Consisting of the cranks, chainrings (front cogs), chain, cassette (rear cogs), brakes, derailleurs and shifters a groupset is a closed circuit that propels your bike and brings it to a stop again. As you work up the groupset hierarchy, materials change, components decrease in weight and often increase in price as a result. With that in mind, there are a number of things to be aware of when it comes to the engine room of your bike, including the features of electrical and mechanical drivetrains, things to look out for any other differences you may come across on your search for the perfect groupset.
So without further ado, join us as we take an in-depth look at road bike groupsets.
- Related Reading: The Ultimate Road Bike Buyer’s Guide
Pressed for time? Jump directly to each section below.
The Difference Between Mechanical and Electronic Groupsets
Each major groupset provider offers multiple mechanical and electronic options with different names and operating procedures. In the electronic shifting variants, Campagnolo has 'EPS' which stands for 'Electronic Power Shift', Shimano has 'Di2' which stands for 'Digital Integrated Intelligence', and SRAM have 'eTap', which stands for 'electronic tap'. Campagnolo and Shimano both use wires that actuate the front and rear derailleur via the trigger at the shifters. SRAM eTap was the first completely wireless groupset,. which now uses a proprietary protocol called AXS. This works in a similar way to ANT+ or Bluetooth to communicate between the shifters and derailleurs as well as other products in the SRAM AXS product family.
Mechanical shifting works via cables that are attached to the shifters, and run via the frame (internally or externally) to the front and rear derailleurs. Moving the shift lever pulls or releases cables, which then activates the derailleurs to either shift up or down. The benefits of mechanical shifting come in the form of a weight reduction, decreased cost and a more “natural” shift feel. Conversely, the downsides of mechanical shifting is that is as often not as flawless as it relies on the cables to be in perfect working order. Additionally, frames with long frame tubes and acute angles can make installing cables difficult and decrease the performance of the whole system if it’s not regularly adjusted.
Electronic shifting works via wires attached to the shifters and derailleurs that transfer a signal, or via wireless technology similar to Bluetooth or ANT+ devices. The benefits of electronic shifting are the precise shifting, the lack of deviation from the set adjustment, easier shifting at the lever, decreased cable routing difficulty, programmable shifting, and downloadable information on shifting habits and efficiency. The downside of electronic shifting is the system breaking down if batteries are not charged, increased price and generally heavier weight when compared to their mechanical counterparts.
The clear market leader, Shimano has the largest range of road specific groupsets and is a favourite with professional teams too. Shimano pioneered the STI (Shimano Total Integration) lever, which is the most commonly used lever today. The ingenious system allows the user to change gears up or down and brake with one hand. The right-hand lever controls the rear derailleur and front brake (brake orientation can change based on country), while the left-hand lever controls the front derailleur and rear brake. The STI lever allows for multiple shifts and means never having to move your hand position to slow down or change gears. To operate, the brake lever swings inwards to pull the derailleur in one direction, with a smaller shift lever sitting behind the brake lever which releases the cable for the derailleur to go the opposite direction.
Most of Shimano's groupsets are designed to work together (as long as they share the same number of gears), making it possible to mix componentry, although for optimal performance it's best to keep uniformity.
Claris: Claris is Shimano's entry-level groupset best suited to recreational or fitness bikes. It has an 8-speed cassette and comes in either a double or triple crankset providing a multitude of gearing options. The triple is available as a 50 / 39 / 30 tooth crankset, while the double is available in a traditional 50/34 tooth compact set-up or a smaller 46 / 34 option. Claris uses simple and intuitive dual control levers with gear indicators so you'll always know what gear you're in without having to check the cassette at back. Claris also has an option for flat bar road bikes, a purpose-built shift lever known as 'RAPIDFIRE Plus'.
Sora: Sora adds an extra gear over Claris, as such is typically the typically used on entry-level road bikes. With a number of 9-speed cassette’s on offer, a maximum cog size of 30T outback and refinements made to shift quality and durability, Sora represents great value. Sora has a different aesthetic to Claris, more in line with other performance orientated options in the Shimano product lineup. Both four and five-arm cranksets are also offered in double and triple configurations. Additionally, Sora offers 'RAPIDFIRE Plus' shift levers for use on flat bar road bikes as well as front and rear hubs.
