Trike motorcycles (or Trikes for short) are custom made vehicles based upon motorcycles.
Although you can get them based on scooters (where you'd sit in an upright position with 'step through/knees together' positioning) they are more commonly associated with a straddle sitting back position.
Although some manufacturers produce trikes in small numbers they are almost exclusively still custom vehicles due to lack of demand. Manufacturers of trikes include Piaggio Ape, Can-Am, T-Rex and Bombardier Recreational Vehicles.
Motor trikes are attractive for those with mobility problems (as they are easy to get in and out of) or want to carry passengers with a motorcycle license. You also do need need to wear a motorbike helmet with them.
Different Trike Motorcycle Configurations
Trikes (like a lot of 3 wheeled vehicles) can be difficult to define. A motorcycle with sidecar is not considered a trike as it can easily be turned back into a 2 wheel motorcycle.
The most regular design is to have 1 wheel at the front (controlled by motorcycle forks) and 2 at the back, driven by the engine. This configuration is called Delta and has a very stable footprint on the ground, however they can be difficult (as in large turning circle) to turn due to the configuration.
Reverse design trikes are also available (2 wheels at the front, 1 at
the back) however this are much hard to engineer and can be difficult to
control with less rubber to put the power through and twice as much
resistance to turn the front). These are often known as Tadpole design and are usually chosen for uniqueness (even more so than a delta trike). Occasionally rear wheel steering is used for this design. Due to extra wheels on the front, tadpoles are more stable under braking and can give a more go-kart feel to the handling.
Disadvantages of a Trike Motorcycle
Out in the weather - The most notable and obvious disadvantage of a motorcycle applies to trikes too. You will be out in the weather and that means rain, direct sunlight and possibly snow. An advantage over motorcycles is you can add a roof over the top, although this can compromise the style.
Width - Whilst not quite as wide as modern cars (in most cases) trikes have a disadvantage over motorcycles in width. This means it's more difficult to overtake and virtually impossible to filter through traffic like a motorcycle can too leading to much frustration when you see a fellow rider go past!
Benefits of a Trike Motorcycle
Out in the open - Just like a motorbike, you get the feeling of being 'on' a vehicle rather than 'in'. The feeling of freedom are much more intense than a car and you can experience the environment more.
No need to wear a motorcycle helmet - Trikes aren't susceptible to the same laws as motorcycles so most states and countries do not require a helmet to be worn, this also amplifies the out in the open aspect as above, yet is not so necessary as trikes are more stable and you are unlikely to require a helmet in one any more than a car driver.
More seating - Trikes can have 1-4 seats, so you can take the kids out on it! (Or should this be in disadvantages...).
Flexibility in Licence required - You can ride a trike with a car or motorcycle licence. Although the controls will be more familiar to a motorcycle rider (such as forks controlling the front wheel rather than a steering wheel).
Unique - Whilst you won't be the only one of the road with the trike, you are highly unlikely to see another one about. They also have more body design options to create something unique to you and custom on a level motorcycle riders dream of.