Rear hub thru-axle for human powered vehicle

A rear hub thru-axle for a human powered vehicle, the rear hub thru-axle comprising:

• a first axle portion having a first hollow interior passage defining a first interior diameter;
• and
• a second axle portion having a second hollow interior passage defining a second interior diameter,
• the first axle portion being connected to the second axle portion in an axial direction with respect to the rear hub thru-axle,
• the first interior diameter of the first hollow interior passage being larger than the second interior diameter of the second hollow interior passage,
• the first hollow interior passage of the first axle portion being configured to receive a battery, and
• the second hollow interior passage of the second axle portion being configured to receive a circuit board on which a wireless communication unit is mounted,
• the first axle portion having a first exterior surface defining a first exterior diameter and the second axle portion having a second exterior surface defining a second exterior diameter,
• the first exterior diameter being larger than the second exterior diameter,
• the second axle portion having an exterior thread for threadedly engaging with a fixing nut, or a fork or a frame,
• the second exterior surface being disposed between the first exterior surface and the exterior thread, and
• an axial length of the second exterior surface being longer than an axial length of the exterior thread.