High Torque 520 12T Racing Sprocket
Designed specifically for QS 138 70H V3 and QS 138 90H V3 geared motors. Constructed from hardened steel for maximum durability and galvanized in silver to resist corrosion.

IMPORTANT FITMENT NOTICE:
This sprocket is engineered for use with QS 138 70H and 90H V3 geared motors only. Before ordering, please measure your motor shaft carefully to confirm compatibility.

The spline profile of this sprocket is as follows:

• Widest inner spline diameter: 16.9mm

• Narrowest inner spline diameter: 14.3mm

This is a press-fit sprocket and must be tapped into place using a mallet and a block of wood.

We test-fit each design to actual QS motors during production to ensure the best possible fitment. Every sprocket is manufactured with strict tolerances and goes through quality control checks on the production line.
If you experience difficulty during installation, it may be due to minor inconsistencies in QS motor shaft dimensions, which can vary slightly between manufacturing batches.