Ventum ES1-GABOUT THE VENTUM ES1 G ELECTRIC GRAVEL BIKE A close sibling of our flagship GS1 gravel bike, the ES1 G is designed to be versatile, capable, and, most importantly, wickedly fast. On top of its Shimano EP801 drive system, the ES1 G is equipped with three dynamic power modes eco, trail, and boost and can take up to 700x50c tires. Completing the Shimano e bike ecosystem is a Di2 electronic drivetrain that features a mix of Ultegra and XT components,