A drive system for a vehicle, comprising: a drive chain having a plurality of links (100, 102;904,910; 1904,1910) and a centerline (120;980; 1980); and a chain ring having a plurality of teeth (304;400,408; 1400,1408)joined to one another and serially arranged; wherein each of the plurality of teeth (304;400,408;1400,1408;) is configured to interfit with a respective one of the plurality of links (100, 102; 904,910; 1904, 1910) of the drive chain ; wherein each of the plurality of teeth has a top surface (604;920;1920) and a base (608;658;1658); wherein each of the plurality of teeth (304; 400,408;1400,1408) has a thickness , the thickness of each of the plurality of teeth at its respective thickest point (608,658;1608,1658) being substantially identical; wherein, when the drive chain and chain ring are interfitted with one another, the bases (608;658;1608,1658) of the teeth (304;400,408;1400,1408) are laterally asymmetrically arranged about the centerline (120;980;1980) of the drive chain ; and wherein, when the drive chain and the chain ring are interfitted with one another, the top surfaces (604;920;1920) of the teeth (304;400,408;1400,1408) are laterally asymmetrically arranged about the centerline (120;980;1980) of that drive chain , characterized in that , when in operative position, each centerline (950, 952;1962,1952) of each top surface (604;920,922;1920;1922,) of each tooth (304;400,408;1400,1408) is offset laterally from the centerline (980; 1980) of the drive chain in the same direction. a drive chain having a plurality of links (100, 102;904,910; 1904,1910) and a centerline (120;980; 1980); and a chain ring having a plurality of teeth (304;400,408; 1400,1408)joined to one another and serially arranged; wherein each of the plurality of teeth (304;400,408;1400,1408;) is configured to interfit with a respective one of the plurality of links (100, 102; 904,910; 1904, 1910) of the drive chain ; wherein each of the plurality of teeth has a top surface (604;920;1920) and a base (608;658;1658); wherein each of the plurality of teeth (304; 400,408;1400,1408) has a thickness , the thickness of each of the plurality of teeth at its respective thickest point (608,658;1608,1658) being substantially identical; wherein, when the drive chain and chain ring are interfitted with one another, the bases (608;658;1608,1658) of the teeth (304;400,408;1400,1408) are laterally asymmetrically arranged about the centerline (120;980;1980) of the drive chain ; and wherein, when the drive chain and the chain ring are interfitted with one another, the top surfaces (604;920;1920) of the teeth (304;400,408;1400,1408) are laterally asymmetrically arranged about the centerline (120;980;1980) of that drive chain , wherein each of the plurality of teeth (304;400,408;1400,1408;) is configured to interfit with a respective one of the plurality of links (100, 102; 904,910; 1904, 1910) of the drive chain ; wherein each of the plurality of teeth has a top surface (604;920;1920) and a base (608;658;1658); wherein each of the plurality of teeth (304; 400,408;1400,1408) has a thickness , the thickness of each of the plurality of teeth at its respective thickest point (608,658;1608,1658) being substantially identical; wherein, when the drive chain and chain ring are interfitted with one another, the bases (608;658;1608,1658) of the teeth (304;400,408;1400,1408) are laterally asymmetrically arranged about the centerline (120;980;1980) of the drive chain ; and wherein, when the drive chain and the chain ring are interfitted with one another, the top surfaces (604;920;1920) of the teeth (304;400,408;1400,1408) are laterally asymmetrically arranged about the centerline (120;980;1980) of that drive chain , <EOS>