Trikes aren't just for kids anymore

Most people in North America learn to ride a bicycle when they're a child. Before they finally discover the thrill of balancing on two wheels without skidding down the pavement on their knees, many go through a phase of riding a tricycle and/or a bicycle with training wheels. The appeal of trikes dies out fairly quickly once bikes are discovered, simply because they are slow and cumbersome in comparison. However, they don't have to be.

Recumbent bicycles have been around since the early 20th century. They were quite quickly found to be faster than conventional upright bikes, and just as quickly they were banned from the racing scene as a result. The conventional upright bicycle took over in popularity because everyone wants something like what the racers have (hence the popularity of 600cc and 1000cc sport bikes for cruising around town). Recumbent bikes never did die out though, and may different configurations of pedal powered vehicles were created over the decades, many of which perform much better than what you see in the Tour de France (most Human Powered Vehicle records are set with fully faired recumbents).



One of the pedal powered vehicle types that is somewhat popular around the world is the recumbent tadpole trike. The reason that I'm writing about this today is that I've recently created one, and have been slowly tweaking it to make it into a useful vehicle. Trikes may not seem all that exciting to most people - they conjure up images of what kids ride around when they're three years old. They do have some advantages over bicycles though: they're accessible to people with balance issues or other disabilities, they can travel very slowly without tipping over, there's no danger of falling over on a slippery patch of ice, etc. That's not to say they're necessarily better than bicycles, as they do have some disadvantages as well in terms of efficiency and maneuverability, they are simply different.

What are the different types?
You may have mentioned I called my trike a "tadpole" trike. This is a reference to the wheel configuration - one wheel in the back, and two in the front. The other popular configuration is called a "delta" trike, which has one wheel in the front and two in the back. Each configuration has they're own characteristics.

Delta trikes are far simpler to build, since they usually have a solid rear axle (no differential usually) and a traditional fork in the front for steering. Some may be built with a large cargo compartment over the rear axle for hauling large, heavy items, making them an alternative to pickup trucks in some countries. While delta trikes are fine at low speeds, they do have a problem with cornering fast. Due to the cornering force being applied from the front and side, they have a tendency to tip over when going fast around a bend. This is why three wheeled all terrain vehicles are no longer produced in North America, having been replaced by Quads.

Tadpole trikes offer the potential for greater performance, at a price of additional mechanical complexity. With the rider sitting between the two front wheels, it takes a much greater cornering force to tip this type of trike over. In fact, a well designed trike will likely exceed its tire traction before tipping, much like a car. The rider is able to be slung very low in front of the rear wheel, which keeps aerodynamic drag low. These types are quite often used for racing. Because the front wheels are individually supported by single sided axles, they require proprietary components to be built, rather than using off the shelf bicycle parts. The front suspension geometry is also fairly important to get right, as improperly setup suspension and steering systems could cause instability at high speeds.

Besides these two basic configurations, there are a wide range of styles. Most trikes are single seaters, but a number have been built to carry a passenger as well, usually in the tandem configuration but occasionally also side by side. An aerodynamic fairing or body could be added to a trike (or bike, for that matter) turning it into a Velomobile - essentially an all weather pedal powered car. The options are endless.

Where do I get one?
Once you've decided what kind of trike suits your needs and desires, you can go out an buy one. There are a number of manufacturers, most of which can be found online. Some brands that come in to my mind are TerraTrike, Catrike, and Icetrikes, though there are many more out there. You may be able to pick one of these up at your Local Bike Shop if you live in a larger city where cycling is popular, but due to their lack of popularity their selection may be limited, or non-existent.

Because these are created in low volume and with proprietary parts, they tend to be somewhat on the pricey side. If you are so inclined, you could also build a trike yourself. One site which offers plans to build your own trikes and bikes is Atomic Zombie. I've never bought anything from there myself (yet!) so I can't speak to the quality, but they are very popular and at first glance their designs seem solid. Perhaps over the winter I may pick up a few plans and try building some of their bikes.