Shimano Deore has made the jump to 12-speed with the new Deore M6100 mountain bike groupset, adopting nearly all of the tech seen on the brand’s higher-tier options and getting a premium-looking finish that belies its affordable price point.
The shift to 12-speed follows the release of Shimano’s SLX M71000, XT M8100 and XTR M9100 groupsets, which are all also 12-speed.
Much of the tech seen on these higher-tier groupsets – including the adoption of the new-ish Micro Spline freehub body – is now seen at a Deore level.
It's fair to say Shimano's higher-tier groupsets get increasingly nicer finishes, lighter materials, more adjustment and some other interesting features.
However, looking at the key tech features that will actually make a difference to your day-to-day riding, there is now very little that separates even Shimano’s top-tier groupsets from Deore, and that can only be a good thing for riders.
Alongside the new headline 12-speed groupset, Shimano is also releasing refreshed 11-speed (Deore M5100) and 10-speed (Deore M4100) groupsets.
These groupsets are primarily aimed at the OEM market (in other words, groupsets you'll see specced on complete bikes) and do not use a Micro Spline freehub body for their cassettes.
The new line-up will undoubtedly present interesting upgrade options for riders on older 10- and 11-speed Shimano mountain bike groupsets.
Finally, Shimano Alivio has become more affordable in response to the restructuring, with the Deore 10- and 11-speed groupsets taking the place previously occupied by this groupset. (In a whirlwind of Shimano news, there are also new batteries for electric bikes).
What are the new Shimano Deore groupsets called?
Just so we’re all on exactly the same page, here is a brief overview of the nomenclature of the new Shimano Deore groupset family.
- Shimano Deore M6100: 12-speed, 1x only
- Shimano Deore M5100: 11-speed, 1x and 2x options
- Shimano Deore M6100: 10-speed, 1x and 2x options
There are some shared components across each of these groupsets, and inter-compatibility in certain areas, but this should keep you on the right track when comparing things.
Shimano Deore M6100 groupset weights
| Component | Weight (grams) |
|---|---|
| Shimano Deore FC-M6100-1 crankset (170mm long, 30-tooth chainring) | 782 |
| Shimano Deore SM-BB52 bottom bracket (with spacers) | 89 |
| Shimano Deore RD-M6100-SGS rear derailleur | 320 |
| Shimano Deore CN-M6100 chain (full factory length plus master link) | 280 |
| Shimano Deore CS-M6100-12 cassette | 596 |
| Shimano Deore SL-M6100-R shifter (without display, with bar clamp and internal cable) | 134 |
| Shimano Deore SL-M6100-R I-SPEC shifter (without display, with internal cable) | 130 |
| Shimano Deore BL-M6100 brake lever | 124 |
| Shimano Deore BR-M6120 brake caliper with 1,000mm hose | 179 |
| Shimano Deore BR-M6120 brake caliper with 1,700mm hose | 195 |
Full groupset weights are tricky to pin down because bike-specific components and personal choice parts (such as crank length, bottom bracket type or disc rotor size) can increase or decrease a part's weight by a few grams.
The Deore M6100 kit Technical Editor Alex has bolted to his bike weighs a total of 2,823g including shifter, rear derailleur, cassette, chain, cranks plus chainring, bottom bracket and 4-piston brakes and levers.
Shimano 12-speed SLX groupset with the equivalent components weighs approximately 2,588g, 235g lighter. Similarly, Shimano's XT 12-speed groupset with equivalent components is 408g lighter, weighing around 2,415g in total.
Please be mindful these figures are guides only and specific groupset weights can vary.
1x finally supported at a Deore level
Shimano Deore M6100 crankset options
As the centrepiece of any groupset, we’ll start with the crankset.
The top-tier 12-speed Deore M6100 groupset is dedicated to a 1x setup. This is the first time 1x has been officially supported by Shimano at a Deore level.*
The crankset (FC-M6100) is available with 30 or 32t chainrings, though the cranks use the same direct-mount spiderless chainring as all other 12-speed Shimano groupsets, so more options are available.
Though it looks like the chainrings can be removed from the ‘spider’, these are not designed to be removed, and spares will not be available.
The crankset is available in 170 or 175mm crank lengths and with the following chainline options:
- FC-M6100-1: 52.0mm chainline for 142/148mm standard/Boost hubs. 172mm Q-factor
- FC-M6120-1: 55.0mm chainline for 148mm Boost hubs. 178mm Q-factor
- FC-M6130-1: 56.5mm chainline for 157mm SuperBoost hubs. 181mm Q-factor
As expected, Shimano has stuck steadfastly with its longstanding HollowTech II design for the new groupset, and the crankset is only available with a 24mm spindle.
Interesting tech aside, the new crankset looks great – it has a much more premium feel than the outgoing generation, in our opinion, and the glittery iridescent Deore logo is very handsome.
*As a caveat to all of this, two non-series Deore-level 12-speed cranksets – the FC-MT610 and FC-MT510 – are also available. We assume these are intended to be used on bikes equipped with SLX and above 12-speed groupsets that are trying to hit a lower price point.
