A small-wheel bicycle, sometimes called a mini velo or mini-velo, is an adult

bicycle A bicycle, also called a pedal cycle, bike, push-bike or cycle, is a human-powered transport, human-powered or motorized bicycle, motor-assisted, bicycle pedal, pedal-driven, single-track vehicle, with two bicycle wheel, wheels attached to a ...

with a reasonable sized frame and relatively small

wheels A wheel is a rotating component (typically circular in shape) that is intended to turn on an axle bearing. The wheel is one of the key components of the wheel and axle which is one of the six simple machines. Wheels, in conjunction with axl ...

, usually of ETRTO 406 mm (20") or less nominal diameter, which is smaller than the common 622 mm (700c)

road bicycle The term road bicycle is used to describe bicycles built for traveling at speed on paved roads. Some sources use the term to mean racing bicycle. Other sources specifically exclude racing bicycles from the definition, using the term to mean a ...

wheel size or 622 mm, 584 mm or 559 mm (29, 27.5 or 26")

gravel Gravel () is a loose aggregation of rock fragments. Gravel occurs naturally on Earth as a result of sedimentation, sedimentary and erosion, erosive geological processes; it is also produced in large quantities commercially as crushed stone. Gr ...

and

mountain bike A mountain bike (MTB) or mountain bicycle is a bicycle designed for off-road cycling (''mountain biking''). Mountain bikes share some similarities with other bicycles, but incorporate features designed to enhance durability and performance in r ...

wheel sizes common on most full-sized adult bikes. They can be folding or non-folding. While many

folding bicycle A folding bicycle is designed to be compacted into a smaller, more manageable size or shape, making it easier to store or carry . When folded, the bikes can be more easily carried into buildings, on public transportation (facilitating mixed-mo ...

s are small-wheel bicycles, not all small-wheel bicycles can fold. Some small-wheel bicycles neither fold nor separate, such as the Moulton, which comes in both fixed-frame and separable-frame versions. While

BMX bike A BMX bike is a bicycle used for cycle sport, specifically racing or stunt riding. BMX stands for ''bicycle motocross''. Construction Though originally denoting a bicycle intended for BMX racing, the term "BMX bike" is now used as a generic ...

s also have ETRTO 406 mm ("20 inch") wheels, they are not normally categorised as "small-wheel bikes".

History

An early proponent of small-wheeled adult bicycles was

Paul de Vivie Paul de Vivie, who wrote as Vélocio
(28 April 1853

, better known by his pen name "Vélocio". His approach was to use a balloon-width

tire A tire (North American English) or tyre (Commonwealth English) is a ring-shaped component that surrounds a Rim (wheel), wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide Traction (engineeri ...

of about 57 mm (2.25″) on a 500 mm (20″) rim, giving a wheel of approximately 600 mm (24″) in diameter.De Vivie, P. (writing as "Vélocio"), ''Le Cycliste'', France, 1911. (French original provided by Raymond Henry. English translation commissioned by Tony Hadland.) 1965 moulton drive side bootiebike

The man credited with being the father of modern small-wheel bicycles is

Alex Moulton Alexander Eric Moulton (9 April 1920 – 9 December 2012) was an English engineer and inventor, specialising in Suspension (vehicle), suspension design. Early life and education Moulton's father, John Coney Moulton, was a naturalist working in ...

who pioneered the field with his F-framed Moulton Bicycle in 1962. His original small-wheeled design notably featured full suspension. Raleigh introduced the RSW-16 as a direct competitor, but it lacked the suspension of the Moulton and compensated for this by using very wide 50 mm (2-inch) "balloon" tires. The RSW-16 "Compact" was a folding version. In 1968 Raleigh introduced the Raleigh Twenty, which later went on to become one of Raleigh's biggest sellers. A large number of European manufacturers made U-frame small-wheeled and folding bicycles in the 1970s.

Advantages and disadvantages

Smaller wheels are more maneuverable. For this reason, and in some cases for comic effect, they are used in some clown bicycles. Smaller wheels more faithfully follow the terrain, giving a harsher ride on bumpy roads that are effectively smoothed by larger ones. It may be desirable for bicycles with smaller wheels to also be fitted with some form of suspension to improve riding characteristics. Bicycles with small wheels normally have their gearing adjusted to provide the same effective wheel radius as large ones, so pedalling cadence is not different. Smaller wheels tend to weigh less than larger ones, thus bringing the performance benefits of light wheels. Small wheels, all else being equal, have slightly higher

rolling resistance Rolling resistance, sometimes called rolling friction or rolling drag, is the force resisting the Motion (physics), motion when a body (such as a ball, tire, or wheel) Rolling, rolls on a surface. It is mainly caused by Plasticity (physics), non- ...

. On the other hand, they have lower

aerodynamic drag In fluid dynamics, drag, sometimes referred to as fluid resistance, is a force acting opposite to the direction of motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers, two solid surfaces, or b ...

due to their smaller area, which is proportional to their radius.

Length reduction

The overall length reduction of a bicycle using smaller wheels depends on several factors, but mainly the wheel size and whether the

wheelbase In both road and rail vehicles, the wheelbase is the horizontal distance between the centers of the front and rear wheels. For road vehicles with more than two axles (e.g. some trucks), the wheelbase is the distance between the steering (front ...

(distance between the front and rear axles) is reduced. For example, keeping the same axle distance, and going from a 40-622 wheel (approx. 702 mm diameter) to a 30-406 wheel (approx. 466 mm diameter) will result in an overall length reduction of 236 mm. Theoretically that reduction may be doubled if bringing the wheels closer together by shortening the axle distance. However, a shorter wheelbase may result in twitchiness or poor stability.

References

External links

Usenet quote: "A larger wheel rides better on average roads and always corners better because it brings a longer contact patch to the road."
Mechanical engineer Jobst Brandt on optimal wheel sizes {{Human-powered vehicles Small wheel bicycles Small wheel bicycle

History

Advantages and disadvantages

Length reduction

See also

Notable models

References

External links