Guide to groupsets: learn why your bike has matching components

A groupset is a collection of matching components used by a bike manufacturer to turn a frame into a bike. But confusingly, the term doesn't cover all the parts on a bike, so let's take a look at what it does cover, and why groupsets exist.

The first groupsets were produced by Italian component maker Campagnolo and just as today, a groupset was a collection of components that matched visually and in quality and function. The shapes of the various cast, forged and machined parts of a groupset all follow similar lines. Often there will be a common colour too, with various shades of grey currently in vogue.

Who makes groupsets?

The big names in bike component manufacturing are Shimano, Campagnolo, and SRAM, and these are the brands you'll see almost exclusively on the groupsets fitted to bikes. In fact, you'll have to look fairly hard to find anything but Shimano, such is the Japanese company's domination of the market. You'll find SRAM groupsets on a few mid-priced bikes, but this American-based company is currently focussing on very high-end bikes with its wireless eTap electronic shifting, and on cyclocross and gravel/adventure bikes with its 1X transmissions that combine a single chainring with a very wide-range sprocket set. Taiwanese/Italian manufacturer FSA has been working on groupsets for some years and launched an electronic system in 2018, but it hasn't been widely adopted.

There used to be more. Mavic made some strikingly-styled groupsets in the 1980s, and we previously wrote about the demise of SunTour of Japan and Zeus of Spain. Sachs, part of the German Mannesman industrial conglomerate, made groupsets in the 1990s before selling its designs and production facilities to SRAM. A few other brands have appeared on groupsets, but usually some of the parts have been rebranded components from other manufacturers. Italian company Miche, for example, used to offer groupsets with rebranded SunTour derailleurs, while Galli, also from Italy, made its own brakes and derailleurs but rebranded other companies' parts for the rest of its groupsets.

Today, each of the big three makes a range of groupsets covering bikes from the entry level up to professional racing. The table at the foot of the page lists them, and gives an idea of the cost of the bikes you'll find them on.

What's in a groupset?

Campagnolo invented the groupset. Dripping with carbon fibre and titanium, Super Record EPS is its top offering.

A modern groupset usually comprises brakes, brake/gear levers, chainset, derailleurs, chain and sprockets. That's changed over time, though. For example, there was a time when a groupset included pedals and hubs. Groupset makers still offer hubs and pedals that are designated as part of a group, but it's rare to see them on off-the-peg bikes. Bike makers usually buy complete wheels, sometimes from the groupset manufacturer — Shimano, Campagnolo and SRAM all make wheels — sometimes from another company. Bikes often come with very basic pedals, or none at all. The customer is expected to fit their chosen pedal system. Campagnolo and Shimano used to offer seatposts, Shimano made headsets and handlebar stems, Campagnolo has dabbled in saddles and for a while made highly-regarded rims.

What about the other bits?

A bike's bar, stem, saddle and seatpost will come from a different company than the one supplying the groupset. There's no particular reason for this, except that groupset makers tend to have long-standing specialisation in moving parts and leave the less complicated components alone.

But we're talking about the bike industry so it's Not That Simple. Some manufacturers of non-groupset components have expanded beyond that original remit, notably FSA and Ritchey with headsets, wheels and chainsets. From the other direction, Shimano owns Pro Bike Gear, which makes bars, stems, saddles, seatposts and wheels, plus bags and accessories. You'll need tyres and tubes, but it's otherwise possible to build a completely Shimano/Pro-equipped bike, and you could do the same with FSA if you start with its gear system.

Why have a groupset at all?

Trek's top-end Madone SLR 9 uses SRAM's latest wireless electronic AXS 12-speed groupset

We've already touched on two reasons why groupsets exist: matching aesthetics and matching quality. A bike with a complete groupset looks good, because the chainset, brakes, levers and derailleurs will all be the same colour and share other visual features. Perhaps more importantly, the quality of all the parts will be similar, so you can expect them all to be similarly durable. The metal treatments and high-strength alloys that make pivots and bearings more durable and that also make parts lighter are expensive, so better groupsets are pricier. If you ride 10,000 miles per year, the reliability of an expensive groupset is a decent investment; if you're a 2,000 mile-a-year weekend warrior, perhaps not so much.

