TLDR - Motor Dropout

Not knowing a QS motor’s phase wire gauge? Not cool. The answer is below-because size does matter. The QS motors with 155mm and 200mm dropouts fit the stock swingarm, though the 200mm requires spreading it apart by about 2"-don’t worry, it can handle it. The stock swingarm dropout slot is 11mm tall, while the 155mm dropout is 12mm and the 200mm is 14mm, meaning a little filing is needed. But hey, if you can file your nails, I’m pretty sure you can handle this-time to prove you’re a big boy!

Motor Wire Gauge

Thicker phase wires mean more power-just like how 6-gauge wiring outperforms 8-gauge when handling high current. Compare the motors below, considering their release year, the configuration QS MOTOR offers, dropout size, and phase wire gauge.

Year Motor Dropout Gauge
2020 273 V3 150mm 8 AWG
2024 260 V4 155mm 6 AWG
2020 273 V3 200mm 6 AWG
2025 273 V4 200mm 6 AWG

Motor Dropout Slot Filing

As shown in the chart below, a motor with a 155mm dropout requires filing the dropout slot by 1mm, while a 200mm dropout requires 2mm of filing. In the image, file the red-highlighted area of the rear swingarm dropout slot to fit these motors. Keep the yellow-highlighted section untouched to preserve compatibility with the original 205 motor with a 150mm dropout.

Motor Shaft Dropout Filing
260 V4 12mm 155mm 1mm
273 V4 14mm 200mm 2mm

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Motor Dropout

The dropout size of a QS motor determines axle strength, and torque handling. Larger dropouts can support thicker axles, better torque arms, and sometimes thicker phase wires, but performance depends on the specific QS Motor configuration.

The dropout size of a QS motor refers to the spacing between the dropouts (the slots in the frame where the axle sits). It plays a crucial role in several factors.

  • Axle Thickness & Strength: Bigger dropouts often mean thicker axles, which improve durability and resistance to torque forces.

  • Torque Handling: A wider dropout allows for better torque arm fitment, reducing stress on the frame and preventing axle spin-outs.

  • Heat Dissipation & Performance: Some larger dropout motors may have thicker phase wires or better heat management, but this isn’t always the case (it depends on the QS Motor model).

  • Battery & Controller Pairing: Bigger dropouts may indicate a motor designed for higher power applications, meaning it can handle more current from the controller and battery.

So while a larger dropout size can hint at a more powerful motor, it doesn’t automatically mean thicker phase wires or better performance-it depends on the specific configuration QS Motor is offering.

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