Rim Specifications:    
Brand:    Rigida - Ryde
Model:    Andra 321
Color:    Black
Size (Inch/MM):    584X21C
External width (MM):    26
Internal width (MM):    21
Average weight (GR):    594
Material:    Aluminium
Single-walled / Double-walled:    Double-walled
Single eyelets / Double eyelets:    No eyelets
Number of spoke holes:    32GTS
Spoke nipple size:    14G
Brake surface present:    No
    
Data for spoke length calculations using the Sapim spoke size calculator:    
Internal diameter of the rim (MM *Not ERD*):    555
Rim thickness (MM):    3
Number of spokes in the wheel:    32
Number of crossings gear side: of your choice    
Number of crossing non-gear side: of your choice    
    
Link to spoke calculator: www.sapim.be/spoke-calculator