Materials themselves may delineate groupsets. You won't find any carbon fibre in Campagnolo's entry-level Centaur groupset, but its top-end Super Record groupset is positively dripping with composites, as well as a fair amount of titanium. That use of high-tech materials makes Super Record the lightest groupset on the market, as well as the most expensive.

Another reason is that a bike with a complete groupset almost always works better than one with a mix of parts from different manufacturers. Component makers design their shifters to pull just the right amount of cable for each gear shift or braking action, and their sprockets and chainrings to grab their chains and move them smoothly from one tooth to another. Change almost any component and things won't work quite as well.

That said, some manufacturers are pretty good at making compatible parts. SRAM sprockets work well enough in Shimano transmissions and it's not unusual to find KMC chains on bikes equipped with any of the big three's groupsets. In fact, KMC is widely reported to supply chains to Shimano, so you'd expect its chains to work with Shimano gears. Nevertheless, with rare exceptions, if you want your bike to work as well as it possibly can, then fitting a complete groupset is the way to go.

How many gears?

Aside from weight and durability the main difference between cheaper and more expensive groupsets is the number of gears you get. The latest top-end groupsets have 12 sprockets on the rear hub (and 13 in the case of Campagnolo's Ekar gravel bike groupset), giving a wide range of closely-spaced gears. From the next tier down to the middle of the range, you find 11-speed transmissions.

When it comes to groupsets you'll find on bikes in the shops, Shimano's Tiagra transmission is the only common 10-speed set-up. SRAM's Apex groupset is also 10-speed, but it's practically vanished from off-the-peg bikes.

If your needs are more modest, Shimano is the only game in town, with the 9-speed Sora groupset and 8-speed Claris.

Stopping options

Just a few years ago there was only one way of slowing down a road bike, with brakes that acted on the wheel rims, operated by cables. Since then,  disc brakes have become common on bikes from about £1,000 and up. From about £1,500 they use hydraulics to get braking force from lever to brake; below that you'll find conventional cables.

All the major manufacturers now offer groupsets with disc brakes; Campagnolo was the last to come to the party, and aside from the grizzling of a few retrogrouches they're now an accepted part of the bike component universe. While they're a bit heavier than rim brakes, they offer better control, are less affected by the wet and still work if your rim gets damaged or you break a spoke.

The rise and rise of electronic shifting

Component manufacturers have long been intrigued by the idea of using motors to operate derailleurs instead of having the rider yank a cable to make a gear shift. The idea is that shifting can be made faster, more precise and more reliable if you take clumsy human beings out of the process.

Mavic had a couple of attempts at electronic shifting with the Zap and Mektronic systems in the 1990s, and SunTour had a chainset-based system called BEAST (for Browning Electronic Accushift Transmission — Browning was the family of inventors behind the design, AccuShift was SunTour's term for indexed gear systems). All suffered reliability problems. The SunTour/Browning system just didn't like getting wet and muddy, a serious problem for a mountain bike component, while Mavic's systems were a victim of their own ingenious design. The power needed to make the shift happen in a Mavic system came from the movement of the chain, which meant that the batteries and solenoids could be small and light, but the mechanism to take the motion of the jockey wheel and turn it sideways was quite delicate. BEAST, Zap and Mektronic were discontinued and the idea faded away for a few years.

In the mid-2000s prototypes of Campagnolo electronic shifting systems began appearing on pro riders' bikes. Even though these were clearly quite advanced development units — you could see mould marks, indicating that Campagnolo had gone to the expense of making moulds for the composite parts — Campagnolo remained tight-lipped about when they'd actually be on sale.

In 2009, Shimano became the first of the major groupset makers to actually offer an electronic-shifting system for road bikes with the Dura-Ace Di2 system, though Shimano registered the 'Di2' trademark in 2000 and offered electronic Nexave rear mechs for hybrid bikes in the early 2000s.

Dura-Ace Di2 was rapidly followed by Ultegra Di2, and Campagnolo finally unveiled Record EPS in 2012. SRAM responded with eTap ditching the wires between shifters and derailleurs which makes installation incredibly easy at the expense of slightly slower shifts compared to Shimano.

