Cranksets

Linker crankarm 170 mm

A single left crank arm, 170 mm, listed for single speed, mountain and road bikes. Handy when you only need to replace one arm.

What you get

Left crank arm
170 mm length
For single speed, MTB and road

Why the right crankset?

The number of teeth on your chainring decides how hard or easy your gears are. A standard crankset (for example 53/39) is made for fast, flat riding. A compact (for example 50/34) gives an easier climbing gear and suits most recreational riders better. On gravel you see 46/30 or 48/31, on MTB often a single ring of 30 to 36 teeth.

A single ring (1x) is simpler: no front derailleur, less weight and less chance of the chain dropping. The cost is bigger jumps between gears and a bigger cassette. Two rings (2x) give smaller steps and a wider total range.

When choosing, look at the BCD, the diameter of the circle on which the chainring bolts sit. On the road that is often 110 mm (four bolts, compact and standard) or 130 mm. On MTB 104 mm is common. The BCD decides which chainrings fit, and so how small or large you can go.

A second choice is the spindle. An old square taper spindle sits in many older bikes. Modern cranksets have external bearings with a 24 mm spindle, or 28.99 mm for SRAM DUB. That is stiffer, lighter and easier to maintain, but it only fits the right bottom bracket.

How the setups compare

The chainring combination decides what your bike is good at.

Setup	Chainrings	Suits	Downside
Standard	53/39 or 52/36	Fast, flat, racing	A hard easiest gear
Compact	50/34	Hilly and recreational	Less top speed on long descents
Gravel 2x	46/30, 48/31 or 48/32	Gravel and road, wide range	Needs a front derailleur
Gravel 1x	One ring of 38 to 44 teeth	Gravel, simple and sturdy	Bigger jumps, wider cassette
MTB 1x	One ring of 28 to 36 teeth	Off-road, climbing and descending	On the road: limited top end

Pair the chainring with a matching cassette or you lose the top or bottom of the range.

Choose it if

Your left arm is damaged and the rest of your crankset is fine
You want a 170 mm spare arm
Your crankset is worn or cracked, or the teeth have turned hook-shaped.
You want easier gears for the mountains or harder ones for fast riding.

Choose something else if

You need to replace the whole crankset: take a complete set
You do not know your bottom bracket or bearing type. Without that, you can easily order a crankset that does not fit.
You only want to replace the chainring: buy the ring separately, provided the BCD matches.

How to fit a crankset

Check the bottom bracket
Look at the width (68 or 73 mm) and bearing type of your bottom bracket. The crankset has to match.
Remove the old crank
Undo the crank bolt or the clamp with a hex key and pull the arm off with a crank puller.
Grease the spindle and slide the crank on
Grease the spindle lightly. Push the right arm with the chainrings through the bottom bracket and fit the left arm on the other side.
Tighten to the right torque
Tighten the bolts to the manufacturer’s figure, usually 12 to 15 Nm. Check after the first ride that everything is still tight.
Adjust the front derailleur
With two rings, reset the height and limit screws on the front derailleur. Finally turn the pedals and run through the gears.

Good to know

A crank arm only fits the right spindle (square taper, Octalink, ISIS or other). Check this against your current set
Both arms need the same length
Check the crank arm length. You normally ride 170 to 175 mm. A different length changes pedalling geometry, especially with shorter legs or knee problems.
Use the right adapters and bearings. A BB30 or PF30 bottom bracket needs a different spindle than a Shimano bearing in a standard shell.
Worn teeth stop a new chain from engaging well. Replace chainring, chain and cassette together where you can.
Do not overtighten bolts on carbon cranks: follow the stated torque.

What you get

Why the right crankset?

How the setups compare

Choose it if

Choose something else if

How to fit a crankset

Check the bottom bracket

Remove the old crank

Grease the spindle and slide the crank on

Tighten to the right torque

Adjust the front derailleur

Good to know

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