These days, the methods used to build custom motorcycles are as diverse as the designs themselves. Some builders lean on modern tech like 3D design and printing, while others prefer to work directly with metal. This custom KTM 390 Duke rolls a whole lot of approaches into one spunky scrambler.
The Duke belongs to Akash Das, a graphic designer in the advertising industry, who’s based in Mumbai, India. Akash and his wife, Garima (also a designer) have a multi-disciplinary design side project called Busy People, where they play with ideas that don’t fit into their day jobs. Sometimes, that includes designing custom motorcycles.
“Motorcycle designs have slowly became a big passion for me,” says Akash, “and I started working on them, along with my job. This KTM took a little more effort than part-time attention, so I had to take a sabbatical to finish it.”
Busy People’s method is to design everything in-house, then outsource any tasks that they can’t handle themselves. Here, Akash designed many of the custom bits using 3D software, then 3D printed prototype parts, before having the final pieces machined from aluminum by third parties. The prototyping stage meant that each part could be tested for fitment—avoiding any surprises during final assembly.
Akash wanted to turn the 2018-model 390 Duke into a neo-retro scrambler, so he started with the subframe. He designed a new unit that would bolt straight to the OEM mounting points—but with a shorter and flatter layout. “This first change revealed the skeleton of a scrambler,” he says.
The seat foam was shaped in-house, then sent off to be wrapped in synthetic leather. The tail tapers into a custom finned aluminum part that hosts an array of taillight LEDs, with a custom luggage rack above, and a stubby fender below.
Up front is a custom-made headlight nacelle, wrapped around a JW Speaker LED headlight. The cowl, along with the taillight surround, fender mounts, gas cap and front sprocket cover were all 3D-prototyped before being machined from 6061 T6 billet aluminum.
Thinner parts like the sump guard, radiator guards, luggage rack and base plate for the seat were water-jet cut from 3 mm aluminum sheet. Akash then bent and assembled the parts before fitting them. The fenders were made from fiberglass, formed over 3D-printed molds.
The tank took some heavy lifting. It’s a two-piece design, with a hidden fuel cell designed to mimic the bottom of the original 390 tank, and a shapelier cover to go over it. And since many suppliers were closed due to COVID-related lockdowns, Akash had to shape the aluminum for both items himself.
The inner reservoir uses a CNC-machined plate to host the fuel pump, and bolts to the stock mounting points. Akash first built the outer shell out of wood, then fitted the aluminum over it.
“What you see on the bike is the fourth tank,” he says, “the earlier three were scrapped as I was shaping aluminum sheet for the first time. I kept it flatter and boxy to go with the naked trellis frame, but gave it little curves at the bottom to integrate the side panel, again inspired by the trellis frame. This little detail gave it a bit of the classic tracker vibe.”
Next, Akash ditched the Duke’s alloy wheels for a pair of spoked units with Pirelli Scorpion Rally STR tires. They use 17” Akront rims, with new hubs that were modified to work with the KTM’s stock ABS system. There’s a new Galfer disc up front, and the sprocket mount at the back had to be altered to get the chain alignment right.
Final touches include an off-the-shelf muffler, custom handlebars, a custom radiator coolant overflow tank, and tiny blank-off plates just in front of the tank. Akash’s trusted mechanic Dheeraj helped on a lot of the technical stuff, including rerouting the fuel lines and reworking the wiring.
“Routing and wiring a motorcycle neatly is an art which you will hardly see,” says Akash, “but you feel it when the motorcycle just works perfectly. The graphic designer in me can appreciate neat layouts of any kind.”
The paint was handled by Nikki Garage; a simple grey to highlight the Duke’s skeleton as much as possible. A small motif on top of the tank bears Akash’s personal mantra: “Distance over time.”
“It took almost two years to build this motorcycle,” he says, “which included lockdowns, a fractured leg and learning Fusion 360 software. But it was absolutely satisfying to see the transformation—from drawings on paper, to CAD, and then those CNC blades giving shape to the parts exactly the way you imagined.”
Akash’s 390 Duke is now complete, but his sabbatical isn’t—so he’s using the rest of it to cram in as much riding as possible. He’s not being gentle either: keen eyes will spot bits of dirt that didn’t quite come off for the photos, and a fresh ding in the front rim.