The A-PEN 68 Development ChroniclesVol. 4: The Failure of the Simple Downsize

After connecting with the teams at Flagship and Top Butler, I gained a deep understanding of the current "Chinu Top" (topwater Bream) movement. This sparked a memory of an old project: the A-PEN 60 prototype. I decided to use that original mold as a baseline and re-engineer it to meet the brutal demands of modern saltwater finesse fishing.

My goal was clear. The lure had to remain a "Bass First" tool that was versatile enough for both spinning and baitcasting tackle. Most importantly, it had to retain the soul of the A-PEN 90: that signature long-distance castability, effortless walk-the-dog action, and the iconic One-Knock Sound.

This journey eventually led us to the A-PEN 65 in the summer of 2024. But getting there wasn't easy.

The Identity Crisis of the A-PEN 60

When I first showed the A-PEN 60 prototypes to the experts at Flagship and Top Butler, one glaring issue haunted me. We couldn't fit the signature "One-Knock" internal rattle system into such a small frame.

The physics simply didn't work. The internal cavity of the 60mm body was too narrow. Instead of the sharp, rhythmic "clack" that echoes underwater, all we got was a faint, cheap-sounding "rolling" noise.

To make matters worse, the early 60mm version used a fixed-weight system to prioritize casting distance. It flew well for its size, but it lacked the "call to action" that defines the A-PEN series.

"If it doesn't have the knock, it isn't an A-PEN."

Breaking the "5-Gram Barrier"

During our development meetings, a consistent piece of feedback kept surfacing: "5g or 6g is too light."

For modern urban topwater games, anglers want a lure they can punch out on baitcasting gear, even in a breeze. The consensus was that we needed a minimum of 7 grams. This was echoed by TK Takuya, a local topwater legend who joined our testing team. In his first session at the Muko River, he landed a Bream on an early sample but was blunt with his feedback: he wanted more distance and more presence in the water.

I realized the A-PEN 60 had reached its limit. To get the weight and the sound right, I had to go bigger. We stepped up to 65mm.

The Turning Point: The Move to 65mm

While 5mm sounds negligible, in lure design, it’s a world of difference. That extra volume gave us the "room to breathe" inside the body. Suddenly, we had the space to re-integrate the One-Knock rattle system without sacrificing the weight needed for long-distance casting.

By moving to the A-PEN 65, we finally hit the four pillars of our design goal:

• Baitcasting Compatibility: Heavy enough to load a rod properly.

• The Sweet Spot: A realistic 7g to 8g weight class.

• Superior Flight: Maintaining the A-PEN’s reputation for distance.

• The Signature Knock: The return of the high-frequency acoustic appeal.

The A-PEN 60 was a proof of concept for "small," but the A-PEN 65 became the "minimum effective size" to keep the brand's DNA intact. It was the moment the project truly came to life.

Next Time: We take the A-PEN 65 prototypes to the lake. Join us for "Vol. 3: Field Testing – The Bass Perspective."

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