"The KS-3 is an internal gear box inside the bottom bracket. Shifting between the three gears takes place by pedaling backwards at an angle of sixty degrees. This cable free shifting system is exclusively in the Strida EVO KS-3 version. The three speed gear ratios are 78.7%, 100% and 125.7%. Thanks to shifting via backwards pedaling, the system does not needs cables or shifters, making the Strida KS-3 very clean. This new shifting system weighs less than a standard 3-speed gear hub. Total weight of the bike is just 12.5 kilograms."