Specifications of the rear hub: 

Brand: BQ
Model: BQ-RH30004
Color: Black
Number of spoke holes: 36GTS
Type of brake: Disc (6 bolts)
Number of gears: HG Body 36.85 MM (HG 11) = suitable for all cassettes (possibly with the use of spacer(s))
Freewheel system:    Pallen (6)
Points of engagement:    60
Type of axle: Thru axle Ø 12 MM
Axle included: No
Type of bearings: Industrial bearings
Average weight (GR): 340
Intended use: MTB - Tour
 
Data for spoke length calculations using the Sapim spoke size calculator: 
Total length of the hub (MM): 142
Non-gear side (MM): 35
Gear side (MM): 52
Hub diameter non-gear side (MM): 58
Hub diameter gear side (MM): 58
 
Link to spoke calculator: www.sapim.be/spoke-calculator