Tiagra: Appearing on many entry-level road bikes, Tiagra scores another cog with the 10-speed groupset represents a sound combination of durability and performance. The crankset is also available in a double and triple, with up to a 34T sprocket available on the rear cassette providing a huge range of gears. In order to accommodate the larger sprocket, Tiagra's rear derailleur comes in a long and short cage option. The options for cranksets increases by one, with a 'mid-compact' 52/36 gear option available, which has proven popular in upper-tier groupsets.
105: Considered Shimano's first step into the performance orientated groupset market and 105 is largely referred to as the “working man's groupset” and is the most popular groupset option in the lineup. Overhauled in 2018, 105 R7000 is aimed at the entry to intermediate level road rider. With that in mind, 105 is equal parts durable and reliable and features much of the same technology found on the more expensive Ultegra and Dura-Ace groups. As an 11-speed groupset, 105 features 11 cogs on the cassette, the same as it’s more expensive siblings, allowing riders to mix and match components between the three groupsets. 105 is also the first groupset in the Shimano hierarchy to feature it’s own in-series flat-mount hydraulic disc callipers to complete a full disc-specific groupset option. The rear derailleur comes in a long and short cage option, whilst the four-arm HollowTech II crankset is available in 53-39, 52-36 and 50-34T configurations.
Ultegra: Aimed squarely at intermediate to high-level road riders, the Ultegra R8000 series features almost identical properties to Dura-Ace, benefiting immensely from trickle down tech, albeit with a slight weight penalty. The latest iteration of Ultegra features both rim and disc brake options, including an all-new chain stabilising rear derailleur for road, gravel and cyclocross bikes dubbed Ultegra RX800/RX805. Crankset combinations include 53/39, 50/34, 52/36 and 46/36T, whilst in-series rim and disc brake callipers/rotors, pedals, wheels, hubs and time trial specific shifters complete the line-up.
Ultegra Di2: Ultegra also represents the entry level to Shimano Di2 technology. Unlike the mechanical version which requires cables to change gears, Di2 uses motor-driven mechanics at the front and rear derailleur to provide a crisp perfect shift, every time. The R8020/R8070 Di2 groupsets are slightly heavier than their mechanical counterparts, however, feature a few more features over the analogue groupsets. Shifting can be activated via both Di2 specific shifters as well as satellite buttons whilst Shimano’s own companion app allows riders to customise shift settings, battery use and groupset characteristics for a more personalised riding experience.
Dura-Ace: Dura-Ace is the gold standard of groupsets from the Japanese company. The groupset uses a mixture of carbon fibre, titanium and high-grade alloys to create precise shifting and unmatched reliability. Dura-Ace shift levers have a shorter lever stroke and more ergonomic design to improve rider feel and comfort. A longer derailleur cage is used to accommodate a 30T sprocket with the derailleur cage itself borrowing technology from the MTB world, sitting lower and more central to improve aerodynamics and reduce damage in the event of a fall. Both rim and flat-mount hydraulic disc brake options are offered, as are a line of Dura-Ace level clincher and tubular wheelsets, hubs, carbon fibre pedals, chains, brake pads and bottom brackets.
Dura-Ace Di2: Dura-Ace Di2 gets a significant upgrade from the previous iterations of the Japanese company’s electric groupsets. 'Syncro' shifting is featured as standard, as are lightened materials, higher capacity battery systems and is available to suit both rim and disc-brake configurations.
Campagnolo is the longest standing groupset manufacturer and has been actively innovating within the cycling industry for over 80 years. Many riders have a romantic notion of the Italian company thanks to its longevity, aesthetic and reputation for high-end products. The vast majority of work on Campagnolo components still takes place at the company’s headquarters in Vicenza, Italy.
