A groupset is a collection of bike components designed to work together. These days it usually means the gears and brakes on your bike. The term once included the hubs and headset too, but threadless headsets knocked the traditional groupset makers — Shimano and Campagnolo — out of the market. Nevertheless, the groupset is where a lot of the money in a new bike goes.
Japanese company Shimano is the most popular groupset manufacturer with a range of groupsets at different prices. It’s constantly updating the groupsets too, with the newest features debuting first on its top-end groupset, Dura-Ace, before eventually filtering down through the range.
Whether you’re buying a new bike, or looking to build one from scratch, it’s good to know what your options are. The more expensive groupsets are lighter and usually offer smoother gear shifting and superior braking performance, and you get more gears and with the more expensive groupsets, 11-speed on Dura-Ace, Ultegra and 105, down to 8-speed on entry-level Claris.
Here’s an overview of the entire road lineup, with the most expensive at the top of the list:
The range includes six mechanical groupsets, using cables to operate the front and rear derailleurs, and there are two electronic groupsets. First introduced in 2011, electronic groupsets have proved to be extremely popular, with precise gear changes, long battery life and good durability. Whether you choose mechanical or electronic comes down to budget and personal preference.
Complete sets of the last versions of Dura-Ace, Ultegra and 105 components have sold out from major retailers. You'll still find individual parts, though, so we've retained some basic information about them here.
And then there's GRX, Shimano's gravel-bike component series that sits off to one side of the main road bike component range. We'll cover GRX here as well, as these are components for drop-bar bikes, but the way Shimano has organised GRX doesn't quite conform to their usual way of doing things.
GRX isn't a single groupset, it's a collection (a 'series' in Shimano-speak) of components at different quality levels that share similar colouring and styling so that bike manufacturers can mix them to tailor their gravel bikes.
There are three quality levels in GRX: RX810, RX600 and RX400. These correspond to Shimano's Ultegra, 105 and Tiagra levels respectively. RX810 and RX600 are 11-speed; RX400 is 10-speed. As with Tiagra, RX400 has the same ratio of cable pull to sideways movement as the more expensive, 11-speed systems, so you can, in theory, mix them all.
Where GRX departs most from Shimano's road components is in the design of the STI shift/brake lever units. All have new details designed to make it easier to keep your hands firmly on the hoods as you rattle over rough surfaces.
The GRX chainsets are available with double or single chainrings, which is a first for a drop-bar offering from Shimano. There's no RX400 chainset though. Instead there's a variant of the RX600 chainset with 10-speed spacing. Shimano has moved the chain line out 2.5mm compared to road groupsets so there's room for bike manufacturers to move the chainstays apart and provide clearance for fat tyres. That means you'll need a GRX front derailleur with a GRX chainset.
Similarly there are no RX600 derailleurs; you use the RX810 derailleurs with the RX600 shifters, brakes and chainset if you want a mid-priced 11-speed bike. Both the RX810 and RX400 rear derailleurs are available in versions for single and double chainrings. The single-ring derailleurs will shift up to 42-tooth sprocket, while the double-ring derailleurs go up 34 teeth or 36 teeth in the case of RX400. All the GRX derailleurs have clutch mechanisms to reduce chain slap when riding off-road.
All GRX brake calipers are flat mount. If you have an old post-mount frame that you want to upgrade with GRX you'll need BR-RS785 post mount calipers, and to be aware of one little gotcha that Mike Stead details in his GRX review.
There are no specific GRX cassettes, chains, bottom brackets or brake rotors; you just use the ones from the equivalent road or mountain bike groupsets.
Like Ultegra, RX810 is also available in a Di2 electronic-shifting variant.
Let's take a closer look at the options and details at each level.
The flagship GRX level is equivalent to Ultegra road components in quality, but has a host of details and options offered nowhere else in Shimano's range. These include:
In addition, GRX RX810 offers 42- and 40-tooth single chainsets. Both double and single-ring chainsets are available in 170mm, 172.5mm and 175mm lengths.
The electronic-shifting version of GRX boasts the same feature set as RX810, but with click-whirr shifting.
The cheaper of the two 11-speed GRX sets has a 46/30 double chainset or 40-tooth single ring chainset. Both double and single-ring chainsets are available in 165mm, 170mm, 172.5mm and 175mm lengths.
