The Ventum ES1-G is a performance-oriented electric gravel bike that takes the brand’s GS1 carbon gravel platform and adds a high-power Shimano EP801 system. That gives it a notably different brief from lightweight, low-assist e-gravel bikes: with 85Nm of torque, Class 3 assistance up to 28 mph, and a removable 504Wh battery integrated into the downtube, the ES1-G is built to cover ground quickly and handle steeper terrain with less compromise in speed. Its full carbon frame and fork, internal routing, flat-mount brakes, and UDH compatibility place it firmly in the modern premium e-gravel category rather than the adventure-touring end of the market.
What distinguishes the ES1-G is the way it combines a race-influenced gravel chassis with a full-power mid-drive system and Shimano’s electronic integration. Ventum pairs Ultegra Di2 shifters with an XT rear derailleur to access Shimano Auto Shift and Free Shift functions, an unusual but logical setup for an e-bike intended to smooth cadence management over variable terrain. Tire clearance up to 700x50c broadens its range beyond hardpack gravel, but the bike’s stated aggressive geometry suggests it is aimed more at riders who want a fast, assertive e-gravel bike for training, spirited mixed-surface riding, and high-speed commuting than a relaxed all-road machine.
Where to get it.
No retailers stocking size S.
No retailers carrying size S right now.
Spec sheet.
Every component shipped with this build.
Geometry & fit.
6 sizes published.
The ES1-G’s geometry is notably progressive for an e-gravel bike, with a long front center, relatively stretched reach, and size-specific head tube angles that steepen as sizes increase. Reach numbers run from 399mm in XS to 441mm in XL, while chainstays stay fixed at 435mm across the range. That points to a bike with stable weight distribution and a purposeful, forward riding position. The smaller sizes use especially slack front-end figures for gravel—69 degrees in XS and 69.5 degrees in S—paired with high trail numbers of 86mm and 82mm, which should calm steering and add confidence for smaller riders who might otherwise get twitchy handling from scaled-down frames. Larger sizes sharpen progressively to 72-72.5 degrees with trail dropping to 65mm and 62mm, keeping steering response from becoming overly slow.
A consistent 70mm bottom bracket drop and 72.5-degree seat tube angle across all sizes suggest predictable fit and handling throughout the range. Stack and reach figures are fairly aggressive rather than upright, particularly in the M (545/414) and L (589/432), reinforcing Ventum’s race-bred positioning. Combined with the 435mm rear center and wheelbases from 1049mm to 1091mm, the geometry should deliver a planted, high-speed feel with enough front-end stability for rough gravel, while still preserving the directness expected from a performance-focused drop-bar bike.
Where the handlebar sits relative to the bottom bracket — the single most important fit pair.
01Fit geometry6 values
02Component geometry4 values
03Handling geometry8 values
Which size should I buy?
Slide your height to see the recommended size. GearWise's fit algorithm works from the published stack, reach, and ETT — the brand's own recommendation may differ.
→Calculated from GearWise's own stack / reach / ETT algorithm — the brand's size chart may recommend a different size, and a proper bike fit beats any calculator.
The lineup.
1 build, ranging $5,999.
The ES1-G is offered in a single Electric Gravel Bike build at $5,999, which places it in the premium but not top-tier end of the carbon e-gravel market. The core of the value proposition is the drivetrain and motor package: Shimano’s EP801 drive unit with 85Nm of torque, a removable 504Wh battery, and a mixed Di2 setup using Ultegra shifters with an XT rear derailleur. That configuration is notable because it enables Shimano Auto Shift and Free Shift, features that make particular sense on an e-bike where maintaining cadence and managing shifts under load matter more than on a conventional gravel bike.
Beyond the drive system, the frame itself carries contemporary standards expected at this price, including a carbon frame and fork, internal cable routing, flat-mount disc compatibility, UDH, and clearance for 700x50c tires. With only one build available, buyers are effectively choosing into Ventum’s intended concept rather than sorting through multiple spec tiers: a fast, electronically integrated, full-power e-gravel bike with a strong emphasis on performance and system cohesion.
