Keep your ONYX RCR 72V running strong with a complete rear wheel hub motor assembly. Choose the setup that matches your riding style: the proven stock 4T for torque-focused performance, or the wider 3.5T for higher top speed potential and a more aggressive rear tire setup. Variant: 4T Rear Wheel Hub Motor Assembly (1.6" x 17") The original, torque-forward 72V rear hub motor assembly. This is the traditional ONYX RCR 72V spec that delivers the familiar low-end pull, responsive takeoff, and balanced everyday performance. Best choice if you want stock feel, strong acceleration, and maximum compatibility with standard rear tire sizing. Best for: stock performance, torque, everyday riding, OEM replacement. Variant: 3.5T Rear Wheel Hub Motor Assembly (2.5" x 17") A higher-speed rear hub motor assembly paired with a wider 2.5-inch rim. Compared to the 4T, the 3.5T is designed to prioritize top-end speed and can add roughly 10–15 mph of additional top speed potential depending on your setup. With a stock battery and controller, expect more speed with less low-end torque, but you can recover some acceleration by adjusting your controller settings (for example, acceleration timing and power output limits within safe operating ranges). The wider rim also supports a wider rear tire for a more planted look and feel, including up to a 4-inch tire fitment depending on tire model and clearance. Best for: higher top speed, wider tire look, riders willing to tune settings for the best balance. Quick decision guide Choose 4T (1.6" rim) if you want the stock 72V feel with strong torque and acceleration. Choose 3.5T (2.5" rim) if you want more top speed potential and a wider rear tire setup, and you’re comfortable with light tuning to regain some torque.