The RX600 brake/shift levers lack the Servo Wave feature of the RX810 STI units, but have the same tweaked pivot point, grippy cover and anti-slip brake lever.
If you want the widest possible gear range from your GRX set-up, then you want the 10-speed RX400 derailleurs because the rear unit will shift up to a 36-tooth largest sprocket, the greatest capability of any Shimano drop-bar rear deraiilleur.
Shimano's flagship component group gets a major facelift and some new options for 2017. The mechanical and Di2 electronic groups share the same chainset, brakes and other non-shifting components, but with Di2 you get switches on the brake levers, derailleurs with built-in motors and the battery, wiring and control box that ties it all together.
The major new feature of Di2 is Synchronized Shift, a technology borrowed from Shimano's mountain bike Di2 components. Rather than buttons controlling front and rear derailleurs independently, one pair of buttons moves up and down the gear ratios, making shifts at the front or rear derailleur, or both, as necessary.
Shimano says this is “designed to simplify gear choice and reduce decision making in racing situations.”
There are two modes. If you go for the Full Shimano Sychronized Shift, the front derailleur reacts based on the rear derailleur’s shift action. You don’t need to use two separate shifters, you just use one. Press one button and the gear will get harder to turn, press the other button and the gear will get easier. If that requires a front shift, the system will take care of that automatically; you don’t need to worry about it.
If you go for Semi Shimano Synchronized Shift mode: the rear derailleur reacts based on the front derailleur’s shift action, shifting to the next most appropriate rear gear when the rider makes a front shift.
A new junction box is not only very tidy — it can be hidden inside the end of the handlebar — it provides wireless ANT Private connectivity to third-party devices. The system also offers a Bluetooth connection to phones and tablets running Shimano's E-Tube software so you can program the shifting behaviour.
Buy Shimano Dura-Ace Di2 if you want the state of the Shimano art.
If your budget won't stretch to the electronic version of Dura-Ace, the mechanical version is by no means second best — it's still a superb ensemble. The 9100 group offers perhaps the widest range of options Shimano has ever offered in road bike components, including a power meter, hydraulic disc brakes, a wider gear range and an increased selection of wheels.
The 9100 group features new derailleurs too, using design features that originally appeared on Shimano's mountain bike parts to reduce the chance that the rear mech will get damaged in a crash. Just one rear derailleur will handle any gear system you choose, including the new 11-30 cassette.
Shimano's rival SRAM has offered power meters since it acquired Quarq in 2011. With the 9100 group Shimano adds a very tidy power meter to its collection. How tidy? You can see in the pic to the right that the electronics are barely visible:
The inclusion of hydraulic disc brakes in the Dura-Ace line shows how completely Shimano has embraced road bike discs. Previously Dura-Ace equipped bikes with discs had to use Shimano's non-series brakes and levers; now they match.
If you're using rim brakes, the 9100 Dura-Ace calipers have been subtly redesigned so they'll accommodate 28mm tyres.
Finally, there's a big range of wheels in the latest Dura-Ace line up. The new C40 and C60 wheels have 28mm wide carbon fibre rims that are 40mm and 60mm deep, respectively.
Buy Shimano Dura-Ace if you're racing or doing mega distances and you want the best mechanical shifting.
As mentioned above, the previous version of Shimano's electronic groupset has just about vanished from retailers, but individual components are still available.
Dura-Ace Di2 uses a similar shifting design to mechanical, but instead of pushing two levers, you push two buttons positioned next to each other. If you want to move two or more sprockets at a time, rather than swinging the lever further like you do with a mechanical system, you just keep the button pressed down.
If you want, you can customise the shift function. Plug the groupset into a computer and you can configure the shift buttons in any way you want. You can personalise the speed of the shifting, the number of sprockets that will be shifted, and even control the rear derailleur with the left hand. An advantage of Di2 is the option of adding additional shifter pods, satellite shifters that can be fitted to the tops or the drops.
This Di2 groupset was the first from Shimano to feature an internal battery, which you can hide inside the seat post. Worried about it going flat? It’s good for a claimed 2,000km between charges. That’s lots of riding. Apart from charging the battery, there is very little to go wrong with Di2, and it’s actually really well suited to winter riding and long distance rides through demanding conditions.
