Everything you need to know about the S1-X eSkootr

The S1-X eSkootr is at the heart of the eSC championship. Running at the cutting edge of micromobility technology, the S1-X represents the future of sustainable personal transport.

The genesis of the S1-X

Throughout the history of motorised sport, competition has led to innovation. The eSkootr Championship is the latest step in the story of technology transfer from racetrack to the road. With the advancement of micromobility, the first iterations of the S1-X concept were developed in conjunction with Williams Advanced Engineering. In the earliest remit of the electric scooter, at the forefront was a mission to open the sport up to all by keeping the barrier to entry low. After a series of simulations and discussions the first specification of the S1-X appeared. ‍

Testing and modifications

The first iteration of the S1-X was a ‘mule’ vehicle that debuted on the test track in August 2020. This forerunner allowed adjustability with regards to its chassis parameters in which both wheelbase length and angle of the steering tube were modified. By trialling riders of different heights one of the first steps was to find the optimum position of the handlebars. Through a number of test days the ridersall defaulted to a single position, which defined the main architecture and geometry of the S1-X.

‍Bodywork

After the first prototype, a new collaborative partnership began with YCOM who accelerated the production and development of the S1-X. With extensive expertise in designing and manufacturing technology in Formula 1 and sportscars, YCOM brought to the eSC their experience in using a composite fibre for the S1-X’s bodywork based on flax — an organic, grass-like material. Lightweight and durable like carbon fibre, this sustainable product fitted with the eSkootr Championship’s sustainability credentials. ‍

Electrification

The S1-X scooter utilises two compact 6kW electric motors combined with a 1.5kWh lithium ion battery, housed underneath the footplate. Approximately 80% of the volume is consumed by the battery,while the rest of the chassis internals are filled with the power electronics to control the motors — known as the SCU or Scooter Control Unit. The two customised hub motors are connected to each wheel and produce 18-19hp leading to a top speed of at least 100km/h or 62mph. For safety reasons, the battery has been designed around a low voltage architecture at a peak of 60V and 120 amps. Dry ice helps reduce the temperature of the battery between races through thermal conduction to eliminate the need for cooling fans and pumps. ‍

Weight

As a standalone, the S1-X weighs 33kg which is increased to 41kg when the battery is installed. (The addition of broadcast cameras is expected to take overall weight to 42.5kg). However one of the dominant factors in the overall mass window is the rider plus their safety equipment — they are also a consideration in terms of drag and the option to balance performance through software control is an option for the future. ‍

Brakes

The brakes are connected both front and rear wheels from standard motorbike-style levers on the handlebars (right is front brake, left is rear) and utilised heat-treated discs with two-piston hydraulic brakes. Rider preference for the control and use of brakes has resulted in different styles. One option is to apply the front brake to help get the scooter turned into a bend sharply, while others choose to use the rear brake to help rotate the scooter more smoothly into the corner.

‍Controls & mapping

The twist throttle on the right-hand side mirrors a motorbike. The thumb throttle typical to normal escooters was also tested and riders preferred the former, which also includes mapping buttons for the front wheel (rear on left). The mapping presets control the SCU to offer different power deliver for each motor, with five maps for each available in total. This functionality allows the rider and their engineer to finesse differing riding styles. For example, one map setting might deliver more power to the front wheel out of a slower corner to offer greater straight-line speed.‍

Boost button

Similar to the power boosts available in other categories of motorsport, each rider is allowed an extra 20% boost of power from the battery for a burst of speed. By pressing and holding the boost button a timer records the length of time boost is deployed — this will be capped by a time limit which will be decided by the eSC Race Director. The length of time will roll-over across the heats to enable an extra strategic dimension to the racing. ‍

Tyres

Through a partnership with PMT Tyres, a durable butraceable construction has been developed from their intermediate range. With a small tread pattern, it was designed to enable the 11-inch diameter tyre to perform in both wet and dry weather, which is not currently the case for normal escooters.
The tyre regulations will allow the rider to have six sets per weekend, three of each compound: soft and hard. The white eSC labelled tyres are the softer and the yellow labelled tyres with eSC logo are harder. Riders have the option to run one compound on the front and a different compound on the rear if they choose.