What is a road bike groupset? And what should you look for in the key components that make one up?
What is a groupset?
On bikes, the term groupset, or “gruppo”, refers to any mechanical or electronic parts that are involved in braking, changing gear, or the running of the drivetrain. That means the shifters, brake levers, front and rear brake calipers, front and rear derailleurs, crankset, bottom bracket, chain, and cassette.
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If you’re buying a bike, then, after the frame, the groupset is the second thing that you should look at, and is a key determining factor in working out whether the bike in front of you offers good value for money or not.
There are three main manufacturers of groupsets and bike components. Shimano is the largest and best known, while the other two of the “big three” are Campagnolo and SRAM. All three manufacturers offer a range of groupsets at competing price points.
Components of a road bike groupset
The shifters on a road bike are used change gear. Shimano’s STI (Shimano Total Integration) shifters are the most common design. The brake lever can be pushed inwards (sideways) to change up into an easier gear. To change down, there is a second lever behind the first that can be separately pushed inwards. To apply the brake, both levers are pulled backwards, towards the rider.
With shifters from Campagnolo and SRAM you brake in the same way but shift slightly differently. With Campag you shift down using a shifter behind the brake lever, and change up using a thumb shifter on the inside of the hoods.
On mechanical SRAM groupsets, you shift up by pushing the lever in one notch, and change down by continuing to push it in slightly further. However with SRAM Red eTap, the American company’s electronic groupset, you shift up at the back by pressing the right shifter, down at the back by pushing the left shifter, and push both simultaneously to shift the front derailleur.
The most common brakes found on road bikes are cable-operated calipers that engage with the wheel rim. Recent advances have seen the introduction of hydraulic calipers, although these are not widely used, and an increasing number of road bikes are being equipped with disc brakes.
Disc brakes are now UCI-legal (meaning they can’t be ridden in UCI road races) – yet surrounded by much controversy after riders have claimed cuts and lacerations have been caused by the rotors. For those riding outside of the peloton, but they can offer much improved braking power and modulation. In addition, because the wheel rim does not have to be reinforced to feature a braking surface, the rim can be lighter. Direct-mount calipers are also being seen in increasing numbers and offer superior performance to single mount calipers, but they are only compatible with specific frames.
Chainsets housing the front gears can be split into two main categories – doubles and triples. A double has two chainrings while a triple has (you guessed it) three.
Double chainsets are available in different ratios, with 53/39t being the standard combination favoured by road racers (for those new to cycling, the numbers refer to the number of teeth on the chainring and the bigger number, the bigger the gear. A bigger front gear is harder to push but can achieve higher speeds).
Compact chainsets have a 50/34t ratio and are currently the most common gearing equipped on road bikes. The smaller 34-tooth chainring makes this kind of chainset ideal for riding in hilly terrain. A third, increasingly common ratio known as mid-compact, with a 52/36 ratio, is also available, and is good if you want to be able to push a big gear down fast descents, but also want a small inner ring to fall back on in the hills.
Triple chainsets are being used less frequently these days, but they are often found on touring bikes as they offer the greatest range of gears, which is useful when riding a bike laden down with heavy kit. The most common ratio is 50/39/30t.
The chainset also features the cranks, which attach to the pedals. The length of the crank arms can vary, typically ranging from 160mm to 180mm. The length of the cranks that come fitted to a complete bike is usually related to its size — for example, a 56cm frame will often have 172.5mm cranks. Longer cranks offer a bigger mechanical advantage and larger effective gear, but can be harder to turn. Shorter cranks are sometimes favoured in criteriums, as they offer more ground clearance to let you pedal around corners.
The cassette refers to the collection of sprockets on the rear wheel. These are available in wide range of different ratios. An 11-speed cassette will have 11 sprockets on the cassette, which can be arranged in a close ratio such as 11-23t, which will be good for time trialling and racing on flatter terrain, as the close gears allow for fine adjustment and very smooth shifting, or a wider ratio like 11-32t, which gives you more gears to choose from when riding in hilly terrain.
You can change your cassette and it is common for cyclists to own a few different ratios. However it is important to remember that the size of the biggest ring on a cassette is limited by the length of the cage on the rear derailleur, so check with your local bike shop before you splash out on that 32-tooth granny gear!
The type of chain is dependant on the range of gears, i.e. a 10-speed groupset requires a 10-speed chain. An 8-speed chain is considerably wider than an 11-speed chain. More expensive chains feature alloy coatings that are more resistant to wear, and are often lighter. Chains, like cassettes, wear over time, so will need to be replaced periodically.
