A unicycle is a vehicle that touches the ground with only one wheel. The most common variation has a frame with a saddle, and has a pedal-driven direct-drive. A two speed hub is commercially available for faster unicycling. Unicycling is practiced professionally in circuses, by street performers, in festivals, and as a hobby. Unicycles have also been used to create new sports such as unicycle hockey. In recent years, unicycles have also been used in mountain unicycling, an activity similar to mountain biking or trials.
A tricycle, sometimes abbreviated to trike, is a human-powered three-wheeled vehicle.
An electric unicycle is a self-balancing personal transporter with a single wheel. The rider controls speed by leaning forwards or backwards, and steers by twisting or tilting the unit side to side. The self-balancing mechanism uses accelerometers, gyroscopes, and a magnetometer. In 2020, suspension models were introduced by three major manufacturers Begode, Kingsong and Inmotion.
Countersteering is used by single-track vehicle operators, such as cyclists and motorcyclists, to initiate a turn toward a given direction by momentarily steering counter to the desired direction. To negotiate a turn successfully, the combined center of mass of the rider and the single-track vehicle must first be leaned in the direction of the turn, and steering briefly in the opposite direction causes that lean. The rider's action of countersteering is sometimes referred to as "giving a steering command".
A monowheel, or uniwheel, is a one-wheeled single-track vehicle similar to a unicycle.
A Eunicycle is a computer-controlled, partially self-balancing, motorized unicycle invented by Trevor Blackwell. It uses a computer control system similar to the one used by the Segway HT that servos its wheel to balance itself by keeping the contact point of the wheel below the center of mass of the vehicle in the front-to-back direction. To balance from side to side, the rider must rotate the vehicle the same way a unicyclist does, enabling the balancing servo to balance in the new direction.
Wobble, shimmy, tank-slapper, speed wobble, and even death wobble are all words and phrases used to describe a quick (4–10 Hz) oscillation of primarily just the steerable wheel(s) of a vehicle. Initially, the rest of the vehicle remains mostly unaffected, until translated into a vehicle yaw oscillation of increasing amplitude producing loss of control. Vehicles that can experience this oscillation include motorcycles and bicycles, skateboards, and, in theory, any vehicle with a single steering pivot point and a sufficient amount of freedom of the steered wheel, including that which exists on some light aircraft with tricycle gear where instability can occur at speeds of less than 80 km/h (50 mph); this does not include most automobiles. The initial instability occurs mostly at high speed and is similar to that experienced by shopping cart wheels and aircraft landing gear.
A tilting three-wheeler, tilting trike, leaning trike, or even just tilter, is a three-wheeled vehicle and usually a narrow-track vehicle whose body and or wheels tilt in the direction of a turn. Such vehicles can corner without rolling over despite having a narrow axle track because they can balance some or all of the roll moment caused by centripetal acceleration with an opposite roll moment caused by gravity, as bicycles and motorcycles do. This also reduces the lateral acceleration experienced by the rider, which some find more comfortable than the alternative. The narrow profile can result in reduced aerodynamic drag and increased fuel efficiency. These types of vehicles have also been described as "man-wide vehicles" (MWV).
A kick scooter is a human-powered street vehicle with a handlebar, deck, and wheels propelled by a rider pushing off the ground with their leg. Today the most common scooters are made of aluminum, titanium, and steel. Some kick scooters made for younger children have 3 to 4 wheels and are made of plastic and do not fold. High-performance kickbikes are also made.
Bicycle and motorcycle dynamics is the science of the motion of bicycles and motorcycles and their components, due to the forces acting on them. Dynamics falls under a branch of physics known as classical mechanics. Bike motions of interest include balancing, steering, braking, accelerating, suspension activation, and vibration. The study of these motions began in the late 19th century and continues today.
A two-wheeler is a vehicle that runs on two wheels.
A dicycle is a vehicle with two parallel wheels, side by side, unlike single-track vehicles such as motorcycles and bicycles, which have two wheels inline. Originally used to refer to devices with large wheels and pedals, the term is now used in relation to powered self-balancing scooters with smaller wheels and no pedals such as the Segway PT and the self-balancing hoverboard.
Motorcycle components and systems for a motorcycle are engineered, manufactured, and assembled in order to produce motorcycle models with the desired performance, aesthetics, and cost. The key components of modern motorcycles are presented below.
In vehicle acrobatics, a wheelie, or wheelstand, is a vehicle maneuver in which the front wheel or wheels come off the ground due to sufficient torque being applied to the rear wheel or wheels, or rider motion relative to the vehicle. Wheelies are usually associated with bicycles and motorcycles, but can be done with other vehicles such as cars, especially in drag racing and tractor pulling.
The Uno is a novel self-balancing electric motorcycle using two wheels side by side. The Uno III adds a third wheel that allows it to transform into a tricycle.
A scooter is a motorcycle with an underbone or step-through frame, a seat, and a platform for the rider's feet, emphasizing comfort and fuel economy. Elements of scooter design were present in some of the earliest motorcycles, and motor scooters have been made since at least 1914.
The following outline is provided as an overview of and topical guide to bicycles:
Human-powered land vehicles are land vehicles propelled over ground by human power, The main ways to support the weight of a human-powered land vehicle and its contents above the ground are rolling contact; sliding contact; intermittent contact; no contact at all as with anything carried; or some combination of the above. The main methods of using human power to propel a land vehicle are some kind of drivetrain; pushing laterally against the ground with a wheel, skate, or ski that simultaneously moves forward; by pushing against the ground directly with an appendage opposite to the direction of travel; or by propeller. Human-powered land vehicles can be propelled by persons riding in the vehicle or by persons walking or running and not supported by the vehicle.
A narrow-track vehicle is a vehicle that leaves a narrow ground track as it moves forward. Narrow-track vehicles may have lateral stability when stationary but usually lean into turns to prevent falling towards the outside.
