Specifications of the rear hub:
Brand: Shimano
Model: Nexus Inter 8 SG-C6001-8C
Color: Silver
Number of spoke holes: 36GTS
Type of brake: Coaster brake
Number of gears: 8S
Type of axle: Fixed axle 187 MM
Axle included: Yes, without nuts
Type of bearings: Ball bearings
Average weight (GR): 2044
Intended use: City

Data for spoke length calculations using the Sapim spoke size calculator:
Total length of the hub (MM): 131
Non-gear side (MM): 34
Gear side (MM): 40
Hub diameter non-gear side (MM): 92
Hub diameter gear side (MM): 92

Link to spoke calculator: www.sapim.be/spoke-calculator