Best MTB Cranksets and How to Choose the Right Fit (2026)
Four mountain bike cranksets from Shimano, SRAM and Race Face, and the length, chainring and bottom bracket details that decide fit.
What a Crankset Does
The crankset turns your pedaling into drive: it includes the crank arms, spindle and chainring. Upgrading can save weight, improve stiffness or let you change crank length and gearing. But cranksets are full of compatibility details: spindle and bottom bracket, chainline (Boost or non-Boost), chainring mount and crank length. Get those right and the upgrade is straightforward. Here are four MTB cranksets from Shimano, SRAM and Race Face.
Shimano Deore FC-M6100
Best value crankset
- 12-speed 1x
- Aluminum arms
- 170mm / 32T shown
Race Face Aeffect
Best for trail and enduro
- Tough alloy arms
- Multiple lengths
- Popular aftermarket crank
SRAM SX Eagle
Best SRAM budget crank
- For Eagle 12-speed
- PowerSpline bottom bracket
- Affordable
MTB Cranksets Compared
| Crankset | Material | Notes |
|---|---|---|
| Shimano Deore FC-M6100 | Aluminum | 12-speed 1x, chainring included (32T shown) |
| Shimano SLX FC-M7100 | Aluminum | Arms only; chainring sold separately |
| SRAM SX Eagle | Alloy | PowerSpline bottom bracket |
| Race Face Aeffect | Alloy | Several arm lengths; check chainring and BB needs |
The Best MTB Cranksets
1. Shimano Deore FC-M6100
The Deore M6100 crankset has aluminum arms and is designed for Shimano's 12-speed 1x drivetrains. This listing is 170mm with a 32-tooth chainring.
Good to Know
- Great value
- Chainring included
Watch Out For
- Check Boost chainline and bottom bracket
2. Race Face Aeffect
The Aeffect is Race Face's tough, affordable trail crank. This listing is 165mm arms without a chainring, a popular length for pedal clearance on trail bikes.
Check Price on Amazon3. SRAM SX Eagle
SX Eagle cranks are SRAM's entry-level 12-speed option, compatible with PowerSpline bottom brackets.
Check Price on Amazon4. Shimano SLX FC-M7100
The SLX M7100 1x crank arms are a step up from Deore. The chainring is sold separately, so you can pick your tooth count.
Check Price on AmazonHow to Choose an MTB Crankset
Crank Length
| Length | Effect |
|---|---|
| 160–165mm | More pedal clearance, quicker spin, suits shorter riders |
| 170mm | The common middle ground |
| 175mm | More leverage, suits taller riders, less clearance |
Chainring Size
On 1x 12-speed bikes, 30 to 34 teeth is typical. Go smaller for steep climbing, larger for speed. Check the maximum ring size your frame allows.
Spindle and Bottom Bracket
Shimano uses its Hollowtech II system; SRAM uses DUB or PowerSpline depending on the crank; Race Face uses its own spindles. Your bottom bracket must match both the crank spindle and your frame's shell.
Chainline
Most modern trail bikes use Boost spacing (often a 52mm chainline). Choose a crank or chainring offset that matches.
Chainring Mount
Direct-mount rings attach to the crank without a spider; check the ring standard for your crank.
Installation Tips
- Confirm bottom bracket compatibility first.
- Grease the spindle and threads.
- Use the correct preload and torque values.
- Check chainline and shifting across the cassette.
A bike shop can help with bottom bracket tools and chainline checks. Pair your crank with matching shifters and grippy MTB pedals.
Frequently Asked Questions
What crank length should I use on a mountain bike?
Many riders use 165 to 175mm. Shorter cranks (160–170mm) give more pedal clearance and suit shorter riders; longer cranks give more leverage.
What chainring size should I run?
On 1x 12-speed bikes, 30 to 34 teeth is common. Smaller rings make climbing easier; larger rings give higher top speed.
Will any crankset fit my bike?
No. The crank spindle must match your bottom bracket and frame, and the chainline must suit your frame (for example, Boost spacing).
What's the difference between Deore, SLX and XT cranks?
Higher tiers are lighter with refined finishes. All are designed for Shimano 12-speed drivetrains.
Do I need a new bottom bracket?
Often, if you switch brands or spindle standards. Check compatibility before buying.