These specifications are for the standard HT i180 model. Segway also offers four additional models: the HT i180 Police, the Cross-Terrain Transporter (XT), the Golf Transporter (GT) and the p133, a small, lightweight model. To view additional specs, check out Segway's Products page.
- Top speed: 12.5 miles per hour (20 kph). This is about three times typical walking speed.
- Weight: 83 lbs (38 kg)
- Width: The Segway's footprint (how much space it covers on the ground) is 19 by 25 inches (48 by 63.5 cm). This makes the Segway about the same width as an average size person, so it doesn't take up much space on the street. The platform is 8 inches (20 cm) off the ground.
- Weight capacity: 260 pound (118 kg) rider and cargo.
- Range: About 17 miles (28 km) on even ground, with a single charge on a lithium-ion (Li-ion) battery, and 8-12 miles with a single charge on a NiMH (nickel metal hydride) battery.
- Driver interface: The Segway has a small LCD screen that tells the driver how much battery power is left and how well the vehicle is functioning. The screen displays a cartoon face, which expresses the general condition of the vehicle.
- Motors: Each of the Segway's wheels is driven by a 2-horsepower electric motor that produce no emissions.
- Transmission: The two-stage transmission, built by Segway and Axicon Technologies, has a compact 24:1 gear ratio. It uses a helical gear assembly that significantly reduces noise. The Segway team configured the two meshes in the gear box (the points where gears connect) to make sound exactly two octaves apart. This means the sounds are in harmony, so the gear box make a more musical noise. The gears are also designed to have noninteger gear ratios, meaning the gear teeth mesh at different points from revolution to revolution. This minimizes wear and tear to extend the life of the gear box.
- Computer: The Segway's brain is made up of two circuit boards, housed in the vehicle's chassis. The circuit boards, which boast a total of 10 microprocessors, normally work together, but each can function independently in the event of a computer problem. If one breaks, the other circuit board will slow the vehicle down gradually to avoid an accident.
- Power: The Segway is powered by two rechargeable batteries. Segways come with either lithium-ion (Li-ion) or nickel metal hydride (NIMH) batteries. The batteries are constantly monitored by a circuit board, which communicates any performance problems to the central brain. The batteries can be recharged with household AC current. Dean Kamen estimates a Segway costs somewhere around 5 cents a day in electricity bills.
- Sensors: The Segway uses five gyroscopes and a collection of other tilt sensors to keep itself upright. Only three gyroscopes are needed -- the extra sensors are included as a safety precaution. The Segway has an additional weight sensor built into its platform to tell the computer when a rider has stepped on.
- Brakes: The Segway doesn't have a braking system. To stop, the rider stands upright without leaning forward or backward, and the vehicle maintains its position.
- Turning radius: Since it only has two wheels, the Segway can rotate around a single axis (the wheels turn in opposite directions). This gives the Segway a turning radius of zero.
- Wheels: The Segway wheel consists of a forged steel wheel hub with a glass-reinforced thermoplastic rim. Each wheel is secured to the drive shaft with a single nut. The tires are made of a silica compound, which provides good traction even on wet surfaces.
- Security: The Segway uses an electronic key system. The key, which looks something like a car lighter, stores a 128-bit encrypted digital code. The vehicle won't start unless the key is plugged into its port. The key can also store settings for vehicle operation. Segways include one key for "beginner mode," where the vehicle has a lower maximum speed, and one key for "experienced mode." Segway plans to offer programmable keys down the road, which well let users store particular operation settings.
- Chassis: The Segway's sensitive electronic equipment is housed in a sturdy die-cast aluminum chassis. According to Segway, the chassis can withstand 7 tons of force.
- Control shaft: The aluminum shaft that holds up the Segway's handlebars can be adjusted to different heights. Riders can attach clips to the shaft to carry bags or other cargo.
For information on the development of the Segway and the story of its creator, check out the links on the next page.