Everything you want to know about the Q Factor

As we all know, Q factor is the person who equips tuxedo-clad Special Agents with nifty double-0 gadgets as he chases after villains. Wait, no, that’s not right… In the world of cycling, the Q factor refers to the width of the crank arms. More specifically, the lateral distance between the outside of the crank arms at the point where the pedal spindles affix.

The name is actually derived from the word “Quack,” referencing the waddling gait of a duck. And no, I’m not joking this time. Cycling legend Grant Peterson coined the term during his time with Bridgestone Bicycles.

Q factor is part of the equation that dictates the width of one’s pedalling stance and can impact both pedalling mechanics and overall bike fit. But the Q factor is not the sole component of a rider’s stance: it is a starting point. Ultimately, the width of your feet is also affected by pedal type, spindle length, cleat position and shoe design.

Differing Dimensions