More than a decade after Dura-Ace Di2, electronic shifting is clearly here to stay and has proven functional and reliable.

What's the future of groupsets?

Campagnolo's Super Record EPS 12spd groupset, introduced for the 2020 model year, is the state-of-the-art electronic-shifting groupset

The barrier to entering the groupset market is high. Most of the customers are bike manufacturers with well-established relationships with their existing suppliers. You need substantial amounts of heavy machinery for the forging, casting, stamping and moulding processes that convert raw metal to bike parts, and either robots or inexpensive labour to assemble them.

As a result, nobody enters the field with a complete groupset. The trick is to get started with a part that's better than what's already available, or at least very different from it. SRAM did this with its throttle-style gear shifter GripShift, and expanded by buying other companies like Sachs (derailleurs), Avid (brakes) and Truvativ (chainsets).

The rear derailleur of the FSA K-Force WE electronic groupset

FSA hasn't made the inroads we expected when prototypes of an FSA electronic gear system, dubbed K-Force WE appeared on the bike of top Italian rider Ivan Basso at the 2016 Tour de France. A few weeks later FSA showed off the new shifters at the Eurobike show and our Dave Arthur was able to take it for a spin. 

We tested K-Force WE when it finally became available and found it had some way to go to catch up with the electronic groupsets from Shimano, Campagnolo and SRAM. Since then it looks like FSA has squashed some of the bugs. In August 2019, Angel Madrazo Ruiz of the BH-Burgos team won a stage of the Vuelta a Espana using K-Force WE, but it's still incredibly unusual to find K-Force WE on an off-the-peg bike.

The reason it took so long for FSA to get a groupset out is probably that decent-quality road bikes now all have combined gear and brake levers. There are only so many ways to do this and they're all covered by patents held by Shimano, SRAM and Campagnolo. However, Shimano introduced its STI brake/shift levers in 1990, so its patents on that design should now have expired. That we've not seen copies yet is testament to Shimano's technical expertise in getting a quite delicate mechanism to work reliably.

Similarly Rotor started out making cranks and chainrings and their signature product is still the elliptical chainring, claimed to smooth out a rider's power delivery. They also offer an innovative hydraulically-actuated 13-speed gear system, along with hydraulic disc brakes, so can claim to be a groupset manufacturer. Again, though you won't find Rotor compoents on off-the-peg bikes

The trend over the last few years has been to ever-greater integration between parts, and that will continue. In the days before indexed shifting you could use a Campagnolo derailleur with Shimano gear levers (though Campagnolo derailleurs of that era shifted so badly it's a mystery why you'd want to). You can't do that now and be certain the indexing will work properly, nor should you use Shimano levers with Campagnolo brakes — they have different cable pull requirements. And you definitely can't use SRAM hydraulic brakes with Shimano levers because they use different, totally incompatible hydraulic fluids.

As for what the future might bring, imagine a system that senses that you're braking and changes gear for you. That would require a level of integration beyond the current state of the art. Or how about a seatpost that automatically adjusts your saddle height within a range: lower for descending, higher for climbing? Or how about an electronic system that talks to your power meter and keeps you in the necessary gear to put out your target power for a training session? To be honest, we're amazed you can't actually buy that last one yet.

Read more: Your complete guide to SRAM road bike groupsets
Read more: Your complete guide to Campagnolo road bike groupsets
​Read more: Your complete guide to Shimano road bike groupsets

Know your groupsets

The table below lists the groupsets currently offered by Shimano, SRAM and Campagnolo, along with the recommended retail price of a complete set of each one, derived by simply adding up the RRPs of the individual parts. You'll almost always be able to find them for less than RRP, but the prices give you an index of the relative quality of each groupset.

We've also listed the approximate price range of bikes with each group. We have to stress these ranges are very approximate. Some groupsets — especially those from Campagnolo, and non-AXS SRAM groupsets — are very uncommon on off-the-peg bikes. It's also now hard to find high-end bikes equipped with rim brakes.