Let’s face it, one of the biggest stand out features of today’s bikes compared to those of yesteryear are the new-age components that are so precise and accurate. The chainset, the gear levers, the derailleurs, the brakes, and the bottom bracket – the groupset or the ‘gruppo’ is what is responsible for churning pedal power into forward motion.


A bike’s groupset is essentially a collection of components on your bike that aid in driving or stopping the wheels. These components are often not made by bicycle manufacturers themselves. Instead, they are made by groupset specific manufacturers such as Shimano, SRAM, and Campagnolo, each of who have driven the development of cycling for many decades. 


  1. Shifters
  2. Chainset
  3. Cassette
  4. Derailleurs
  5. Brakes
  6. Bottom bracket
  7. Chain


Shifters are essentially your one-way communication with your front & rear derailleurs.

Depending on your bike, shifters are available as thumb switches (MTB), lever mechanisms (Road), or the now extinct grip shifters, that help you select the gear that best suits the terrain.


The chainset also referred to as the crankset is the large, toothed set of “chainrings” that are spun by the pedals. A triple chainset uses three rings (3X, or “three by”), a double uses two (2X), and a single – of course – is just the one ring (1X). Triple chainsets have become less common, especially on mountain bikes and high-end road groupsets.

Shimano’s SLX chainset

New age bikes usually have have either a two-by(2X) or a one-by(1X).


The Cassette is the cluster of cogs/sprockets that most folk simply refer to as “gears”. Each sprocket contains a different number of teeth, requiring a different degree of torque to spin the rear wheel.

Teeth numbers range anywhere from nine to 51, and a cassette is usually described by stating its smallest and largest sprocket, i.e 10-50, for example. This along with the capacity of your chainset is how most manufacturers refer to the bike’s overall “gearing capacity”. For example, a bike with two chainrings on the crankset and 10 sprockets at the back will be referred to as a 2X10 bike.


These are the components responsible for physically moving your bike’s chain from one chainring/cog to another.

The front derailleur (or FD) sits above the main chainring. It’s a mechanical cage like arm, controlled by the shifters, that moves the chain from one chainring to the other.

The rear derailleur (or RD) is attached to the rear of the bike’s frame (usually via a component called a “hanger”). Similar to the front derailleur, it moves the chain across the rear sprocket when activated by the shifters.


The brakes are one of the most important components in your drivetrain. They are responsible for slowing you down when you are moving. They, just like the other components in a groupset, improve in quality as you move up the brand hierarchy. 

Brakes come as traditional calipers (mostly road) or the increasingly popular disc-brake format (mostly MTB).


The bottom bracket is a little complicated to understand – think of it as a large axle through which the pedals are connected, and around which they rotate. 

This seemingly unimportant component is the bearing through which there is a connection between the crankset and the bike’s frame. Quality in this vital junction is paramount for efficient power transfer. A good-quality unit, if correctly installed, should provide years of trouble-free riding, but bearings can and do wear out over time.

The bottom bracket is an unexpectedly complex part of the groupset and its intricacies are best explored in our other article: BEGINNERS GUIDE TO BOTTOM BRACKETS


The chain is a combination of very small intricate parts – links, pins and plates. These tiny components together form a lengthy chain.

Chains come in different lengths to suit different gearing options on bikes. For example, an 11-speed gear set-up has larger sprockets and requires more links.

Sprocket widths are also important, with more compact cassettes requiring more slender fitting chains. Higher quality chains are lighter, last longer, and less likely to snap under pressure.



Road bikes are meant to go fast and go the distance. Which is why road groupsets have one main purpose in mind – PERFORMANCE.

Road groupset designers have turned their attention to creating lean, clean, and obscenely fast-shifting machines. Road groupsets have tighter gear ratios for smoother gear changes and lower cadence fluctuations. Lighter cassettes and cranksets for an overall snappier feel when you need to put down some serious power. Road groupsets have super tight tolerances too – 11 and 12-speed bikes are a common sight these days.

Road bikes will also generally have large chainrings on the crankset – typically 52 or 50 teeth on the big ring and 39 or 34 on the small. Mountain bike double chainrings on the other hand will more often be in the low 40s for the large and low 30s on the small to aid steep hill climbing and acceleration.

The rear cassette is often small in comparison to MTBs too. Again, this is for maximizing speed on the flats.


MTB groupsets are similar in functionality but where they differ is in their purpose specific builds.

One of the first things you’ll notice is the weight and robustness. Road bike groupsets, especially at the top of the hierarchies, are designed for pure speed, using the lightest weight materials available (such as carbon fiber). Mountain bike drivetrains on the other hand, are built to withstand impact and put reliability at the top.

MTB groupsets tend to lack the finesse of road components and instead are designed to be tougher and more rugged to handle the rigors of off-road usage along with an expected level of abuse.

As for the gearing, you will notice that MTBs usually really big cassettes. This is done to make up for the smaller chainrings. Most MTBs these days have two or only one chainring in the front.


All manufacturers have a certain hierarchy that their groupsets follow. From from entry level to professional, they vary widely in price, but what do you get for that additional money?

It’s rather simple – as you move through the hierarchy levels, you’ll find better-machined parts, more accuracy in shifting, smoother operation, and reduced weight. you’ll also find more gradual gear ratios and elements like 11-speed cassettes instead of nine or ten. The hierarchy exists simply in order to provide the consumer with more choice.

When looking at a new bicycle, don’t worry too much about the groupset. As you get more competitive on the road/trail, or you find yourself pushing the limits of your bike, you may reach a point where your groupset is not able to keep up with you. This is when you may want to consider upgrading.

A fresh groupset overhaul is a great idea after a couple of years of riding especially if you’re already on a solid and correctly sized frame. But remember, apart from chains, most other groupset components are not inter-brand compatible. It’s better to stick to one specific manufacturer.

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About the Author

Shaun George

WHAT I LOVE ABOUT CYCLING I'm an avid mountain biker and I like riding fast and flowy singletrack. As I keep riding, I continuously work on honing my riding skills. I like to ride whenever possible, especially with friends. I also like to influence folk into getting to ride more often. Working on bicycles has also been a keen interest of mine for quite some time. DISCIPLINE: Mountain biking and Road biking CURRENT BIKE: Merida One Twenty 9.600 & Specialized Allez Elite DSW DREAM BIKE: Santa Cruz 5010

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