Q Factor Is the distance between the outside of one crank arm to the outside of the opposite crank arm. This affects how far apart your feet and legs are when cycling.
It’s important to note the spindle length when buying a new set of pedals. Spindle length is measured from the center of the pedal body to where the pedal spindle meets the crank arm.
For road pedals, spindle lengths in the mid- to high-50 mms are common
You will see Spindle length being referred to as Q Factor in many power meter pedal specifications. We refer to spindle length as Q Factor in our comparison chart.