Campagnolo has five groupsets but enters the road market at a higher price point than both rivals SRAM and Shimano. As such, it's rare to see a Campagnolo groupset on a budget road bike, but very common on high-end Italian road bikes and expensive bespoke creations.
Campagnolo levers feature curved hoods to improve ergonomics and unique shifting, a single lever behind the brake lever is used to go to an easier gear, while a small thumb lever on the inside of the hood is used to go into a harder gear. This design makes it virtually impossible to mistake an upshift for a downshift and vice versa. It's also said to allow easier access to shifting while in the handlebar drops and covering the brakes.
Centaur: With plenty of enhancements and modern touches. The groupset is now 11-speed, has a wide gear range capacity, an updated crankset, two different finishes and even wheelsets to match. The groupset is a lower cost version of the mid-range Potenza with the stylish looks of more fancied Campagnolo groupsets Chorus, Record and Super Record. As the Centaur is targetted at recreational and entry-level cyclists, its chainrings options include the traditional compact 50/34 and the popular semi or mid-compact 52/36, paired with a choice of 11-29T, 11-32T, and 12-32T cassettes.
Potenza: Potenza is an Italian noun for power, intensity and strength and sits as Campagnolo’s mid-range groupset. Potenza features a four-arm crank and re-designed front and rear derailleur to improve shifting. While the Potenza features resemble Chorus, Record and Super Record, a mix of alloys are used throughout the groupset to cut down costs. The introduction of an 11-32 cassette is a welcome addition and requires a change in rear derailleur geometry to accommodate the larger range. The new design allows owners to fit compact (50/34T), semi-compact (52/36T), and standard (53/39T) chainrings to the same crankset.
Chorus: Campagnolo describe Chorus as 'the perfect solution for sophisticated cyclists searching for Super Record performance at a more competitive price. With high-grade carbon fibre featuring throughout the groupset, buyer be warned though that Chrous will still likely be priced in excess of it’s Shimano Ultegra and SRAM Force competition. Chrous has the regular chainring options; 53/39, 52/36, 50/34, but still only the three crank lengths; 170, 172.5, 175 mm.
Chorus EPS: Chorus is the first groupset in Campagnolo's range to have the option of electronic shifting known as 'EPS' (Electronic Power Shift). EPS allows the rider to make adjustments on the fly, the "mode" buttons allowing riders to check battery charge, make fine adjustments to the rear or front derailleur and set the zero position of the rear and front derailleur.
Record: Updated for 2019 Record is a professional quality groupset despite having one groupset sitting above it and as such often compared Shimano Dura-Ace and SRAM Red. With 12-speed shifting and both rim and disc brake options on offer, Record combines carbon fibre and high-quality alloys to create a groupset that is lightweight, looks stunning and is said to perform impeccably out in the real world. With the addition of another cog out back, the shifters, derailleurs, chain, crankset and cassette have all seen a significant upgrade from their outgoing 11-speed counterparts.
Record EPS: The electronic version of the already elite Record groupset. At this level, it is possible to 'manage your bike fleet and personalise the way your Record EPS groupset works inline with your preferences ' via the 'MyCampy App'. You can even add the information gathered from your shifting habits to your usual riding metrics like power, speed, heart rate and distance.
Super Record: As previously mentioned, Campagnolo have been innovating for over 80 years, trying to push the limits of performance and with their elite performance groupset, they think they've found it. The Record groupset was already so good Campagnolo could only come up with one name for a groupset even better, 'Super Record'. Campagnolo describes this as 'the maximum evolutionary and technological expression of a mechanical drivetrain for bikes'. The differences between Record and Super Record are minor, mostly based around the inclusion of carbon fibre, titanium and ceramic bearings, which further decrease weight and improve efficiency. Super Record is for elite cyclists or ones without budget restraints.
Super Record EPS: If Super Record is for 'elite cyclists or ones without budget restraints', Super Record EPS is even more so. The absolute top of the tree when it comes to groupsets, Super Record spares no expense or design innovation to create what Campagnolo calls “the ultimate groupset.”
