Shifting between gears is a critical function on most modern bicycles (with the exception of single speed and fixed gear bikes), but many riders don't know the difference between the different styles of shifters on the market.
While there are many different styles available, the price ranges are similar. The cheapest shifters can be had for $20 or less and can’t be expected to deliver particularly long life or precision shifting. High-end shifters can cost over $100 (some are over $400) and feature strong, lightweight materials like carbon fiber and magnesium, superior adjustability, and ultra-smooth operation.
This guide will explain some of the fundamental differences between shifters and will help you make a good decision about purchasing a new bike or upgrading an old one.
Trigger (AKA thumb) shifters
The most common shifters on commuter and mountain bikes are called "trigger" or "thumb shifters." This style of shifter is activated when the user presses short levers mounted on the handlebar. Two levers on the left side of the handlebar usually shift up and down through the chainrings on the front of the bike, while the levers on the right shift through the sprockets at the rear of the cycle.
Trigger shifters are lightweight, simple and sometimes display which gear you are in. This design is a solid option for the any mountain biker or casual cyclist.
After trigger shifters, the next most common style is the twist-grip. Twist-grip shifters mount on straight handlebars found on mountain, commuter and casual bikes and are twisted to change gears: twisting them forward shifts in one direction, while twisting towards the rear shifts in the other.
Some mountain bikers prefer twist-grip shifters because of their durability. With no protruding parts, they are hard to damage, even in a high-speed crash. Another nice feature of twist-grip shifters is the ability to display the currently engaged gear using a dial that moves when the gear is changed.
Twist-grips also allow you to multishift (that is, to shift more than one gear with a single motion) more easily than other types of shifters. One major downside of twist-grips is that shifting can occur accidentally if the user is not careful -- if you haven’t used this style before, there can be a small learning curve. Overall, these are a great option for cyclists of all persuasions.
Some bikes, especially older cycles, feature downtube shifters -- levers mounted on the frame of the bicycle rather than the handlebars. This style has some mechanical advantages, chief among them are reduced drag and shorter cable requirements. Downtube shifters also allow your handlebars to be more streamlined.
The biggest downside of downtube shifters is this: in order to change gears, you must ride one-handed for a moment. Because your hands must leave the bar to shift, this style is not recommended for beginners or children; there is a definite learning curve, and this style can be a disadvantage in urban riding or races where shifting must often occur rapidly and at a moment's notice.
Many older bikes -- and some newer models as well -- feature bar-end shifters. This design is mounted on the end of the handlebar of cycles with drop bars (the aerodynamic handlebar style often used on road bikes). Like other designs, shifts are made by moving the two levers up or down, with one lever controlling the front derailleur and the other controlling the rear derailleur.
Bar-end shifters are notably durable, simple, lightweight, and strong, which is why they are a common choice with touring cyclists who put in long days far away from a bike shop. They are also cheap; repairs or replacements can be had for a fraction of the price of more complicated shifters.
Many novice road bikers are confused about how to shift when they first hop on a modern road bike. That is because nearly all modern road bikes use shift levers that are integrated with brake levers, which can conceal them from the untrained eye.
These shifters are called "integrated shifters" and are operated by levers that are adjacent to or integrated into the brake levers, so that pushing the brake sideways (rather than pulling back to engage the brake) engages the mechanism and shifts gears.
Integrated shifters provide excellent performance, with rapid and precise shifting. The rider's hands can also stay in place, which improves safety and handling while shifting.
On the flip side, these designs are more complex and require a bit more maintenance to maintain shifting performance than either bar-end or downtube shifters. They are also more expensive and generally not cross-compatible between brands or across model years.
Despite these small issues, integrated shifters are the norm on road bikes for good reason, and with minor maintenance will provide high quality shifting for years to come.
The newest development in shifter technology is electronically controlled, motor-driven shifting. A traditional shifter is controlled by a cable that pulls a derailleur into position and a spring that returns it; the new electronic models use a motor to do the same thing.
This has a few major advantages. First, because no cable is required to transmit physical force to the derailleur (the movement is provided by a motor), shifting is effortless. Instead of a lever, these shifters work by pressing buttons, which takes lakes energy.
Since these shifters are electronically controlled, they are also self-calibrating and eliminate rubbing issues, over and under shifting, cable stretch issues and dropped chains.
These models are very expensive, and are limited by the battery life (if the juice runs out, you are stuck in whatever gear you were last in!). Luckily, the batteries on popular models last over 600 miles.
The first widely available electronic shifting system (the Dura Ace Di2 from Shimano) was released in 2009. Since then, many other designs have entered the road bike shifter market. These are a great option for serious cyclists seeking the best performance or people who want to eliminate one more maintenance task.