25-406 (20" x 1.75) Aluminium, double wall spoke pattern without kinks (internally punched), for e-bikes/electric drive and mounting of large diameter hubs, suitable for highest loads Outer width 31.4 mm, Inner width 25.0 mm, Height 21.0 mm DV Item Article Version Double wall Brake mount Hub Disc - 5-hole , Disc - 6-hole , Disc - Center Lock , Roller Brake , Drum Brake , no mount Brake compatibility Rim universal Brake flank yes E-bike type ready ERD 600 mm ETRTO 25-406 Color Brake flank silver Rim outer width 31 mm Rim height 21 mm Rim inner width 25 mm For wheel yes Main color black Double wall shape symmetrical Wheel size 20 " Spoke hole internally punched Spoke hole quantity 36 holes Spoke hole diameter for 2.00 mm Valve type Dunlop (DV) , Schrader (AV) Wear indicator no max. Spoke tension 1,400 Nm