Dura-Ace was the first Shimano groupset to go to 11 sprockets, causing some controversy at the time, but widely accepted now. Shimano has evolved the ergonomics of the hoods (the rubber part at the top of the brake lever) over the years and this design has trickled down through the ranks. This version was replaced by the current Dura-Ace 9100 and complete groupsets have all but vanished from retail.
Buy Shimano Dura-Ace 9000 if you want a pro-level groupset at a bargain price
Shimano announced the latest version of its number two groupset in June 2017; both mechanical and electronic versions are now widely available and appearing on bikes.
If you want high performance without the hefty price tag of Dura-Ace, then Ultegra is probably the pick of the range. Since the 6800 update, the gap between the two has been narrowed, and the R8000 incarnation looks an awful lot like the current version of Dura-Ace too. Ultegra shouldn’t be overlooked too quickly if you want high performance and decent weight components.
It’s a favourite with amateur racers because the weight penalty is minimal, especially if built onto a decent carbon fibre frame, and the performance is nearly identical. You still get the carbon fibre brake lever as well like you do on Dura-Ace, and the cranks, brakes and derailleurs share the same design as Dura-Ace.
Dura-Ace is really aimed at racing bikes, making Ultegra a more versatile groupset. With a range of chainring and cassette options, it can be fitted to all sorts of bikes, from racing cycles to touring and adventure bikes. From an 11-23t cassette and 53/39t chainset for the racers to an 11-34t cassette and 50/34t compact chainset for sportive riders, it covers a lot of uses.
RRP for the full mechanical group is £1,100 and £1,700 for the electronic version.
R8000 component weights are very similar to Ultegra 6800. The significant differences are in the shifting, which gets an Ultegra version of the Shadow rear derailleur from Dura-Ace 9100; the brakes, which have been shaped to make room for 28mm tyres; and the sprockets which now have an 11-34 option. The larger cassettes require the use of the medium-cage rear derailleur, which has been reported as working with even larger sprockets such as the 11-36 and 11-40 cassettes Shimano makes for mountain bikes, though we haven't yet tried this.
Like the previous incarnation, there's just one chainring bolt circle diameter that will take chainrings from 34 to 53 teeth. You can get the chainset with pairings of 53/39, 52/36, 50/34 and 46/36. You could change the chainrings for the riding you're going to do: a 53/39 for a race, say, and a 50/34 if you're holidaying in the Alps.
Ultegra is also available with a Di2 option. It's Shimano’s most affordable Di2 groupset, and there is no 105 Di2 on the horizon at the moment. Like Dura-Ace, both Ultegra groupsets are 11-speed.
Buy Shimano Ultegra if you want performance without the price tag of Dura-Ace.
Ultegra 6800 was functionally very similar to the current R8000, though not quite as versatile. Complete groupsets are now very hard to find, but there are plenty of individual components still around.
This generation of Ultegra saw a new chainset that uses the same spider design as Dura-Ace,and dropped the previous difference between the spider sizes for racing and recreational chainsets. That made changing rings easy, so you could easily swap rings from racing to riding in the mountains without removing the cranks. The rear derailleur came in short- and mid-cage lengths and can work with up to a 32-tooth sprocket on a wide-range cassette. Cassette options range from 11-23 right up to 11-32, with plenty of options in the between the two extremes.
For the 2017 bike model year we got a new Dura-Ace groupset, for 2018 Ultegra got a makeover and for the 2019 model year (which pretty much started in July 2018) Shimano's most popular groupset gets a makeover and a hike in model number from 5800 to R7000.
The main mission of 105 remains the same: excellent performance at a sensible price. It’s a very good looking groupset too and while it's a bit heavier than Dura-Ace and Ultegra, the performance runs both very close, with good shifting and braking. It’s heavier than Ultegra, but you have to be a weight weenie to worry about that.
Many of the changes from 105 5800 are visual, bringing 105 R7000 into line with the styling cues of the other two 11-speed groupsets, but there are some performance improvements too. The shift lever throw has been shortened for faster, crisper transitions, and the rear derailleurs have greater capacity. The SS short-cage derailleur can now handle a 30-tooth largest sprocket, while the long-cage GS model goes up to 34 in theory, and in practice will cope with a whopping 40-tooth sprocket.