Shimano Deore M5100 and M4100 crankset options
For the 11-speed Deore M5100 and 10-speed Deore M4100 groupsets, both 1x and 2x options are available.
The 1x option is available at both levels with either a 30 or 32t chainring. These mount using a standard Shimano asymmetric 96mm BCD (bolt circle diameter).
For 11-speed, it is recommended this is paired with Shimano’s wide-range 11-51t cassette (more on that below), and on 10-speed the 11-46t cassette is your best option.
For riders who prefer a double setup, a single 26-36t option is available at both levels. Shimano recommends this is paired with an 11-42 cassette, giving the option of some truly low gearing.
All of the above options are available for both Boost and standard chainlines.
Hyperglide+ shifts down to Deore
Deore M6100 chain and cassette options
The Deore M6100 chain (CN-M6100) and cassette (CS-M6100) get the same Hyperglide+ profiling as seen on all 12-speed Shimano mountain bike groupsets.
Hyperglide+ is a system of clever forming, ramps and pins on the cassette and chain that are designed to aid shifting both up and down the cassette, particularly when under high loads.
When shifting down the cassette – i.e. onto a smaller sprocket – the Hyperglide+ ramps temporarily ‘hold’ the chain in place before it fully engages with the smaller cog. This is designed to provide a much smoother transition between gears.
In testing, we have found the system to be very effective, with the smoothness of shifting into a higher gear under load very noticeable.
To see this tech at a Deore level is probably the most notable highlight of the launch.
The cassette itself is constructed from 12 pinned and stamped-steel cogs. SLX and above get a mix of more exotic materials and composite carriers to reduce weight. The cassette is available in one single 10-51t option.
As mentioned before, the new cassette uses Shimano’s Micro Spline freehub body. This replaced Shimano’s long-standing HG-style freehub body with the launch of XTR M9100 back in 2018.
Its overall dimensions are slimmer, allowing for the use of a 10t smallest cog, extending range on 1x drivetrains.
Micro Spline was originally mired in some controversy because it was a closed-standard that only certain hub manufacturers, licensed by Shimano, had the rights to produce. This severely limited options for consumers.
However, with Micro Spline being adopted with SLX and XT – and thus, more affordable price points – the standard was opened up to most OEM manufacturers in late 2019.
The addition of these more affordable 12-speed components will be a tempting option for riders with higher-tier groupsets looking to replace worn-out components on a budget, with little compromise in terms of performance.
Shimano Deore M5100 and M4100 10- and 11-speed cassette options
Shimano has introduced a number of interesting cassette options on the 10- and 11-speed side of things. All of these cassettes still use a standard HG freehub.
Most notable is the introduction of an 11-51t 11-speed Deore-level cassette. This is designed to be used primarily with the 1x version of the M5100 drivetrain and will give you most of the range of the 12-speed drivetrain in a slightly less close-spaced ratio.
For riders currently using an 11-speed drivetrain, this will also offer a tempting – albeit not officially compatible – upgrade option.
There are loads of aftermarket options that cover this kind of range, but this is the first official one from Shimano.
While it’s likely most current 11-speed derailleurs won't have the tooth capacity to work with this as stock, with the addition of something like the Wolf Tooth GoatLink, you could get super-wide gearing on a budget.
We look forward to seeing all the various mashups this opens up appearing online in the near future...
If you prefer a 2x drivetrain, an 11-42 cassette is also available.
For 10-speed M5100, there is now the option of an 11-46t cassette for a 1x setup and an 11-42t cassette for a 2x setup.
Lots of rear derailleur options – and the front derailleur ain’t dead yet
Shimano Deore M6100 RD-M6100-SGS rear derailleur
A single derailleur option (RD-M6100-SGS) is available for the 12-speed Deore groupset.
From the outside, there looks to be little that separates this derailleur from higher tier options – the overall shape is almost identical to SLX and XT, and features such as the adjustable Shadow+ clutch are retained.
As is common with lower-end Shimano groupsets, it’s likely that one or both of the pulley wheels will spin on bushings rather than sealed bearings, and less exotic materials will be used, pushing up weight, but that looks to be about it.
The cable pull ratio for 12-speed Deore M6100 is identical to SLX and XT, so this presents a more affordable replacement option for riders on those groupsets.
Lastly, as with the crankset, the derailleur looks great. Its overall finish belies its entry-level price point and we’ll say it again: that sparkly lettering is lovely.
It’s worth noting that Shimano’s direct-mount derailleur hanger design seems to have been totally abandoned with its 12-speed mountain bike groupsets (though it has been retained on M5100 and M4100, as well as its road and GRX groupsets).
Shimano Deore M5100 and M4100 derailleur options
There are more rear derailleur options for M5100 and M4100 that are best broken down by the individual models.
The RD-M4120-SGS and RD-M5120-SGS rear derailleurs are compatible with both 11- and 10-speed cassettes.
