Chainring SAMOX E-bike Narrow wide BCD104 steel black. 38T.

Narrow wide chainring 38 teeth Fits 3/32", 11/128" chains 4-bolt mounting Color: Black BCD / cross bolt circle diameter: 104mm Weight: 170g Measuring bolt circle diameter on chainrings For 4-bolt models: measure the distance between adjacent bolt holes For 5-bolt models: generally use the provided measurement chart for reference Number of bolts on chainring | Distance between two adjacent holes | Cross bolt circle diameter (PCD/BCD) --- | --- | --- 4 | 45.3mm (1.78 inch) | 64mm 4 | 56.6mm (2.23 inch) | 80mm 4 | 62.2mm (2.45 inch) | 88mm 4 | 66.5mm (2.62 inch) | 94mm 4 | 67.9mm (2.67 inch) | 96mm 4 | 72.1mm (2.84 inch) | 102mm 4 | 73.5mm (2.90 inch) | 104mm 4 | 84.9mm (3.34 inch) | 120mm 5 | 43.5mm (1.71 inch) | 74mm 5 | 55.2mm (2.18 inch) | 94mm 5 | 64.7mm (2.55 inch) | 110mm 5 | 76.4mm (3.01 inch) | 130mm 5 | 79.4mm (3.12 inch) | 135mm Calculation formula for bolt circle diameter: 4-bolt: Distance between adjacent holes ÷ 0.7071 = bolt circle diameter 5-bolt: Distance between adjacent holes ÷ 0.5878 = bolt circle diameter