The rear derailleurs are Shimano's 'Shadow' design with the main parallelogram moved back and down by an extra pivot that effectively extends the gear hanger so the derailleur is tucked under the chainstay more, reducing the chance of crash damage.
The front derailleur gets the compact toggle design of Dura-Ace and Ultegra so there's no longer a gert long lever arm poking skywards from the front mech.
The big news in braking is that 105 R7000 gets its own hydraulic disc brakes and levers rather than having to make do with brakes that were 105 quality but lacked the logos and styling of the rest of the group. A disc-braked 105-equipped bike will now look 'of a piece' as it were.
Speaking of brakes, there are also restyled rim brakes for old school types. They follow the Ultegra and Dura-Ace convention of the quick-release lever tucking under the brake arm and have a couple more millimetres of brake drop than the previous 5800 brakes so they'll work with bikes that have a bit more room for fatter tyres.
You see a lot of entry-level and mid-range bikes specced with Shimano 105. It’s the workhorse of the Shimano groupset range, and features on bikes covering a really wide price band. Sometimes it gets mixed with other branded parts to meet key price points, but a full 105 groupset is definitely something to look for, as there really is no weak part of the groupset.
Buy Shimano 105 R7000 if you want the latest version of the most affordable 11-speed groupset
Complete groupsets seem to have run out, but there are still plenty of components from the previous version of 105 in the shops and they're excellent value for money, especially if you don't need the relatively small performance tweaks of the R7000 parts. It’s a very good looking groupset, but more than that, it’s an excellent performance groupset for the money. It’s a bit heavier than Dura-Ace and Ultegra, but the performance runs both very close, with good shifting and braking.
Buy Shimano 105 if you want the most affordable 11-speed groupset
Shimano’s fourth-tier groupset was last had a major update for 2016, and Shimano announced some tweaks and extra options in 2019. The changes bring it the appearance of Shimano 105 above it, with the same four-arm crankset and new shifters, with the gear and brake cables hidden underneath the bar tape. As well as the drop-bar kit, Tiagra will be available with flat bar levers and shifters, so expect to see it on commuter and city bikes as well.
The latest tweaks include new hydraulic STI units with a better lever shape and improved shifting, and an option of a 48/34 chainset.
Tiagra retains the 10-speed configuration, though, and that could be a deciding factor if choosing between Tiagra and 105. There’s no 53/39t chainset option for Tiagra either. Shimano reckon that most people buying a Tiagra-equipped bike probably won’t be racing it and won’t need the really high gears. The 52/36t, 50/34t and 50/39/30t triple chainset options still provide plenty of range, and 52/36t is just fine for most racers.
Buy Shimano Tiagra if you want good value and performance, and don’t mind not having 11-speed (but for another £100 (less if you shop around) you can upgrade to 105)
Underneath Tiagra is Shimano’s Sora groupset, which had a major facelift for 2017. It now matches the higher groups in the range visually, with its four-arm chainset, and a similar grey finish (though we can't be the only ones who wish for a shinier option). It’s a 9-speed groupset, but it’s still excellent for the money and does 90% of what the more expensive groupsets do; it just weighs a bit more.
You get proper Dual Control gear shifters, with the brake lever changing down the cassette and the smaller lever changing to a higher gear. That’s essentially the same system as used to be on Dura-Ace a few years ago. You have double and triple chainset options, and the rear derailleur will accommodate an 11-32t cassette along with a 50/34t compact chainset.
Other similarities with the more expensive groupsets include the Hollowtech 2 bottom bracket, with the bearings sitting outboard of the frame.
Buy Shimano Sora if you want performance and value
Claris is Shimano’s most affordable road bike groupset and is what you can expect to see on sub-£500 road bikes. The most recent update to the groupset saw Claris get the four-arm, fixed-axle chainset design of higher groupsets. Claris really does have the quality feel of the more expensive Shimano groupsets.
It’s an 8-speed groupset and is aimed at beginner and new cyclists, and so you have triple (53/39/30) and compact (50/34) chainset options, along with an 11-34 cassette. Getting up climbs won’t be a problem with the lowest gearing available with Claris.
