Rim Specifications:
Brand: Rigida - Ryde
Model: V38
Color: Black
Size (Inch/MM):  28 x 1 1/2" / 635
External width (MM): 38,5
Internal width (MM): 25
Weight (GR): 708
Material: Aluminium
Single-walled / Double-walled: Single-walled
Single eyelets / Double eyelets: No eyelets
Number of spoke holes: 36
Spoke nipple size: 13
Brake surface present: No

Data for spoke length calculations using the Sapim spoke size calculator:

Internal diameter of the rim (MM *Not ERD*): 616

Rim thickness (MM): 2

Number of spokes in the wheel: 36

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