Specifications of the rear hub: 
Brand: Shimano
Model: FH-TX505 Tourney
Color: Zwart
Number of spoke holes: 32GTS
Type of brake: Disc (Centerlock)
Number of gears: HG Body 35 MM = suitable for old type Race (max 10 speed) and all MTB cassettes.
Type of axle: Uitvalas
Axle included: Yes, quick release
Type of bearings: Ball bearings
Average weight (GR): 386
Intended use: MTB - Tour
 
Data for spoke length calculations using the Sapim spoke size calculator: 
Total length of the hub (MM): 135
Non-gear side (MM): 32
Gear side (MM): 44
Hub diameter non-gear side (MM): 44
Hub diameter gear side (MM): 44
 
Link to spoke calculator: www.sapim.be/spoke-calculator