Q-factor and stance width decide how far apart your feet sit while you pedal — a setup detail most riders never touch, but one that quietly shapes how the knee tracks and how comfortable long rides feel. You work directly with me, Lloyd Thomas.
What Q-factor and stance width are
Q-factor is the horizontal distance between the outer faces of the two crank arms — how far apart the cranks themselves hold your feet. Stance width is the rider-side result: the actual distance between your feet once pedals, cleats and any spacers are added on top. Q-factor is fixed by the cranks; stance width is where the fitting adjustments happen.
Why it matters for the knee
Cycling repeats the same leg movement thousands of times per ride, so the line the knee travels matters. Stance width influences whether the knee tracks cleanly over the foot or gets pushed slightly inward or outward. When the feet are held too wide or too narrow for how your hips and legs are built, the knee is nudged off its natural path — and small deviations, repeated that often, become discomfort.
How stance width is adjusted
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pedal choice and pedal axle length (some come in longer or shorter axles)
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cleat lateral position on the shoe
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pedal spacers or washers to widen slightly
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in some cases crank choice, which sets the underlying Q-factor
Narrower is not automatically better
There is a trend toward narrower stance, and for some riders it helps — but it is not a universal rule. The right stance width is simply the one that lets your knee track cleanly for your anatomy and your hips. That is a judgement made by watching you pedal under load, not by copying a number off someone else’s bike.