High performance sprocket made specifically to fit the tapered shaft QS Motor 138 4000W 90H Motor. Sprocket comes complete with 5mm key bar. This sprocket works well with 520 standard and O-ring chains.

This sprocket fits the tapered shaft version of the QS 138 90H motor.

Tapered bore dimensions: 21.5mm diameter to 24.5mm diameter
Keybar width: 5mm

IMPORTANT (Instructions for Installation):
When attaching this sprocket to the tapered shaft DO NOT torque down the shaft nut with excessive force. Over torquing the shaft nut on the sprocket could cause the sprocket to crack due to over expansion down the tapered shaft. Fitment of the sprocket and shaft nut should just be snug. For best fitment it is recommended to use a bushing between the sprocket and bearing race, use thread lock on shaft nut and tighten shaft nut to no more than 10 ft/lbs of torque. Amp Sprockets can NOT be held responsible for any sprockets that have cracked due to over torquing on tapered shafts during installation.