SRAM has revealed what it calls the E2 Electric-Assist system at Taichung Bike Week.
Following its take over of German hub gear specialist Sachs, SRAM appears to have drawn on the engineer's experience to develop a two-speed hub motor system, however any changes between the two will be automatic, not manually activated. Just one cog is used front and rear, meaning the gear ratios remain unchanged, while the torque output increases or decreases.
The only wiring present spans from the rear wheel to the battery, which carries and on/off switch.
Bike Europe has more information from the show floor, here.