bike - Folding bicycle
Photograph by Thirteen Of Clubson Flickr.
A folding bicycle incorporates special design features enabling the bike to fold into a compact bike Touring bicycle form, thereby facilitating transport or storage. Other public transportion systems may ban or restrict other bicycles, or may require that folding bicycles be enclosed in bags or covers to protect other passengers.
People who live in a small apartment often prefer a folder as it can be more conveniently stored indoors than a full-sized bicycle. As folded bikes require less space, they are allowed by some public transporation systems, e.g.,Transport for London, which allows folding bikes to be carried at any time on buses and Underground lines. This system is operated by a single quick release found along the top tube of the bike. Folding bicycles are particularly suitable for urban commuters.
The bicycle was used by British paratroopers at the D-Day landings and at the Battle of Arnhem. Intended for commuter and utility purposes, folding bikes emphasize ruggedness, comfort and convenience â€” though there are high-end models that emphasize speed. Design constraints that enable the bikes to fold, such as small wheels and a shorter wheelbase may give a more rough, twitchy ride. A folding bicycle was developed as a small size was needed to enable it to be taken on parachute jumps from aircraft.
When folded, the bikes can be more easily carried into buildings, into workplace or onto public transportation (facilitating mixed-mode commuting) â€” or more easily stored in compact living quarters or aboard cars, boats or airplanes. The iXi literally breaks into 2 halves.
Mixed-mode commuters who deploy the fold mechanism several times daily for portage aboard public transport may prioritize a bike with an easy, quick fold. Swing and flip hinges may be combined on the same frame, as in Brompton and Dahon, which use a folding steering column.
The Giatex folds and retracts, adjusting to the size of the rider. Airline baggage regulations may permit folding bikes as ordinary luggage, without extra cost. .
To compensate, folders may feature increased weight as well as more substantial or additional frame members. Folding bikes generally come with a wider range of adjustments than conventional bikes for accommodating different riders, because the frames are usually only made in one size. Regardless of how each folds, the result is easier to transport and store than a traditional bicycle. Folding mechanisms are highly variable. Half or mid fold Many folding frames follow classic frame pattern of the safety bicycle s diamond frame, but feature a hinge point (with single or double hinges) allowing the bicycle to fold approximately in half.
Marine users, seeking a bike for incidental shore mobility, may prioritize the compactness of the folded bike. The step-through design is a boon to a wider range of rider size, age and physical ability.
Some manufacturers are producing folding bikes designed around folding systems that allow them to utilize 26 wheels, e.g. Seatposts and handlebar stems on folders extend as much as four times higher than conventional bikes.
They often fold near the frame mid-point (which may weaken or flex) or have elongated seatposts and stems which may experience greater bending stresses. 24 inch wheels are the largest for which flip hinges are generally used, but smaller wheels, typically 16 or 20 inches, are more common.
While folding bicycles are usually smaller in overall size than conventional bicycles, the distances between center of bottom bracket, the top of the saddle and the handlebars, the primary factors in determining whether a bicycle fits its rider, are usually similar to that of conventional bikes. The wheelbase of many folding designs is also very similar to that of conventional, non-folding, bicycles.
Riders using their bikes less frequently may prioritize speed and comfort of ride over ease and quickness of folding. Covers range from custom made bags, to bin-liners and shopping bags for smaller folders.
It allows the user to fold the bike without breaking any vital tubes down, preserving the structural integrity of the diamond frame. For even greater range of adjustment, longer after-market posts and stems are available.
Another system found on folders such as Montague Bikes utilizes the seat tube as a pivot point for the frame to fold. Folding mechanisms typically involve latches and quick releases, which affect the speed of the fold/unfold.
The Strida has a triangular frame and folds to resemble a unicycle. Folding mechanisms may incur more cost and weight, allow folding smaller, and tend to use smaller wheels. Some may restrict folding bikes to off rush-hour periods.
They forgo the performance and easy ride benefits of their larger counterparts, acquiring characteristics similar to those of an adult folding kick scooter. Other variations include the bicycle torque coupling is a proprietary connector system that can be retrofitted to a standard frame.
the Montague Corporation. The A-bike is similar to the Strida but has tiny wheels and compacts a bit smaller. This system uses a tube within a tube design to give the bike more torsional stiffness.
Bikes smaller than a Brompton are often called portable bicycles. A similar swing hinge may be combined with a folding steering column.
The folding mechanisms themselves are highly variable, with each design offering a unique combination of folding speed, folding ease, compactness, engineering, ride, weight, durability and price. Distinguished by the complexities of their folding mechanism, more demanding structural requirements, greater number of parts, and more specialized market appeal, folding bikes may be more expensive than comparable non-folding models. Sometimes categorized as folding bicycles, another group of bikes (also called break-away models) may separate into pieces rather than fold. Military interest in bicycles arose in the 1890s, and the French Army and others deployed folding bikes for bicycle infantry use. The British WWII Airborne BSA Folding Bicycle was used from 1939-1945 in the Second World War by British paratroopers. Smaller size does not mean lighter weight, as most of these designs forgo the bracing benefits of the diamond frame, and must compensate as a step-through frame does, with thicker metal.
To compensate, folders feature wider tires and may offer front or rear suspension. Folding bicycles present challenging structural compromises. Bike Friday offers a model, the Tikit, featuring a cable-activated folding mechanism requiring no quick releases or latches, for increased folding speed. Break away and other styles Bikes may partly fold and partly disassemble for packing into a standard or custom sized suitcase for air travel (e.g., Airnimal and Bike Friday).
The Gekko folds from the seat tube like an upside down umbrella. Such a flip hinge may be combined with a folding front fork as in the Birdy.