When you're choosing parts for a bicycle drivetrain upgrade, the groupset is the decision that ties together your shifter, rear derailleur, cassette, and chain. These four Shimano kits cover the two questions most mountain bikers face: go 11-speed or 12-speed, and pick Deore or SLX. The listed prices run from $128.99 to $179.99.
Quick take: if your hub is Micro Spline and you want 12-speed, the Deore M6100 kit is the most direct path at the lowest listed price. If you're staying with an 11-speed drivetrain, the two Deore M5100 kits give you the same speed count and nearly the same price. If you want the SLX name and 12-speed, the SLX M7100 is the higher-priced option here.
Listed price comparison
| Product | Listed Price | Price Bar |
|---|---|---|
| New Shimano Deore M6100 12 Speed Micro Spline Drivetrain Groupset 51T MTB | $128.99 | |
| New SHIMANO Deore M5100 11 speed Drivetrain Groupset 42T/51T MTB | $129.88 | |
| Shimano DEORE 11 Speed M5100 4pcs Drivetrain Groupset 42T 51T | $129.99 | |
| Shimano SLX M7100 12 Speed Drivetrain Groupset 51T Micro Spline Cassette (OE | $179.99 |
The lowest listed price is $128.99, and the highest is $179.99, so the gap between the cheapest and most expensive kit is $51.00.
Decision matrix
| Consideration | Deore M5100 11-speed kits | Deore M6100 12-speed kit | SLX M7100 12-speed kit |
|---|---|---|---|
| Speeds | 11 | 12 | 12 |
| Cassette | 42T | 51T Micro Spline | 51T Micro Spline |
| Freehub notes | HG-style shifting | Micro Spline required | Micro Spline |
| Condition | New other (see details) | New other (see details) | New |
New SHIMANO Deore M5100 11 speed Drivetrain Groupset 42T/51T MTB
This 11-speed group is built around Shimano's Deore M5100 shifter and rear derailleur, and the kit also includes a cassette and chain. The listing notes compatibility with mountain bikes, trekking bikes, and downhill bikes, which gives it a wider stated fit than some of the other kits. The listed cassette is 42T, and the title also references 42T/51T, so you're getting the 11-speed Deore setup rather than a 12-speed range. The main limitation is the speed count: at 11 speeds, you get one fewer gear than the M6100 and SLX options in this comparison. If you're building an 11-speed drivetrain, this kit sits close to the other Deore M5100 group in price.
New Shimano Deore M6100 12 Speed Micro Spline Drivetrain Groupset 51T MTB
This is the lowest-priced item in the comparison. The kit covers the 12-speed M6100 shifter, M6100 51T cassette, rear derailleur, and chain, and the cassette is specifically a Micro Spline design. The listing explicitly notes that a Micro Spline hub is required, which makes this the most direct 12-speed route if your bike already has a Micro Spline freehub. The limitation is that you can't run the cassette on a standard HG freehub body, so your hub choice will decide whether this kit fits. For a 12-speed mountain bike build, this is the least expensive entry point in this group.
Shimano DEORE 11 Speed M5100 4pcs Drivetrain Groupset 42T 51T
This is the other 11-speed Deore M5100 kit. It pairs the M5100 shifter, rear derailleur, and 42T cassette with a Shimano HG601 11-speed chain, giving you a complete four-piece drivetrain package. The price is listed just above the M5100 kit above, so the two 11-speed Deore groups are essentially competing on packaging rather than a major price difference. The limitation is the same speed constraint: you're limited to 11 gears, and the listed cassette is the 42T version rather than the 51T version. If you want an 11-speed mountain bike drivetrain and the four-piece setup, this kit gives you a straightforward option.
Shimano SLX M7100 12 Speed Drivetrain Groupset 51T Micro Spline Cassette (OE
The highest-priced kit in this comparison is the SLX M7100 12-speed group. It brings the SLX M7100 shift lever and rear derailleur together with a 51T Micro Spline cassette, and the listing is marked as New and manufactured in Japan. It's positioned as a mountain bike groupset, and the Micro Spline cassette matches the same freehub requirement as the Deore M6100 12-speed kit. The limitation is the price: at $179.99, it costs $51.00 more than the Deore M6100 kit, and both list a 51T Micro Spline cassette in a 12-speed configuration. The main stated difference in the listing is the SLX component line rather than a larger gear range.
Final recommendation by use case
For a 12-speed Micro Spline build, the Deore M6100 kit is the lowest-priced way to get the full group in this comparison. For an 11-speed build, either Deore M5100 kit works, and they're nearly identical in listed price. For a 12-speed drivetrain in the SLX family, the SLX M7100 kit is the higher-priced option that matches that need.
