Sprocket support body

A sprocket support body configured to be rotatably mounted on a hub axle of a bicycle hub assembly about a rotational center axis of the bicycle hub assembly, the sprocket support body comprising:

• a base support having a first axial end portion and a second axial end portion;
• at least ten external spline teeth provided on the first axial end portion of the base support and configured to engage with a bicycle rear sprocket assembly, each of the at least ten external spline teeth having an external-spline driving surface and an external-spline non-driving surface, the at least ten external spline teeth being integrally formed as a one-piece unitary member;
• and
• a plurality of helical external spline teeth provided on the second axial end portion of the base support;
• the at least ten external spline teeth including a plurality of external-spline driving surfaces to receive a driving rotational force from the bicycle rear sprocket assembly during pedaling;
• the plurality of external-spline driving surfaces each including:
• a radially outermost edge;
• a radially innermost edge;
• and
• a radial length defined from the radially outermost edge to the radially innermost edge;
• a total of the radial lengths of the plurality of external-spline driving surfaces being equal to or larger than 7 mm;
• at least one external-spline driving surface of the plurality of external-spline driving surfaces having a first external-spline-surface angle defined between the at least one external-spline driving surface of the plurality of external-spline driving surfaces and a first radial line extending from the rotational center axis to the radially outermost edge of the at least one external-spline driving surface of the plurality of external-spline driving surfaces;
• the first external-spline-surface angle ranging from 0 degree to 10 degrees;
• at least nine external spline teeth of the at least ten external spline teeth each having a same spline profile that continuously extends along an entire length of each of the at least nine external spline teeth when viewed along the rotational axis;
• the sprocket support body including a larger-diameter part and an axially sprocket abutment surface provided on the larger-diameter part;
• a groove being provided between the larger-diameter part and the at least ten external spline teeth in an axial direction of the sprocket support body;
• the groove extends continuously about an entire circumference of the sprocket support body;
• a total number of the at least ten external spline teeth being larger than a total number of the plurality of helical external spline teeth,
• the sprocket support body including a flange extending radially outwardly from the base support,
• the flange being provided between the larger-diameter part and the plurality of helical external spline teeth in the axial direction,
• the flange extending radially outward beyond a radially outermost surface of the larger-diameter part, and
• the flange having an outer portion that extends in the axial direction away from the larger-diameter part and toward the plurality of helical external spline teeth.