There’s been a lot of discussion around shorter crank arms, and for good reason. John Cobb was an early pioneer in this area, pushing past the industry’s one-size-fits-all approach to offer variable crank lengths. Today, shorter cranks are a proven tool for aerodynamics, safety, and comfort.

Aerodynamics: How Low Is Too Low?

In wind tunnel testing, many riders couldn’t get low in the front because their thighs hit their torso. Shorter cranks solved this, unlocking faster and more aerodynamic positions. Whether you’re racing Ironman or time trials, shorter cranks help maximize your aero gains. Before spending hundreds on helmets and gear, make sure your position is optimized first.

Performance Tuning

Do shorter cranks cost you power? Research and rider feedback show that they don’t. Your foot travels a shorter distance per pedal stroke, with no measurable loss of efficiency. Riders often swap to a larger chainring to keep the pedal stroke “feeling” familiar. The key: shorter cranks let you stay in the most efficient muscle range while improving aerodynamics.

Solving Toe Overlap

For smaller riders, especially under 5’1”, toe overlap is a serious safety issue. When your shoe hits the front wheel during a turn, it can quickly lead to crashes. Switching to 145–155mm cranks removes this interference, making your bike safer and more comfortable to ride.

Hip & Knee Joint Health

If you’ve had a hip or knee replacement, or struggle with bone spurs, shorter cranks reduce the required range of motion. This makes cycling smoother and more enjoyable, without sacrificing leverage or performance. For fitters, it’s another tool to increase rider comfort.

Better Breathing

Shorter cranks also improve breathing. Many riders, whether carrying extra weight or just shorter in stature, struggle with thighs pressing into the stomach. This compresses the diaphragm and limits power. With shorter cranks, the legs clear the torso, letting you breathe deeper and ride more efficiently.

Shorter cranks aren’t just a trend, they’re a proven solution for aerodynamics, safety, joint comfort, and breathing. Choosing the right crank length is one of the most impactful fit decisions you can make for both speed and long-term comfort.