The Ventus 81kW Ultra Bee Ryuga Motor Upgrade is a hairpin stator electric motor made by Ventus for the Sur Ron Ultra Bee, sold here at GritShift. It is a direct plug and play replacement with no modifications: 81 kW peak at 96V, 114 Nm of torque, 14,000 RPM maximum, IP67 sealing and 27.6 lb (12.5 kg) on the Ventus sheet.
Specs verified October 2026 against the live GritShift product page and the Ventus tech sheet.
Specifications
| Product model | Ryuga RGA81 |
|---|---|
| Motor type | Hairpin stator |
| Peak power | 60.3 kW at 72V, 81 kW at 96V |
| Peak torque | 114 Nm at 1400 A, 73 Nm at 850 A |
| Max RPM | 14,000 rpm |
| KV value | 118 |
| Pole pairs | 4 |
| Max efficiency | 95% |
| Insulation class | 250°C |
| Temperature sensor | NTC 10k B3905 |
| Position sensor | Encoder ABZP |
| Cooling method | Natural air cooling |
| Protection grade | IP67 |
| Phase wire gauge | 35 mm² |
| Top speed (tested) | 180 km/h (112 mph) at 72V, 195 km/h (121 mph) at 96V with a 46T sprocket and 62.5 cm wheel diameter |
| Size | Φ173 x 180.8 mm |
| Weight | 27.6 lb (12.5 kg) |
| Controller | Plug and play with Ventus VTB Aetos / V9600 controllers only; others need connector repinning and rewiring |
| Installation | Direct replacement for the Ultra Bee motor, no custom wiring or fitment modifications |
What bikes does the Ventus 81kW Ryuga motor fit?
- Sur Ron Ultra Bee
What does the Ryuga hairpin stator change on the Ultra Bee?
Hairpin winding improves slot fill and thermal efficiency compared to conventional wound motors, which is how Ventus gets 60.3 kW at 72V and 81 kW at 96V out of a 27.6 lb (12.5 kg) motor that still installs as a direct replacement. Peak torque is 114 Nm at 1400 A of phase current and 73 Nm at 850 A, the winding is 118 KV, the phase wires are 35 mm² and the motor spins to 14,000 rpm. The full table, performance curves and efficiency maps are in the Ventus Ryuga 81kW specification sheet linked from the product page.
How fast has Ventus tested the 81kW Ryuga?
On the Ventus sheet the tested top speed is 180 km/h (112 mph) at 72V and 195 km/h (121 mph) at 96V, measured with a 46T sprocket and a 62.5 cm wheel diameter. Those are the manufacturer's tested figures at that stated gearing and wheel size, and they sit alongside a 95% maximum efficiency rating, natural air cooling and a 250°C insulation class.
Which controller does the Ventus 81kW Ryuga need?
Only the Ventus VTB Aetos / V9600 family is plug and play with this motor; Ventus notes that any other controller means repinning and rewiring the connectors. The Ventus Aetos Pro V9600 Controller and the Ventus Aetos Max V9600 Controller we carry both unlock the controller tuning, real time motor monitoring through the NTC 10k thermistor and Encoder ABZP position sensor, and the programmable riding modes the drivetrain was designed around.
Where can I buy the Ventus 81kW Ultra Bee Ryuga Motor Upgrade?
Right here. We sell the Ventus 81kW Ultra Bee Ryuga Motor Upgrade at GritShift, made by Ventus. Browse every Sur Ron Ultra Bee part we carry in our Sur Ron Ultra Bee Parts collection.
