Gears

 

A potted history of bicycle gears

For a long time, the bicycle had one gear. This used a single sprocket fixed to the rear wheel hub. This is what is known as ‘fixed gear’, meaning that whenever the bike is moving, the pedals turn.

fixie cog_576p

A fixed gear sprocket


The industry’s first innovation was to attach a ratchet to that sprocket so the bike could coast down hills. This ratcheted sprocket was named the freewheel. To differentiate this single speed freewheel drive train from the more complex multi-speed drive trains that were subsequently invented, people now use the term ‘single speed’.

villiers freewheel576p

A single speed freewheel

The next innovation was the multi-speed hub, designed by the English firm Sturmey Archer in the early 1900s, which allowed the cyclist to select one of three gears: a low one for going up hills, a normal gear for the flat and high one for descents. The ability to select gears was seen as a leap forward in bicycle technology, as this advert from 1913 shows. Although the idea of a multi-speed bicycle was initially frowned upon by purists who thought it made cycling too easy, the Sturmey Archer hub gear is still manufactured today and its design remains fundamentally unchanged.

The next invention provided an alternative to the hub gear. The single speed freewheel was replaced with a cluster of differently sized sprockets. The inventors used the small amount of sideways movement in a bicycle chain to shift the chain between sprockets, and used a sprung mechanism to take up the slack. This became known as the derailleur system. It was lighter and more versatile than the hub gear, since the user could select the exact gear ratios – qualities that endeared it to the riders in the Tours de France – and, in the 1970s, to people with ‘racer bikes’. It was the natural choice, in the 1980s, for the new cycle sport of mountain biking.

Comparing single speed, hub gear and derailleur

Fixed, single speed, hub gear and derailleur systems are all useful for transport cycling. Which type of gear best suits your needs depends on your local terrain (i.e. how hilly it is), your fitness level and your ability to carry out occasional maintenance (or your access to someone who can adjust bike gears for you). Some of these gear systems are harder-wearing than others, although wear depends how well they are set up and maintained.

Here is an analysis of each system in turn, starting with single speed. For each system, we’ll consider terrain, rider fitness, maintenance, wear and servicing.

NB Here we’re talking about gear systems priced at £500 or less. More expensive hub gear systems exist which overcome some of these limitations.

 

Single speed

Terrain: best suited to cycling on flat terrain, not hills

Fitness: a relatively high fitness level is required because the rider cannot change gear to making pedaling easier – unless a particularly large sprocket is installed

Maintenance: an extremely low maintenance system that does not require adjustment

Wear: extremely hard wearing

Servicing: the system is so resilient, it needs virtually no servicing

 

Hub gear

Terrain: suited to cycling on the flat and on gentle hills

Fitness: a moderate fitness level is required and the gear is only variable within a certain range

Maintenance: a low maintenance system if set up correctly

Wear: reasonably hard wearing, though occasional servicing is necessary

Servicing: a complex job for an experienced mechanic

 

Derailleur

Terrain: suited to all terrain, from cycling on the flat to steep hills

Fitness: suitable for riders of any fitness level

Maintenance: a high maintenance system requiring regular cleaning and lubrication and periodic adjustment to keep it working properly

Wear: not hard wearing; parts require replacement from time to time

Servicing: a relatively simple task that can be done by the user at home

 

Comparison table

System
Terrain Fitness Maintenance Wear Servicing
Single speed flat high very low hard wearing not required
Hub gear flat, gentle hills moderate low mid wearing difficult
Derailleur flat, any hills any high soft wearing simple

 

More articles on gear systems

For more information on the different gear systems, follow these links: