The Instinct Powerplay SL Carbon 70 keeps its downtube slim and its motor tucked low, so nothing about the silhouette gives away that it's an E-bike. Dyname S4 Lite drops 30 percent of the weight of Rocky Mountain's earlier motor system while holding onto its 700-watt peak output and 75 newton-meters of torque, so the lighter build doesn't cost us climbing assist. A reach-adjust headset lets us dial in center position or a plus-or-minus 5 millimeter offset, so cockpit fit tunes independently from the RIDE-4 geometry chip. What Our Gearhead(R) Experts Are Saying:"I expected the wireless shifting to hesitate somewhere on a rough descent, and it never did. The SRAM Eagle 90 Transmission held gear through hits that would've thrown off a mechanical derailleur."