Road bike shifters explained
A road bike shifter is the key mechanism for allowing on-the-move gear changes, this is extremely important when riding varying gradients.
Why are they good?
Shifters are indexed to offer precise shifting, so it eliminates gears slipping or being misaligned. There are still some friction shifters available on the market, but these now only tend to be used for front derailleurs on time trial bikes or very old fashioned bikes with down tube shifters. Indexed shifting works very well on road bikes as it ensures that the bike stays in the required gear even when you are putting out a lot of power up a climb or in a sprint.
What types of shifters are available?
Road bike shifters mostly use a mechanical system that operates by pulling cables to move the derailleurs, which in turn forces the chain to move onto different sprockets/cogs.
Electronic shifting is slowly moving down the price brackets and becoming more popular on road bikes. Electronic shifting works in a similar way to mechanical, but rather than a cable moving the derailleur, an electronic signal is sent which triggers a motor to move the derailleur. The advantage is a more precise change, with no worries about cable stretch.
What brands are best?
There are three main brands to choose from when selecting a road groupset: Shimano, Campagnolo and SRAM. All of the brands combine the gear shifting and brake lever into one clever and neat unit, and usually have a choice of between 9 and 11 speed options (this refers to the amount of sprockets/cogs (cassette) on the rear wheel). All three brands have shifters that look very similar and are positioned in the same place, although the actual function of the shifting leavers differs. Positioning the gear shifters on the handlebar "hoods" is designed to maximise the ease at which both brakes and gears can be used with multiple hand positions on drop handle bars.
This is probably the most common brand of shifters and was also the first to launch an Electronic groupset named Di2. Dual Control or Shimano Total Integration (STI) is Shimano’s name for the integrated brake and gear shifter lever. The Shimano shifter system works by moving the whole brake lever to change gear in one direction, and using a smaller integrated lever inside the main brake lever to change in the other direction.
This Italian brand has an electronic groupset called EPS, as well as a large array of mechanical shifters. “Ergopower controls” is their branding of the integrated gear/brake level design. The Campagnolo system of shifting has a fixed brake lever with a small lever inside this for shifting gear in one direction, then a small button type level on the top of the hoods for changing in the other direction.
This is the final major brand that is competing against Shimano and Campagnolo, and is also the only brand not to currently have an electronic groupset. The SRAM system uses a technology called “DoubleTap”, which means you change up and down by tapping one lever in one direction, but by differing amounts. Their “ErgoDynamic” branding refers to their combined gear and brake levers they use.
How do I choose?
When choosing what brand of shifter would be best for your road bike, it very much depends on the groupset that you use. The groupset you fit to your road bike will limit your shifter options, because Shimano shifters are only really intended to work with Shimano components.
Typically it is not recommended to mix different brands of drive train components, even if they have the same amount of gears. The best way to choose your road bike shifter is to try them both out before purchasing to see which one you find more comfortable, and which lever system you prefer.