Fully redesigned for 2018, the YZ450F continues atop Yamaha’s motocross lineup with a new electric-start engine, a new chassis with improved suspension, and revised styling. Most impressive is the engine’s connectivity to Yamaha’s smartphone app. Just a few years ago, leading production bikes came with various couplers you plugged in to access different power modes. No more. Now, just download the free Yamaha Power Tuner app from Google Play or Apple’s App Store, pair up the YZ450F via Wi-Fi, and then select among “Hard Hitting” for loamy tracks, “Linear Torque” for hardpack, or “Smooth Linear” for slippery conditions to optimize power delivery.