Electric KTM 65 SX

Goal:

The goal of this project was to build a similarly sized adn portable bike but also with a massive step up in frame design/ build quality and suspension. Instead of heavily upgrading a kids toy frame, the deal on this was much cheaper than it would have been to upgrade the suspension on a Razor. The goal of this bike was to also create a much more capable bike for trail riding and actaul offroad use while still being in a small, portable and light package.

How:

Takeaways:

With a 3D scanner, and access to a waterjet and TIG welder, as well as a lot of past experience building multiple electric vehicles with similar powertrains, it was very fun to see the whole project come together on such a short timeline

About:

Time: January 20-23 2026 for the powertrain

Skills:

Fabrication: 3D scanning, Waterjet, TIG welding, 3D printing, soldering

Software: Fusion 360 (deisgn and FEA)

Stats:

Motor: 14Kw+ Kunray KR5V

Battery: 60v 24Ah currently, 72v 20Ah custom built battery soon

Controller: Fardriver 72450, 195A line, 350A phase

Speed: 55mph+

Range: 35+ miles

Weight: 125lbs

Electric Powertrain Design Overview

3D scanned

The first step in the conversion was disassembling and 3D scanning the frame in separate parts to recreate a digital model with hideable sections to enable easier modeling

Designed

Using scan data to ensure correct chainline I designed an electric powertrain swap without modifying the frame. 16 waterjet and 7 printed parts. including a rear sprocket for #35 chain for optimal gear ratio with the new motor

Waterjet

The battery and motor mount were designed to be waterjet and then welded together. Breif FEA was done on the motor mount and rear brake spring mount

TIG welded

After all the parts were waterjet, the motor mount and battery mount assemblies were welded together and assembled on the frame

Full Build Timeline

December 17, 2023

I picked up a KTM 65 SX off of Facebook Marketplace with a seized engine for this swap. I was looking for a name brand frame with quality suspension, as those were both things lacking on my previous builds, and safety and comfort was a priority for this build.

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