Strengths and weaknesses

180px-TAYLORTRIKETypical upright trikes for adults have front and rear brakes. The front brakes are usually “pull brakes” or V-brakes, and the rear brakes can be pull brakes or internal drum brakes (which operate like automobile drum brakes). Recumbent trikes often brake one wheel with each hand, allowing the rider to brake one side alone to pull the trike in that direction. This has led to a geometry (also called centre point steering) with the kingpin axis intersecting the ground directly ahead of the tyre contact point, producing a normal amount of trail. This arrangement, elsewhere called “zero scrub radius” is used to mitigate the effects of one-sided braking on steering. While zero scrub can reduce steering feel and increase wandering it can also protect novices from spinning out and/or flipping.

The alternative is to use standard Ackermann steering geometry, perhaps with both front brakes operated by the stronger hand. While the KMX Kart stunt trike with this setup allows the rear brake to be operated separately, letting the rider do “bootlegger turns”, the standard setup for most trikes has brakes for each side operated by each hand. Trikes’ strongest suits are cornering, stability, comfort, rider stamina and terminal velocity. Trikes can be used by adults who have problems riding bicyles. As well, trikes are a good choice for elderly riders who are worried about falls. Trikes can ride and climb at very low speed and a kickstand is never needed.

Trikes are always heavier than bikes of the same quality. In fact, the lightest commercially-made tadpole trikes, at around 30 pounds, are easily twice the weight of an upright bicycle of the same cost and quality. Deltas are even heavier. Shortcomings that potential tadpole trikers should realize center on the low riding position which makes them difficult to mount (grab handles are often available) and makes them hard to see in traffic, so flags and blinking lights are often used. Visibility concerns become minimal on bike trails and off-street riding. An often-noted problem with recumbent trikes, much debated by trikers and recumbent riders of all kinds, is their poor climbing ability: the rider cannot get out of the saddle and stand up on the pedals to climb hills. Trikers argue that they make up the time lost going up hills by going much faster on the downhill side because of the low, aerodynamic riding position.

Special purposes

Some tricycles (such as the Christiania and the Pashley load trike) are designed for load carrying. Others are designed for racing or for comfort. Some recumbent tricycles are fully enclosed for all weather use as well as aerodynamic benefits; these are known as velomobiles. Some tricycles, such as the Zigo Leader, are designed to transport children.

Hand & foot trike

With hand and foot trikes, the rider makes a pair of front wheels change directions by shifting the centre of weight and moves forward by rotating the rear wheel. The hand & foot trike can be also converted into a manual tricycle designed to be driven with both hands and both feet[1].
hand & foot trikes

Tandem and hand trikes

Recumbent tandem trikes allow two people to ride in a recumbent position with an extra-strong backbone frame to hold the extra weight. Some allow the “captain” (the rider who steers) and “stoker” (the rider who only pedals) to pedal at different speeds. They are often made with couplers so the frames can be broken down into pieces for easier transport. Manufacturers of recumbent trikes include Greenspeed, WhizWheelz and Inspired Cycle Engineering (ICE). Hand-crank trikes use a hand-operated crank, either as a sole source of power or a double drive with footpower from pedals and hand-power from the hand crank. The hand-power only trikes can be used by individuals who do not have the use of their legs due to a disability or an injury. They are made by companies including Greenspeed, Invacare, Quickie and Druzin.

Children vs adult models

29954955Another way of categorizing tricycles is by whether they are designed for children or adults. Children’s tricycles and most adult tricycles made for the recreational market use the upright layout. From a design point of view, the difference between children’s and adult tricycles is that whereas children’s tricycles are usually direct-drive and have no brakes, adult trikes usually have a gear-drive with multiple speeds and front and rear brakes.
A child rides a steel-framed tricycle in the rain Tricycles are typically used by children between the ages of two and four, after which point they usually switch to a bicycle, often with training wheels. Parents choosing a tricycle for their child should ensure that the trike is not too tall and that the seat is too high, and that the wheelbase is wide enough, because if this is the case, the child may tip over easily.[1] The seat should be stable, which is not always the case with the most inexpensive models. Some trikes have back rests which provide support and a push bar for parents so that the the parents can push the child up hills or hold the child back when descending, or in case of the sudden approach of other traffic.  For safety, children should wear a helmet when riding their trike; some parents may also attach a safety flag to the trike so that the child will be more visible to drivers. A plastic children’s tricycle

Children’s trikes are made of steel frames or plastic. One disadvantage of plastic frames is that they be more likely to tip over than a steel frame if a heavier child is riding. On the plus side, plastic frames will not rust like steel frames if the trike is left out in the rain. A good quality trike’s wheels will have treads, which provide better traction.

While most children’s trike have direct drive, a small number of models such as the Cheetah have chain drive. Unlike adult bikes, children’s trikes do not always have inflatable wheels; instead, some trikes have solid rubber wheels. While this adds to the weight of the tricycle and reduces the shock-absorbing qualities, it eliminates issues with flat tires, punctures, and leaky tubes. Since most trikes are direct drive, the child can slow the trike down by resisting the forward motion of the pedals, as with an adult fixed gear bike. Pull brakes are rarely used on kid’s trikes, but some “Bigwheel”-style plastic trikes have lever brakes in which an inverted half-moon-shaped brake pad is pressed against the driving surface of the righ rear wheel.

Riding

Adults may find upright tricycles difficult to ride because of familiarity with the counter-steering required to balance a bicycle, in which the weight of the body is used during turns. The variation in the camber of the road is the principal difficulty to be overcome once basic tricycle handling is mastered. Recumbent trikes are less affected by camber and, depending on track width and riding position, capable of very fast cornering. A few trikes are designed to tilt into the corners much as a bicycle does, and this also renders them more comfortable on cambered roads. They are referred to as tilting three wheelers (TTW’s). In the case of delta tricycles, the drive is often to just one of the rear wheels, though in some cases both wheels are driven through a differential. A double freewheel, preferably using no-backlash roller clutches, is considered superior. A jackshaft drive permits either single or two-wheel drive. Tadpoles generally use a bicycle’s rear wheel drive and for that reason are usually lighter, cheaper and easier to replace and repair.