Riders and workshops replacing the cranks on a 2x9 Shimano mountain bike, or rebuilding a budget hardtail with fresh, reliable parts.
The Shimano FC-MT210-B2 is a 2 x 9-speed crankset from the Altus family, with a 36-22T pair of chainrings. The small ring gives you an easy climbing gear, while the 36 covers everything from fire roads to the ride home.
It's a 2-piece design, with the axle joined to the drive-side arm and running in an outboard bottom bracket. The 170 mm anodised aluminium arms suit most riders, and Shimano's HYPERDRIVE chainrings help the front shift happen cleanly.
The B2 version has a 51.8 mm chain line and a 176 mm Q-factor. It needs a Shimano outboard bottom bracket such as the BB-MT501 for threaded frames or the BB-MT500-PA for press-fit frames, and it runs a 9-speed HG chain. The bottom bracket isn't included.
36-22T double
Wide gear range with an easy climbing ring.
170 mm arms
A common MTB crank length that suits most riders.
2-piece outboard design
Stiffer and simpler than square taper.
HYPERDRIVE shifting
Smooth, dependable front shifts.
51.8 mm chain line
The B2 chain line, check it matches your bike.
Crankset
Fit and compatibility
In the box
HYPERDRIVE chainrings
Shimano's shaped and ramped chainrings for smooth, reliable front shifts.
2-piece crankset
The axle is fixed to the drive-side arm and runs in outboard bearings, a stiffer and simpler setup than older square-taper cranks.
Great for
Maybe not for
Needs a Shimano 24 mm outboard bottom bracket: BB-MT501 for threaded 68/73 mm shells or BB-MT500-PA for press-fit. Runs a 9-speed HG chain with a 2x front derailleur. The B2 has a 51.8 mm chain line, while the FC-MT210-2 has 48.8 mm, so match the one your bike came with. Pedals use a standard 9/16 inch thread.
Check the chain line first
The B2 and standard MT210-2 look identical but sit the rings in different places. If your bike came with a 51.8 mm chain line crank (often on Boost frames), this is the one. If you're not sure, bring the bike in and we'll check before you buy.
Installing a 2-piece crank
Slide the axle through the bottom bracket, fit the left arm, then snug the preload cap by hand before tightening the two pinch bolts evenly. Too much preload makes the bearings bind, so just take out the side-to-side play.