Buy Shimano Claris if you’re on a budget
We can't have a guide to Shimano groupsets and not mention the brakes. Shimano offers a choice of regular dual pivot or newer direct mount brake calipers, and also an increasing choice of disc brakes. Most groupsets now have dedicated disc brakes, and there still plenty of 'non-series' disc brakes around too, with options for electronic and mechanical shifting. The 105 R7000 disc brakes haven't yet reached retailers.
Shimano says these are its first discs designed specifically for road bikes, rather than being adapted from mountain bike brakes. At an RRP of £450 per end for the mechanical-shifting version they're also the most expensive brakes Shimano has ever made. Like the R785 and RS685 brakes, below, they're available with 140mm and 160mm CenterLock rotors.
Disc brakes have numerous advantages over rim brakes: they're less affected by water; they're unaffected by rim damage and they provide finer control over braking power than is possible with rim brakes.
Hydraulic brakes also self-centre and automatically compensate for pad wear, neither of which you get with cables, and both of which are real benefits.
Buy if: You want Shimano's best disc brakes — and you have deep pockets.
With the R8000 components, Shimano has introduced its first Ultegra-labelled disc brakes, with variants at the hydraulic levers for mechanical and electronic shifting.
Like the previous non-series disc brakes they use Shimano's Flat-Mount standard for a tidy appearance.
The first Shimano 105-level disc brakes were pretty good, but with the new hydraulic system, the R7020 lever and the R7070 calliper, Shimano has upped its game significantly. They're still quite expensive as an upgrade, but definitely one to look out for if you're in the market for a new disc-braked road bike.
The new R7020 lever is a full redesign and it's a much better overall shape. The extra width of the lever at the bottom meant that the bottom of the hood sat away from the bar tape a bit; it was noticeable close up but not really an issue.
The 105 brakes work brilliantly out of the box, and they're almost entirely fuss-free. These brakes bite when you'd expect them to in the lever travel, and from there there's masses of stopping power available as and when you need it. The reach is adjustable, but there's also a new, smaller lever (R7025) that should be ideal for those with smaller hands. The amount of effort you have to put in to control your speed on the steep, loose back road descents round here is genuinely a revelation compared to rim brakes or mechanical disc brakes.
The 105 level hydraulic disc brakes are based on the RS685 hydraulic brakes with mechanical shifting (below), but have a new ergonomically shaped hood design. To save weight, and keep the cost down, the brake levers are aluminium rather than carbon fibre. There's 10mm of reach adjustment so you can tune the lever to your hands.
Shimano announced these Tiagra-level disc brakes in March 2016 and they're now a common sight on bikes around the £1,200 mark. The lever shape looks very much like that of the 11-speed RS505 hydraulic lever, although the BR-RS405 lever is 10-speed rather than 11-speed. Tiagra is currently Shimano's only 10-speed road system, so while they're not startlingly cheaper than 105, they're the only game in town of you want to upgrade a 10-speed-equipped bike to hydraulic stoppers.
Shimano’s first road-specific disc brake offers a genuine improvement in braking power and control. The system comprises brake calipers, disc rotors and brake levers, and you can combine with either Dura-Ace Di2 or Ultegra Di2 11-speed groupsets.
Shimano's road disc brake system has been designed for use with 140mm or 160mm rotors, with the idea being that users can choose the size to suit their weight and intended use. The rotors are designed to combat overheating with fins and grooves. They are CenterLock only, there's no 6-bolt option.
Buy if you want electronic shifting and hydraulic disc brakes
But what if you don't want Di2 with your hydraulic disc brakes? Shimano was listening, and RS685 is the result. It offers mechanical gear shifting with hydraulic disc brakes. Shimano sees this as an Ultegra level brakeset but as it’s 11-speed it’s compatible with Dura-Ace and 105.
ST-RS685 uses the same brake caliper as BR-RS785, it’s just the brake lever that is actually different. Shimano has included a mineral oil reservoir and brake system in the mechanical lever while managing to keep that lever compact. The lever features a 10mm reach adjustment to customise the fit for people with smaller or larger hand.
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David has worked on the road.cc tech team since July 2012. Previously he was editor of Bikemagic.com and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds.