Tandem Bicycles

Tandem Bicycles are designed to be ridden by more than one person. In this context, the word 'tandem' describes the seating arrangement. The riders of these bicycles sit behind each other on the bicycle, rather than beside each other.

These bicycles have two sets of cranks, which are linked mechanically to the chain. These cranks turn at the same rate. This creates double the pedaling power in this kind of a bicycle and the tandem bicycle can thus reach very high speeds.

The rider who rides at the front of these bicycles is termed as the 'Captain', 'Pilot', or the 'Steersman', while the rider who rides at the back of the bicycle is termed as the 'Navigator' or the 'Stoker'.

Tandem bicycles have been around for a very long time. Research shows that patents for these bicycles can be found from as early as the 1800s. Earlier versions were built by welding two bicycle frames to each other. Nowadays, however, one finds them with more improved features and designs. They are used in different competitions in the Paralympics for the visually impaired. Visually impaired cyclists ride as stokers while a sighted captain steers the bicycle.

There are different types of tandem bicycles available in the market today. These are generally defined on the basis of the variations in design or usage. There are such bicycles which allow for independent pedaling. For instance, in one type, multiple freewheels can create a situation to allow independent pedaling. Another version or design allows for the front rider to propel the front wheel of the bicycle with his hands and his feet, while the back rider steers and propels the rear wheel with pedals.

There are certain bicycles which have different seating arrangements. There is a version which allows for a child to sit in the front saddle while the adult sits on the rear saddle. The steering is available with extra long handles. Another version allows for the front rider to sit in a recumbent or resting position, while the rear rider sits upright.

Then, there are bicycles which have three wheels. And of course, there are the ones that can seat more than two people at a time. Bicycles are available with seating capacities for 3, 4, and 5 people as well.

Tandem bicycles need to have certain specifically designed parts, so as to ensure their smooth functioning.

These bicycles take on extra weight compared to normal bicycles. Due to this, the wheels need to be designed in a different way. They generally have heavy rims and more spokes. The rear wheels have a wider axle or hub.

Such bicycles have a very specific drive train. The crank for the front rider or captain has a chain ring on the left, while the crank for the rear rider or stoker has chain rings on both sides. The stoker's left side crank is connected to that of the captain which causes the synchronization of the pedal strokes of both the riders. This way the right side of the stoker's side of the frame appears like a standard single person bicycle.

These are the stems and handlebars for the stoker or the rear rider. The handlebars are generally connected to the stem which in turn is clamped around the captain's seat post. Typically, stoker handlebars are shaped like bull horns or they have wide drop bars with pegs instead of brake levers.

A typical rim brake or disk brake can melt on a downhill run due to a variety of reasons, such as overheating, tires melting, warping of the rotor on the disk brake and so on. This is when an Arai drum brake is used. The drum of this brake is screwed on the left side of the tandem hub.

This must, therefore, be threaded for the drum. The shoe plate is slipped over the axle, and the small reaction arm from the shoe plate is engaged with the bicycle frame. This prevents the plate from turning. The drum brake tension is controlled using a friction shifter.

Most tandem bicycles have an eccentric which is located in the bottom bracket shell of the front rider. This is used to adjust the tension of the trimming chain.

Tandem bicycles have gained a large amount of popularity in the UK and the USA due to their unusual style and fashion.