered enormously.

Wet layup gives you poor control over fiber direction. You don't know exactly where each fiber is going. You also have limited control over how much resin ends up in the finished part relative to fiber. Too much resin and the frame is heavier than it needs to be and structurally weaker than the fiber content would suggest.

Bladder molding with prepreg carbon solved both of those problems. Instead of wet layup in a tool, you lay up around a latex bladder using pre-impregnated carbon that already has an optimized fiber-to-resin ratio. You know where the fiber is going. The resin content is consistent. This is where most of the industry landed, and it's genuinely better than what came before.

But it still has a problem. Two, actually.

The first is pressure. A latex bladder can only be inflated so far before it fails. The pressure you can actually achieve is limited, and low pressure means you can't fully compress the fiber layers against each other. That leaves voids between the laminates.

The second is movement. As the bladder expands under pressure, it doesn't hold its shape perfectly. It pulls fibers slightly away from where you placed them. Your design called for fibers at a specific angle in a specific location. The finished frame has fibers somewhere close to that, but not exactly there.

That gap between design intention and finished part is where your mechanical properties diverge from your calculations. Not dramatically. But measurably. And in a material where the whole argument is precise control over how the frame behaves in three dimensions, measurable divergence is a real problem.

A perfectly made carbon fiber part has essentially an infinite fatigue life. The reason people think carbon eventually fails is interlaminate voids. Eliminate the voids, and you eliminate the failure mode.

Interlaminate voids are exactly what they sound like: small gaps between layers of fiber inside the structure. Think of them as weak spots that the material has to work around. Under repeated load, those voids propagate. They grow. And when they reach a critical size, the part fails.

Here's the thing about carbon fiber that most people don't know. A void-free carbon part doesn't fatigue the way metal does. Take an aluminum part and flex it back and forth repeatedly and it will eventually crack. That's metal fatigue. Carbon fiber, made without interlaminate voids and kept within its load limits, doesn't work that way. The failure mode doesn't exist in the same way. The part can theoretically last indefinitely.

The reason people think carbon bikes eventually fail is because most of them have voids. The voids are the problem, not the material.

High-pressure silicone molding is how you eliminate the voids.

Instead of a latex bladder that inflates to limited pressure and moves during cure, we use a silicone mandrel. Silicone expands when heated, and when it's trapped inside a closed mold, that expansion generates pressure that a latex bladder simply cannot match. The pressure is a function of physics. Nothing explodes, nothing fails. The only thing that can break is the external mold itself if you push past the limits.

Under those pressures, the silicone holds the exact net shape of the interior. It doesn't stretch or shift. The fibers stay exactly where you placed them. Your calculated mechanical properties and your finished part's actual mechanical properties are the same thing.

And the interlaminate voids are gone. Completely. The pressure is high enough to eliminate them entirely.

What you get is a frame where the design intention survives the manufacturing process intact. Where what we calculated the bike would do is what the bike actually does. Where the dynamic response we talked about in the last piece isn't approximated. It's executed.

That's the standard I want an F1 engineer to recognize. Not because we're in motorsport. Because the logic is the same. Precision composite fabrication, where the finished part performs as intended.

Most bike frames don't meet that standard. Ours do.

That's not a small thing. It's the whole thing.