Interesting! I have no problem achieving KOPS because my lower legs are so much longer than my upper legs. I'm 6 feet, 35.5" cycling inseam - and have an extra 3 inches between my calf and ankle. So my upper leg / knee falls behind the pedal spindle easier than if my upper leg was longer (if that makes sense).
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'11 Time NXR Instinct / '79 Paris Sport by Moulton