The Tank Project: KTR 150 Scrambler

“Slow Down for the Better Life” ➞ FEVER’s 150cc Scrambler…  

Most builders would agree that customizing a modern bike to resemble something built 50+ years ago is much more difficult than starting with a vintage bike of that era. However, the result is a custom bike that blends modern advantages in reliability, parts availability, and safety with classic, timeless style. Of course, the very challenge of building such a “retromod” tends to attract a certain type of bold builder, such as the team from Taiwan’s FEVER.

Founder Xiao An started his career as a metalworking apprentice, and his workshop still places a heavy focus on metal-shaping, as well as custom exhausts and wiring systems. 

“FEVER focuses on…custom bikes that look vintage but are engineered with modern serviceability and structure. We believe a handmade part should always have a purpose, a service method, and a lifespan — not only a style.”

In this case, they started with a Kymco KTR 150, a very basic single-cylinder commuter motorcycle popular in its home country of Taiwan, where small-displacement bikes avoid imposing taxes, inspections, and registration fees. Xiao actually chose the 150cc machine precisely because of its rather mundane nature. 

“Transforming an ordinary base into something unique is part of the challenge and fun of this project.”

Transform it they did, turning back the clock on the basic commuter to recall a classic machine…with a few choice 21st-century amenities.

“What would a classic look like if it had been built our way?”

The fuel tank was one of Xiao’s first big projects as an apprentice, and it hung on the wall for years before being used on the project. In fact, the entire bike was designed around this centerpiece, which now bears a humpback whale and lovely pinstriping thanks to Jeffrey’s Finishing Touch.

The frame was heavily modified — only the original backbone and engine mounts are stock — and the rear triangle is a dirt track-influenced design.

“This build is a personal workshop project representing FEVER’s design philosophy and engineering approach — showing what we can do beyond the stereotypical ‘tank and exhaust’ modifications that custom shops are often known for.” -Xiao

The bike is clad in a veritable arsenal of handmade metal components: battery box, side covers, front fender, number plate, seat base, chain guard, sprocket cover, skid plate, etc. These are not bolt-on parts but one-offs that ensure nothing else on the road is quite like this machine. 

The angle of the engine was even tweaked to match the revised frame geometry, and the motor itself was rebuilt and outfitted with a Yoshimura carb and DNA filter. The muffler was built and tuned just for this single-cylinder engine, complete with integrated heat shielding for the rider. 

The bike now stops via a set of modified SR400 drum brakes, which disguise the modern nature of the donor bike and stop the bike quite well, considering the 150cc machine weighs much less than an SR. 

The electrical system was completely redesigned by LinLine Custom. Instead of standard bundled wiring, there’s a circuit board layout with modular terminals that allow for OEM-style diagnosis and replacement. There’s even a hidden digital key and Bluetooth ignition, along with a backup key — trick!

Meanwhile, Jeffrey’s Finishing Touch, who did the pinstriping, also handled the seat, and the keen-eyed observer will notice countless details like handmade chainguard and the vintage-style handrail that reinforces the rear fender and taillight. The enduro-style bars are kept streamlined thanks to mini push button controls integrated directly into the handlebar.

All in all, this is one of the our favorite builds of recent memory — a humble Taiwanese workhorse turned into a British-inspired, single-cylinder symphony of fabrication and design:

“Riding it feels like interacting with exposed mechanics. The visible drum internals, single-cylinder vibration, and tuned exhaust pulse give it character, while the geometry and carb tuning make it surprisingly responsive. It looks like an old bike, but it rides with the logic of a modern build.”

Bravo, Xiao! We can’t wait to see more from your workshop.  Below is our uncut interview with Xiao about the build, along with more photos courtesy of Dong Lin Photography.

KTR 150: Builder Interview

• Please tell us a bit about yourself, your history with motorcycles, and your workshop.

