Adaptable lightweight and strong and with the latest quarq technology elsa r packs a four pronged punch to elevate bike and rider performance the lightweight spider houses integrated electronics a cr2032 battery led indicator and visible ant id power balance captures left and right drive strokes omnical gives you a choice of chainrings with no compromise on accuracy exogram hollow carbon crank arms minimize weight and maximize speed with lengths of 1625 1775mm elsa r can take a