The cable pull ratio between 11- and 10-speed Shimano mountain bike groupsets is very similar, meaning that, according to Shimano either of these derailleurs will "work perfectly as an upgrade option for existing shifters on 10- and 11-speed bikes".
Shimano Deore 11-speed RD-M5100-SGS rear derailleur
The RD-M5100-SGS rear derailleur is dedicated to the 1x version of the 11-speed Deore M5100 groupset, and is designed to be paired solely with the aforementioned 11-51t cassette.
The overall geometry is designed to suit the more extreme chainline experienced with a 1x drivetrain. It is doubtful the derailleur would have the capacity to work with a double crankset, and this certainly isn’t officially supported by Shimano.
Shimano Deore RD-M5120-SGS rear derailleur
The RD-M5120-SGS rear derailleur is designed to be paired with either a double crankset and the 11-42 cassette, or a 1x crankset and the 11-46 cassette. It retains the overall look of Shimano's previous generation mountain bike groupsets.
This derailleur is said to work with both 10- and 11-speed cassettes.
Shimano Deore RD-M4120-SGS rear derailleur
Finally, there is the Deore RD-M4120-SGS. This is the most affordable derailleur option in the Deore lineup, and will work with either 2x11 or 2x10 drivetrains. It does not feature a clutch.
Deore M5100 and M4100 front derailleur
Front derailleurs on mountain bikes – remember them?
Shimano certainly does, offering a double drivetrain option in some form or another all the way up to an XTR level. This is in stark contrast to SRAM, which publicly dropped front derailleurs from its core mountain bike groupset line back in 2016.
Deore sticks with the trend, offering a front derailleur at both an M5100 and M4100 level. The press release for the groupset does not disclose what the actual difference between these two levels amounts to.
All of the derailleurs are available in band-on (FC-M5/4100-M), direct-mount (FC-M5/4100-D) and bottom bracket (FC-M5/4100-E) options, with each officially able to clear a 2.3in-wide tyre.
As a reminder, there is no double option for 12-speed Deore. Riders will have to look to SLX M7100 for the most affordable 2x12 option in Shimano’s lineup.
Deore rides the Servo Wave
The Deore M6100 brakes retain Shimao's Servo Wave technology and get the option of two- or four-piston brakes, as well as the new lever design first introduced with XTR.
The M6100 calipers and levers are shared across both the 12-speed and 11-speed Deore groupsets. A separate non-series brakeset is dedicated to the 10-speed groupset.
Servo Wave is a longstanding design that was first seen approximately one zillion years ago when rim brakes were still commonly used on mountain bikes.
In brief, Servo Wave makes the relationship between lever and brake pad movement non-linear.
In the initial part of the lever stroke, the pads move together quickly to meet the rotor. Part of the way through the stroke, this rate of closure slows, trading speed for increased power and modulation.
This technology was first introduced at a Deore level with M6000.
Also for the first time at a Deore level, both a two-piston (BR-M6100) and four-piston (BR-M6120) caliper option is available.
The four-piston caliper will give the maximum power possible, as well as improved heat management, for enduro or trail riders, and the two-piston option will offer a slight reduction in weight.
The same brake lever (BL-M6100) is shared across both brakes and includes the nifty nubbin on the outside edge of the lever that braces the body of the reservoir against the handlebar. This was first seen on XTR M9100 and really helps improve feel at the lever.
The M4100-level brake lever and caliper (MT410 or MT420) is a non-series component. It is also available in a two- or four-piston design, but loses out on the Servo Wave technology.
i-Spec EV for all
The shifters on all Deore levers adopts Shimano’s i-Spec EV standard. This allows you to mount shifters to the brake levers and really helps to neaten up a cockpit. The same system is used on Shimano's other 12-speed groupsets.
The system allows for up to 14mm of lateral movement and 10 degrees of rotational movement of the shifters. In comparison, SLX and above allows for up to 20 degrees of rotational movement.
The 10- and 11-speed shifters are almost identical, the key difference being that there is a front shifter option.
The same shifter (SL-M5100-L) is used for both groupsets and features Shimano’s single-lever design.
Rounding out the bar controls is the non-series SL-MT500 dropper post control lever. This looks to be largely similar to the existing SL-MT800 lever, but doesn’t have the window cut-outs on the barrel adjuster or lever body.
Shimano Deore M6100, M5100 and M4100 pricing
Pricing Shimano groupsets is a funny old business – street pricing in Europe never matches the RRP, whereas in North America, sellers are bound to sell the groupset at RRP.
Likewise, some distributors offer ‘complete groupset’ prices, whereas others list the prices of individual products.
To avoid any confusion, we have published the pricing for each individual component as supplied by UK distributor, Madison, Shimano's press office in the USA and select M6100 pricing direct from Shimano Australia.
As we receive pricing information for other territories and the groupset appears at various retailers, we will update this table. In the meantime, refer to your favourite online retailer or friendly local bike shop for up-to-date pricing.
The prices quoted for the brakes are for one complete brake system (i.e., one fully bled brake, caliper and lever for either the front or rear).