The derailleurs (also called mechs) are responsible for guiding the chain from one sprocket to the next. A cable is usually responsible for the shifting, but electronic groupsets, such as Shimano Ultegra Di2, SRAM Red eTap, or Campagnolo EPS, use small motors to move the derailleur. Front derailleurs are either band on, or braze on, so make sure you select the correct option if purchasing separately from your frame. Band on refers to a circular clamp to attach to the frame. This is not always possible, as bike frames are not always round. To counter this, braze on derailleurs are riveted or bolted to the frame. The more expensive rear derailleurs feature ceramic bearings in the jockey wheels.
Electronic vs mechanical shifting
If you’ve got more than £3,000 to spend on a new bike then you will likely be faced with a choice of whether to go for electronic or mechanical shifting. Which you choose to go for depends really upon what you’re priorities are and the sort of riding you do.
For out and out performance, electronic groupsets are the natural choice, as shown by the fact that all but a handful of riders in the professional peloton now choose to use it thanks to the slightly sharper shifting and the ability to shift through multiple gears at once. And don’t be put off by the fact that the batteries have to be recharged (once in a blue moon) or the idea that it might be susceptible to the elements (in fact we’d argue that gear cables are much more vulnerable to wet and muddy roads and electronic wires).
Of course there are still many benefits to mechanical groupsets. The shifting on most mechanical groupsets is still very good, and if something goes seriously wrong then it’s much easier to be fixed than electronic. But perhaps most importantly, it’s also considerably cheaper, with the Shimano Dura-Ace Di2 costing £1,000 more than standard Dura-Ace, while Campagnolo Super Record is a massive £1,200 dearer.
What do you get for your money when buying a road bike groupset?
Groupsets vary in price a great deal, but what changes as the price goes up? The first thing to consider is weight. A lighter bike will accelerate faster and climb quicker than a heavy one, but components also need to be strong and stiff. As the price of components increases the weight decreases. In order to maintain strength, durability and stiffness of the lighter components, more expensive materials are required. For example, an entry level groupset will likely have a steel chain, with a top end groupset featuring a titanium chain.
Manufacturing tolerances are much more higher on a top end groupset, which means that with an increased price, you get improved shifting between gears. More expensive components are smoother, more precise and quicker to shift. Electronic groupsets are currently the benchmark in shifting performance, offering smoother shifting when changing gear under load, such as when riding out of the saddle or grinding up a hill. In these situations the lower end groupsets will be very clunky and strained, whereas the electronic shifting is sublime.
Something to consider is that the shifting performance does tend to level out for the top two tiers. For example, the shifting quality between Ultegra and Dura-Ace is very similar, and the difference between the two primarily comes down to weight.
Braking performance also improves as the price goes up, with the calipers becoming stiffer up the hierarchy. This translates to more power, feel and modulation. The more expensive chainsets tend to be lighter and stiffer too. This can transform a bike, as a stiff crankset is more efficient at transferring the power from the pedals into forward motion. A chainring that flexes slightly under load will absorb energy, and decrease shifting performance too. For these reasons the big sprinters, such as Marcel Kittel will favour very stiff chainsets.
As one would expect, durability generally improves as you move up in price. Quality mid-tier components such as shifters and derailleurs last a very long time if properly maintained. However it is important to consider that the top-tier groupsets, such as Super Record and Dura-Ace, are not designed for workhorse everyday use. These components are designed to be the lightest, with everyday use a secondary concern, which means that durability of groupsets tends to peak around the second highest tier. Running costs should also be factored in, as chains and cassettes are expected to wear out and be replaced several times throughout the lifetime of a bike. Replacing a Super Record chain and cassette will incur a much greater cost than a Chorus equivalent.
Key groupset brands
The big three are Shimano, Campagnolo and SRAM – we’ve got dedicated guides on each of these:
There are a couple of other options:
Rotor road bike groupsets
Spanish manufacturer Rotor has long been making cranksets and power meter, but has recently unveiled it’s first groupset, the Rotor Uno hydraulic groupset. This groupset uses hydraulic fluid to move the derailleurs (and brake calipers) rather than cables or wires. The result is an exceptionally light groupset, although we haven’t yet been able to get our hands on one to put through its paces.
FSA road bike groupsets
Another newer name that is also set to join the groupset market is FSA. Best known for its cranksets and finishing kit, the Italian company has developed the K-Force electronic groupset.
Top Tips when looking at road bike groupsets on built bikes
When buying a bike look at the components it comes with. It is common for bike manufacturers to supply a bike with a whole groupset, minus the brakes and chainset. These are sometimes (but not always) swapped out for cheaper parts to bring the overall price of the bike down. If you are unsure, enquire to establish what you are getting. In some instances it can also be worth investing in a quality frame with a lower end groupset, with a mind to upgrading the components at a later date.