My name is Xiao An, founder of FEVER, a metal-focused custom motorcycle workshop based in Taiwan. Before FEVER existed, I started as a metalworking apprentice.

FEVER focuses on functional metal fabrication, exhaust development, and logical wiring systems, creating custom bikes that look vintage but are engineered with modern serviceability and structure. We believe a handmade part should always have a purpose, a service method, and a lifespan — not only a style.

• What’s the make, model, and year of the donor bike?

Base bike: Kymco KTR 150 (2006)

A Taiwanese commuter motorcycle, chosen because it is often overlooked as a custom platform. Transforming an ordinary base into something unique is part of the challenge and fun of this project.

• Why was this bike built?

This build is a personal workshop project representing FEVER’s design philosophy and engineering approach — showing what we can do beyond the stereotypical “tank and exhaust” modifications that custom shops are often known for.

• What was the design concept and what influenced the build?

We love vintage motorcycles, but we don’t copy iconic designs. Our approach starts with a question: “What would a classic look like if it had been built our way?”

From there, we aimed for a clean silhouette, precise geometry, and visible mechanical character. Every line from the tank to the tail was measured like a product design decision, not just drawn for style. Each part was made to belong to this bike, work logically, and remain serviceable for years to come.

• What custom work was done to the bike?

• Structural & Fabrication
  • SR400 drum brake system transplanted
  • Custom machined spacers, axle, and fork caps
  • Drilled drum cover to expose internal brake mechanism
  • Full custom subframe (only engine mount & backbone retained)
  • Engine angle adjusted to match revised frame geometry
  • Rear vintage-style handrail reinforces fender structure + supports tail light
  • Countless handmade sheet-metal parts: battery box, side covers, front fender bracket, number plate, seat base, chain guard, sprocket cover, engine protector, etc.

• Exhaust & Metal Logic
  • Custom oval muffler, internal geometry tuned for single-cylinder pulse
  • Muffler and engine protector share one structural layout, providing mutual support — not separate accessories

• Electrical System
  • Entire harness newly designed like a circuit board layout, not bundled wiring
  • Fully modular terminals allow OEM-style diagnosis and replacement
  • Controlled by Motogadget m.unit blue

• • Hidden digital key with Bluetooth ignition + backup key in case of battery failure
• Performance & Finishing
  • Fully renewed engine with Yoshimura MJN-26 carb + DNA filter
  • Seat & pinstriping by Jeffrey’s Finishing Touch
  • Riding triangle based on lightweight dirt-tracker ergonomics

• Does the bike have a nickname?

We call it “The Tank Project.” It began from a tank and grew into the identity of the build.

• Any idea of horsepower, weight, and/or performance numbers?

Exact numbers are not the focus. The performance gains are notable in:

• Throttle response
• Mid-range torque
• Acceleration from weight reduction
• Tuned single-cylinder exhaust pulse

It rides like a refined vintage machine — mechanical in feel, but smoother than expected.

• Can you tell us what it’s like to ride this bike?

Riding it feels like interacting with exposed mechanics. The visible drum internals, single-cylinder vibration, and tuned exhaust pulse give it character, while the geometry and carb tuning make it surprisingly responsive. It looks like an old bike, but it rides with the logic of a modern build.

• Was there anything done during this build that you are particularly proud of?

Two things:

1) The electrical system: Designed from scratch with modular logic, hidden aesthetics, and modern safety (Bluetooth ignition, backup key). It functions like OEM engineering but looks completely vintage.

2) Structural metal thinking: Parts such as the muffler, protector, and rear handrail were engineered to share load-bearing roles, not just exist as accessories. This is functional aesthetics — the foundation of FEVER’s style.

• Is there anyone you’d like to thank?

• Linlinexcustom – Wiring layout design
• Jeffrey’s Finishing Touch – seat & pinstriping
• Dong Lin – photography
• Friends and early supporters of Taiwan’s custom community

Follow the Builder

Instagram: FEVER Taiwan