KR5V V2 Is Here: Stronger Shaft + Upgraded Sprockets for Unmatched Power

 In the world of high-performance electric vehicles like dirt bikes, electric motorcycles, and go-karts, the motor is the heart of the machine.  Its reliability, durability, and torque output directly impact the riding experience.  At KUNRAY, we’ve earned trust with our popular KR5V motor, widely used in models like MX500, MX650, SX500, RSF650, and other RAZOR and DIY e-mobility builds.



Now, the all-new KR5V V2 has arrived — with structural enhancements that take everything riders love about the original and make it stronger, safer, and more flexible, while maintaining the same trusted performance specifications.


Thicker Motor Shaft: From 14mm to 17mm – Stronger Than Ever

The original KR5V featured a 14mm shaft, which was sufficient for moderate use.  But for off-road or high-torque situations, more strength is essential.  KR5V V2 increases the motor shaft diameter to 17mm, significantly improving torsional resistance and mechanical strength.


A stronger core means smoother power transfer and a more durable ride, especially under heavy load or rugged terrain.


Sprocket Upgrade: Now Compatible with More Chain Types

The V2 version also features a major upgrade in sprocket compatibility.  Previously limited to just #35 sprockets, KR5V V2 now supports #35 9T, #35 11T, and 420 -10T sprockets.


That means more flexibility when optimizing for acceleration, speed, or terrain, and greater ease when replacing or upgrading parts:


Use #35 sprockets with #35 chains

Use 420 sprockets with 420 chains


Expanded sprocket options = better customization + improved ride quality.


Stronger Mounting Design: From 3mm to 8mm Case Edges

Mounting reliability is a major concern, especially for motors under high vibration or impact.  With KR5V V2, the front and rear case mounting edge thickness has been increased from 3mm to 8mm, reinforcing the structure where the motor meets the frame.


The result?  A more secure, vibration-resistant installation — ideal for off-road and heavy-duty use.


Same Trusted Specs, Fully Compatible with Existing Builds

Despite the physical upgrades, KR5V V2 retains all of the original KR5V performance specifications, ensuring seamless compatibility with your current setup:


Voltage & Power: 72VDC / 5000W


RPM: Rated 5000rpm, Peak 8000rpm


Torque: Rated 8.5N·m, Peak 35N·m


Current: 60A rated, up to 100A peak


Cooling: Air cooling


Motor Weight: 5.5kg


If your bike or build supports the original KR5V, V2 will be a drop-in upgrade — no rewiring or reconfiguring needed.


Why Upgrade to KR5V V2?

KR5V V2 isn’t just a minor revision — it’s a comprehensive structural upgrade designed for riders who demand more from their machines.


✅ Thicker 17mm shaft for greater durability

✅ Wider sprocket compatibility for better customization

✅ Stronger mounting edge for more secure installation

✅ Same electrical specs = full compatibility


Ready to Ride Stronger?

Whether you're a dirt bike enthusiast, go-kart racer, or DIY e-mobility builder, KR5V V2 gives you the next level of power, reliability, and customization.

Upgrade your ride today and feel the difference from the core!

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