Improving the efficiency of traveling on a Zero has a significant effect on range. The powertrain efficiency is high enough (few internal losses) that most gains should focus on aerodynamic drag reduction and rolling resistance.
Motorcycle aerodynamics is a complicated topic, and most riders should focus on a simple windscreen that improves comfort and keep their body behind that. A good third-party windscreen when adjusted properly should provide a 5-10% increase in range.
To go further, the entire shaping of air around the vehicle and rider has to be considered, especially the transition from laminar flow to turbulent flow around the front of the vehicle, then the rider, and around the tail.
Drag is also related to the vehicle's airspeed, not its groundspeed. Any headwinds, sidewinds, or (lucky) tailwinds will impact the design significantly. A robust design can handle a lot of variation and not lose performance.
- Tony Foale
- Sport Rider wind tunnel tests
- Kraig Schultz
- Craig Vetter's last fairing timeline
- Terry Herschner's Vetter Streamliner based on a 2012 Zero S
Crouch down! Behind something, if possible.
Total Cross Section
Oncoming air should be smoothly curved around most of the rider's body.
Air as it passes any fairings or the rider's body will detach if the transition is abrupt for the current velocity.
Rolling resistance relates to the wheel bearings (sliding friction) and the tire contact patch with the road (rolling friction).
Broadly, a more street/touring oriented tire will offer less rolling resistance than a knobbier off-road tire.
Higher tire pressure will reduce rolling resistance for any tire, but does raise the tires sensitivity to rough roads and particularly sharp objects that could puncture the tire.
Carrying a portable (12V or 120V) tire pump is a solution for wanting to adapt the tire pressure based on what a long trip demands in different sections.