Choosing the right crank size is essential for achieving a more efficient, powerful, and comfortable ride. Whether you're a road cyclist, gravel rider, or endurance adventurer, crank arm length can affect your cadence, knee health, and power output. But how do you figure out what size is right for you? Let’s break it down.
How Do I Know What Size Crankset to Get?
Start by identifying your riding discipline and body mechanics. Most road bikes come standard with 170mm–175mm cranks, but many gravel and endurance riders benefit from shorter options (165mm–170mm) for better cadence and joint health. Riders with longer legs may benefit from longer crank arms, but it's not just about height—it's also about fit and pedaling style.
How Do I Know What Cranks Will Fit My Bike?
Compatibility is key. Cranksets need to match your bike’s bottom bracket type (like BSA, BB30, or PressFit) and your drivetrain configuration (1x or 2x, number of chainrings, etc.). Check your bike’s specs or consult with your manufacturer—or trust QO BIKE’s compatibility guide to choose the right crankset for your frame.
How Do You Know the Size of a Crank?
Crank size refers to the length of the crank arm, measured in millimeters from the center of the bottom bracket to the center of the pedal hole. Common sizes range from 165mm to 175mm, with most gravel riders leaning toward the shorter end of the spectrum for better control and cadence.
How Do You Calculate Crank Length?
There’s no one-size-fits-all formula, but a good starting point is measuring your inseam length (in cm) and multiplying it by 0.216. For example, a rider with an 80cm inseam might be well-suited to 172.5mm cranks. However, biomechanics, flexibility, and riding goals all play a role—bike fitting is always the most accurate method.
Are Longer or Shorter Cranks Better?
It depends on your goals.
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Shorter cranks (165mm–170mm) allow for higher cadence, reduce knee stress, and improve clearance—ideal for gravel and endurance riders.
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Longer cranks (172.5mm–175mm+) can generate more torque and may suit taller riders or sprinters who prefer slower, more powerful strokes.
Ultimately, comfort and efficiency are more important than crank length alone.
Get the Crankset That Works With You
At QO, we offer high-performance carbon cranksets in multiple sizes and configurations—designed to fit you, your bike, and the way you ride. Choosing the right crank length isn’t just about measurements; it’s about optimizing every pedal stroke for speed, control, and comfort.
