Some components, which are often optional accessories on sports bicycles, are standard features on utility bicycles to enhance their usefulness, comfort, safety and visibility. Mudguards, or fenders, protect the cyclist and moving parts from spray when riding through wet areas and chainguards protect clothes from oil on the chain while preventing clothing from being caught between the chain and crankset teeth. Kick stands keep bicycles upright when parked, and bike locks deter theft. Front-mounted baskets, front or rear luggage carriers or racks, and panniers mounted above either or both wheels can be used to carry equipment or cargo. Pegs can be fastened to one, or both of the wheel hubs to either help the rider perform certain tricks, or allow a place for extra riders to stand, or rest. Parents sometimes add rear-mounted child seats, an auxiliary saddle fitted to the crossbar, or both to transport children. Training wheels are sometimes used when learning to ride.
No endorsement is required on a driver license in order to operate a motorized bicycle, thus the motorized bicycle may be operated by anyone with a valid driver license. Goggles, windshields and other special equipment required for motorcycles and motor-driver cycles are not required for operation of a motorized bicycle. However, crash helmets are required regardless of operators age. Minors between the ages of 14 and 16 may apply for a restricted license to operate a motorized bicycle, just as they would to operate a motor-driver cycle. For instance, they must take a written test, vision tests and demonstrate their ability to operate the motorized bicycle. The license issued will be restricted to a motorized bicycle only. The license is valid only during daylight hours and within a seven-mile (11 km) radius of the driver's home. Applicants for any type of license less than eighteen (18) years old, must complete a Minor/Teen-age Affidavit and Cancellation form making the parent or legal guardian financially liable for the applicants action. 
The two most common types of hub motors used in electric bicycles are brushed and brushless. Many configurations are available, varying in cost and complexity; direct-drive and geared motor units are both used. An electric power-assist system may be added to almost any pedal cycle using chain drive, belt drive, hub motors or friction drive. BLDC hub motors are a common modern design. The motor is built into the wheel hub itself, and the stator fixed solidly to the axle, and the magnets attached to and rotating with the wheel. The bicycle wheel hub is the motor. The power levels of motors used are influenced by available legal categories and are often, but not always limited to under 750 watts.
Oregon Law (ORS 801.258]) defines an electric assisted bicycle as an electric motor-driven vehicle equipped with operable pedals, a seat or saddle for the rider, no more than three wheels in contact during travel. In addition, the vehicle must be equipped with an electric motor that is capable of applying a power output of no greater than 1,000 watts, and that is incapable of propelling the vehicle at a speed greater than 20 miles per hour on level ground.
The entire drive system is neatly incorporated into the bike's design for optimal weight distribution and the ultimate in sexy design, while users control torque and power output, which peaks at a surprisingly punchy 530W, via a cool Mission Control App that can also be programmed to a time or distance parameter to ensure there's enough power to get you home.
With hand-operated brakes, force is applied to brake levers mounted on the handlebars and transmitted via Bowden cables or hydraulic lines to the friction pads, which apply pressure to the braking surface, causing friction which slows the bicycle down. A rear hub brake may be either hand-operated or pedal-actuated, as in the back pedal coaster brakes which were popular in North America until the 1960s.
"Electric-assisted bicycle" means a bicycle with two or three wheels, a saddle, fully operative pedals for human propulsion, and an electric motor. The electric-assisted bicycle's electric motor must have a power output of no more than one thousand watts, be incapable of propelling the device at a speed of more than twenty miles per hour on level ground, and be incapable of further increasing the speed of the device when human power alone is used to propel the device beyond twenty miles per hour.
Like most electric bikes, the Rad Wagon is also fairly heavy, weighing 72 pounds. The last drawback is that it comes in only one frame size (which I imagine helps to keep costs lower) that fits rider heights between 5 foot 2 inches and 6 foot 2 inches. My 6 foot 4 husband, however, can ride the bike just fine, so there’s some wiggle room to this range.
Electric-assisted bicycles are treated as human-powered bicycles, while bicycles capable of propulsion by electric power alone face additional registration and regulatory requirements as mopeds. Requirements include electric power generation by a motor that cannot be easily modified, along with a power assist mechanism that operates safely and smoothly. In December 2008, The assist ratio was updated as follow: