Specifications of the front hub:
Brand: Shimano
Model: HB-RS400
Color: Black
Number of spoke holes: 32GTS
Type of brake: Rim brake
Type of axle: Drop axle
Axle included: Yes, quick release
Type of bearings: Ball bearings
Average weight (GR): 149
Intended use: Race

Data for spoke length calculations using the Sapim spoke size calculator:
Total length of the hub (MM): 100
Non-gear side (MM): 15
Gear side (MM): 15
Hub diameter non-gear side (MM): 38
Hub diameter gear side (MM): 38

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