Shimano’s mountain bike groupsets go all the way from the kind of kit you’d find on entry-level off-road and hybrid bikes up to specialist set-ups for extreme downhill racing. Here we look at each series and explain what they can do.
Acera (catalogue number M390)
Shimano does produce cheaper, non-series general-purpose components but Acera is its entry-level complete groupset. That said, flat-bar bikes such as mountain bikes and hybrids tend to feature mixed specifications with a recipe of parts from different groupset series — and sometimes even different brands — so the focus on complete groupsets isn’t quite as strong as in the road bike market. Acera is essentially a nine-speed system, which although basic compared to higher options, is actually aesthetically and practically rather impressive. It comes in double- and triple-chainset models, both of which are heavy and basic but look neat and comes in versions suitable for either an Octalink or square taper bottom bracket. Meanwhile the derailleurs have a relatively futuristic design and work pretty well too — gear changes aren’t super smooth but they are direct. New 9-speed 11-36T Hyperglide cassettes increase range of the rear gears over previous options, while the side-wing front derailleur assists with tyre clearance – something that’s been an issue in the past because of the increasing popularity of 29sers. There’s a choice of standalone RapidFire Plus gear levers and brake levers or integrated Dual Control units. And those brakes can either be no-nonsense V-brakes or hydraulic disc brakes, which have usurped cable-operated (ie, non-hydraulic) discs on the Acera model.
On entry-level mountain bikes you’ll often find Alivio components mixed in with Acera because, although a small step up in performance, they share a nine-speed set-up with both Acera and Alivio derailleurs being able to handle sprockets up to 36 teeth. So what does Alivio offer beyond Acera? Less weight and a few more refinements, such as choice of either top swing or down swing front derailleur; a rear derailleur with better shifting; and slightly more impressive RapidFire levers. Like Acera, there’s also now the option of hydraulic brakes, as well as mechanical disc brakes and more traditional V-brakes.
Deore marks the point where things start to get interesting and much more mountain bike-specific. Not only does Deore come with 10 speeds and excellent hydraulic disc brakes but there’s also a huge choice of front derailleurs to suit any of the very classy double or triple chainsets. The Deore rear derailleurs are also fine bits of kit with some benefiting from Shimano’s Shadow Plus technology, which helps prevent chain drop and chain slap. There is also the option to use Shimano’s I-Spec system, which integrates both brake and gear levers onto one mounting bolt. All in all, Shimano Deore is a fine groupset for dedicated and serious off-roaders, although expect to see it upgraded to 11-speed in 2017.
Unlike the higher-end Shimano SLX and XT groupsets, Deore M6000 hasn’t adopted 11 gears at the back and remains 10-speed. However, it now offers the same effective gear range as SLX, XT and XTR with a 10-speed 11-42T Dyna-Sys cassette the biggest recent change to the M6000 groupset. The new Deore 6000 also gets a four-arm Hollowtech II crankset with double options in 38-28T, 36-26T and 34-24T combinations. The triple option comes sees the choice of 48-36-26T or 40-30-22T. The 2x crankset receives a cosmetic update while new Shadow RD+ rear derailleurs look after shifting duties. Powerful hydraulic brakes take care of stopping duties.
Shimano SLX went through a significant update in 2016 and features a host of trickle-down technology from higher-end groupsets. It’s now an 11-speed set-up and can be run with either a normal double-ring, old-school triple, or even more contemporary 1x set-up. The 11-speed cassettes mean a huge gear range is available — 11-42t — with the rear derailleur being upgraded to a Shadow RD Plus design, featuring a 20 per cent lighter shift action. In fact, the rise of 1x set-ups has recently seen the arrival of an 11-speed cassette, 11-46T option. The hydraulic disc brakes have also been upgraded and seen a reduction in weight. In terms of performance and aesthetics, SLX is a noticeable step up, with gear shifting and chain management particularly impressive.
Deore XT (M8000)
Shimano Deore XT isn’t just a complete groupset, it’s much more than that, with a matching range of wheels and pedals also part of the series. But the beauty of XT isn’t simply the variety it offers, it’s the quality, too. Relaunched last year as an 11-speed set-up, new Deore XT borrows a lot of technology from its big brother, the top-of-the-range Deore XTR. Superb light-action Shadow Plus rear derailleurs are married with a huge selection of front derailleurs and two or three-ring chainsets. Single ring set-ups are served, too, with an incredibly wide 11-46-tooth cassette available. And just to make things easier, Deore XT’s new gear shifters use Optislick cabling to make gear changes even easier. Finally, Deore XT’s hydraulic disc brakes have received an upgrade thanks to the new XT BR-M8020 brakes – a four-piston model compared to the previous two-piston option that provides 20% more stopping power.
Deore XT Di2 (M8050)
Deore XT Di2 takes all the great qualities of standard Deore XT and adds the bonus of electronic gear shifts. Launched in 2016, Shimano Deore XT Di2 includes Bluetooth wireless set-up but the real headline grabber is Shimano’s Synchronised Shift technology, which can use one shifter to operate both derailleurs. This can provide you the next gearing option in sequence and helps to maintain a happy chainline — so rather than being on both big or small rings back and front, the shifting tech will find a happier option. Other changes with Deore XT Di2 include FireBolt shifters, a digital display option and of course those electronic derailleurs. The XT Di2 comes in double- and single-chainring options with the single-ring cassette stretching from 11-40T to 11-46T.
Deore XTR (M9000)
The top of the range mountain bike groupset from Shimano, Deore XTR takes full advantage of all the firm’s off-road component innovations. As well as being incredibly light, Deore XTR comes as an 11-speed option and offers superb performance as well as incredible looks. But then again, so does Deore XT, why pay more? Well Deore XTR can be specified further than any other Shimano groupset with a choice of either race or trail-specific brake levers, hydraulic disc brake calipers and even chainsets. So the weight-conscious can opt for ‘race’ and get the most svelte kit possible, or bigger-hitters can opt for ‘trail’ and benefit from those components’ unique abilities. As with Deore XT there is a choice of front derailleurs and chainsets, and the rear derailleurs maximise Shimano’s Shadow Plus chain management technology.
Deore XTR Di2 (M9050)
All the quality and competence of standard Deore XTR but with the added fun and flair of electronic gear shifting for an absolutely precise, self-feathering drivetrain. Deore XTR Di2 requires a single programmable FireBolt shifter which can operate both front and rear derailleurs by itself; a Di2 display unit; the 11-speed Di2 Shadow Plus rear derailleur; and a choice of either double or triple chainset compatible front Di2 derailleurs. It also comes in single-ring option for cross-country racing or endure/trail. Then plug in the battery and enjoy.
Zee and Saint
Deore XTR and its Di2 equivalent might be Shimano’s best traditional groupsets, but the company also boasts downhill-specific single chainring series, too: Zee and Saint. Both come with 10-speeds and hydraulic disc brakes, and while both are impressive set-ups, Zee is aimed more at amateur downhillers, while Saint is good enough for pro racers.