As well as being lightweight, SRAM is well known for its 'YAW' angle technology. In this, SRAM's front derailleur cage has the ability to rotate as the gears change to maintain a consistent angular relationship with the chain. This optimises chain alignment and is said to improve shifting performance while reducing chain rub.
Shifting with SRAM is controlled by 'Double Tap' technology, utilising only one lever to change up and down, which is separate from the brake lever. Double Tap features throughout SRAM's road range and incorporates 'ZeroLoss' resulting in 'instant and precise' gear changes. It's a bit odd to explain, but a single shift of the lever actuates the derailleur in one direction, continue to push the lever and the derailleur is actuated in an opposite direction.
Apex: Sitting as the entry-level groupset of the SRAM road product line up, Apex features a 10-speed rear cassette, two chainrings up front and a five-arm alloy crankset. The front chainrings are a traditional compact set-up featuring a 50 tooth large chainring and a 34-tooth small chainring, perfectly suited for touring or recreational riding. Apex comes with an 11-32 cassette, perfect for beginners who are after easy pedalling gear ratios. The large cassette range offers more coverage than a standard triple crankset, eliminating the need for a triple crankset at all according to SRAM (who were first to bring the idea to road bikes). To accommodate the wider gear range the rear derailleur has a longer cage and slight variation in geometry.
Apex x1: As the name suggests, Apex x1 features only one front chainring, creating a single derailleur drivetrain. The technology is simple, easy to use and removes potential mechanical issues by having less moving parts. The 1x is available for drop or flat bar road bikes and features an enormous 11-42T cassette. There are four options for the chainrings; 38, 40, 42 and 44T, all of which feature 'X-SYNC' tooth profiles that are 'tall and square' to 'engage the chain earlier than the traditional triangle shaped teeth'. Crank arms are only available in 170, 172.5, and 175mm. The 1x setup is ideal for commuters or those into adventure and/or off-road riding like cyclocross.
Rival: Rival is SRAM's answer to Shimano's 105 groupset aimed at the entry level rider with a lot of technology trickling down from the Force and Red groupsets. A step up to Rival gives you an extra gear on the rear cassette (11), providing 22 gears in total and a huge range with up to an 11-36T cassette available. Rival weighs less than Apex, has hydraulic disc options and a greater range of crankset lengths; 165, 167.5, 170, 172.5 and 175 mm. The chainrings are available in 52/36, 50/34, or 46/36, the traditional 53/39 set up saved for Force and Red. Rival still features aluminium crank arms and machined alloy ring and spiders.
Rival x1: Rival x1 is similar to Apex but extends its chainring options (38, 40, 42, 44, 46, 48, 50T), sheds a little weight, and has an even larger rear cassette available (10-42T).
Force: Force is similar to Rival in a lot of ways but at this price point, carbon replaces aluminium, making an appearance in the rear derailleur and crank arms. The crank arm utilizes unidirectional carbon, which is matched to a forged alloy spider, creating a lighter and stiffer crankset available in 165, 170, 172.5, 175 and 177.5mm. A traditional 53/39 set up is available along with 52/36, 50/34 and 46/36 options. Force is for intermediate to elite level racers looking for a lightweight, high performing groupset. Force too is hydraulic disc compatible and available in a 1x version. The rear cassette option extends to an 11-32 option but requires a longer cage version of the rear derailleur.
Force x1: Force x1 had been predominantly used for Cyclocross at an elite level as Red is currently only available in a double crankset option. The performance and reliability of 1x make it perfectly suited to the demands of cyclocross, but it has started to be seen more on crit specific and triathlon bikes that don't require an extensive gear range. The chainring choice is impressive; 38, 40, 42, 44, 46, 48, 50, 52 and 54 enabling you to customise your drivetrain to any style of riding.
Red: Red is at the top of SRAM's tree in terms of performance, featuring on professional teams and international level triathletes. SRAM describe Red as the 'pinnacle of road racing technology' and it's the lightest groupset on the market. Carbon fibre features more heavily on Red, and the introduction of ceramic bearings further improves performance. The shifters feature 'ErgoFit' technology, which SRAM say 'improves grip and finger wrap with reduced diameter, providing better control and a better transition to the bar'. The crankset features a 'completely hollow construction all the way to the spider' to further improve stiffness and save weight over Force. The mechanical Red 22 can cater for a large cassette sprocket up to 32T.
Red eTap AXS: SRAM eTap AXS is a wireless 12-speed groupset using a proprietary protocol called 'AXS' to communicate between the shifters and derailleurs, via tiny removable and interchangeable batteries located on each derailleur. Similar to its mountain bike stablemates, eTAP AXS requires riders to adopt an all-new XDR freehub to an existing wheelset to fit its 12-speed cassettes. Other changes from mechanical Red include wide range cassettes, direct-mount chainrings, an all-new flat top chain, an updated DUB bottom bracket standard, a fluid clutch rear derailleur and improved shift speed over the outgoing SRAM Red eTap 22. Despite the tiny size of the batteries fitted to the groupset, they have a 1,000km range and can be recharged in 45 minutes according to SRAM, and are compatible for use with both eTap AXS and SRAM Eagle eTap AXS.
Whilst the three manufacturers above definitely dominate the market in terms of popularity, there are a number of other manufacturers in the industry who are looking to shake up the market. See below for a brief detail of some other options to consider.
- Rotor 1x13: First teased at EuroBike, Rotor 1x13 was finally released to the market in early 2019. True to its name, the 1x13 groupset features a single chainring up front and 13-speed out back to make a groupset that said to have a similar range to a traditional 53/39 crankset paired to an 11-28T cassette. Whilst 13 cogs on the cassette is a definite highlight of the groupset, one other unique feature is that the groupset is solely run via hydraulics. As such the 1x13 groupset is flat-mount disc brake specific whilst the front and rear derailleurs are also actuated by hydraulic lines. This is said to make the system largely maintenance free, if not a bit finicky to set-up initially.
- FSA K-Force WE: Italian outfit FSA are known throughout the cycling industry for its high-quality OEM and aftermarket bicycle components, so much so that they’ve taken to developing their own wireless groupset for the road. Standing for Wireless Electronic, K-Force WE much like SRAM eTap AXS is completely wireless, with both front and rear derailleurs and shifters all communicating with each other over an ANT+/BlueTooth Smart protocol. Unlike its competitors, FSA has opted to stick with a 2x11-speed setup. The groupset is finished off with the Italian company’s own brakes, chain, crankset, cassette, and bottom bracket.
Road Bike Groupset Hierarchy
Below is a table that highlights what type of riding each groupset is best suited to, where each sits in the overall hierarchy, and how they compare to each other.
Gear ratios on road bikes vary depending on the purpose of the bike. The gear ratio is a combination of the number of chainrings on the front of the bike, the number of teeth on those chainrings, the number of cogs on the rear cassette and the number of teeth on those cogs.
Traditionally there will either be two or three chainrings on the front, although in recent times some road bikes, particularly gravel bikes, have followed the mountain bike trend of having a single chainring. Having a single chainring minimises potential mechanic issues and simplifies the shifting to the rear cassette, especially given the increasing popularity of 12-speed groupsets for the road. However, despite this, the majority of road bikes will have either two or three front chainrings, although three front chainrings (known as a 'triple') are commonly reserved for recreational, entry-level or touring bikes.
Bikes with two front chainrings are normally split into a 'regular', 'compact' or 'pro-compact' (also called a 'mid-compact' or 'semi-compact' set up). A regular set-up sees the large chainring with 53-teeth and the small chainring with 39-teeth and is most commonly used by professional riders. A compact set-up sees the large chainring with 50-teeth and the small chainring with 34-teeth, which provides easier pedalling ratios when compared to a regular set-up. A relatively new option, the mid-compact set-up, is in between the two - the large chainring has 52-teeth and the small chainring has 36-teeth. A common crankset option for commuting, fitness or cyclocross bike has a 46 tooth large chainring, paired with a 36 tooth small chain ring.
A 'triple' will normally have a 50-tooth large chainring, a 39-tooth medium chainring and a 30 tooth small chain ring.
The front chainring set-up is the foundation for the gear ratios, which the cassette on the back compliments. The cassette is made up of a number of cogs or sprockets which can be changed to make the gear ratio easier or harder. Modern-day cassettes feature 11, or 12 sprockets providing up to 24 gears when paired with two front chainrings but older and more entry-level groupsets have either 8, 9 or 10-speed cassettes. Groupsets with a different number of cassette sprockets require the same speed components throughout the drivetrain to work effectively, you can't simply swap an 8-speed chain with an 11-speed chain and expect it to work. Equally, even groupsets with the same amount of gears (105 and Ultegra for example) will not perform as well when the components are mixed, than if they are all the same.
The sprockets and chain of 12-speed groupsets are thinner to accommodate the extra gears and provide smoother shifting. The required tolerance of 12-speed groupsets is much tighter than 8, 9, 10, or 11-speed groupsets, meaning much careful tuning and fine adjustment.
The most common ratio on an 11-speed cassette is an 11-25 or 11-28, whereby the smallest cog has 11-teeth and the largest cog has either 25 or 28-teeth. The cogs in between these two have a spread of teeth aimed to make shifting between gears a smooth progression. The larger the difference between the smallest and largest cog on the cassette, the greater the chain has to move and the less consistent a rider's cadence becomes between gear changes.
Choosing a bike with smaller chainrings on the front and a larger ratio cassette on the back will provide a greater spread of gears and easier pedalling ratios. A bike with larger front chain rings and a smaller ratio cassette on the back will be more targeted for speed, provide less range of gears and provide consistently smaller changes to a rider's cadence than a cassette with a larger ratio.
Crank length tends to vary according to the size of the bike and rider height. Typically, groupsets will range between 165 mm and 180 mm but aftermarket creations can be made to any length. Most bikes will come with cranks between 170 mm and 175 mm. There is much debate about what constitutes the 'correct' crank length but comfort and efficiency should be the two main priorities when deciding. If you are getting issues with your knees, hips or lower back, look at your crank length in addition to the usual factors like seat height, frame size and flexibility. Adjusting crank length will also require an adjustment to your seat height and potentially other areas such as handlebar height and reach.
Longer cranks: Longer cranks create more torque due to the increased leverage, but require greater force to turn over. The longer the crank the harder it is to maintain pedal efficiency, as it is harder to maintain consistent leverage throughout the pedal stroke when compared to a shorter crank. The longer crank will also require a greater range of motion, producing a straighter leg at the bottom of a pedal stroke and a more acute angle at the top. Ground clearance is also reduced, which could be problematic on tight corners or if you plan to go off-road. Another potential turning issue is the reduced clearance between your toe/shoe and the front wheel.
Shorter cranks: Shorter cranks require less effort to turn over, but have less leverage and produce less torque as a result. A sign your cranks are too short is if you have trouble producing power on flat roads but not riding up hills. Track riders will typically opt for shorter cranks to keep their cadence high and reduce the initial force required to turn over a gear (as they are on a fixed gear and can't change up or down as their pace increases or decreases). Shorter cranks require less flexibility as the range of motion is reduced, but this reduced range of motion can also be an opportunity to move the rider into a more aggressive position without compromising hip angle or reducing power.
Type and quality of brakes will differ from groupset to groupset. There are now four brake types available, none of which are necessarily dependent on the price. The four options are cable operated rim, cable operated disc, hydraulic rim and hydraulic disc brakes.
Cable operated rim brakes feature on the most basic of bikes, right up to the most expensive. Professional riders predominantly use cable-operated rim brakes but some riders and teams have started using disc brakes with many predicting the move to disc brakes permanently is inevitable. Cable operated disc brakes will typically feature on entry level bikes, while hydraulic disc brakes will typically feature on more expensive bikes. Road bikes are built to handle either rim brakes or disc brakes, and it’s often not possible to swap brake types on the same frame.
As with most other elements of the groupsets, as the price increases so do the quality of materials used, which provides lower weight, better modulation (brake control), durability and reliability.