BB-UN300 Square Taper JIS Bottom Bracket 118Mm Spindle 73Mm Shell Width Shell ID 1.37 Fits JIS Cranksets For Ultra Smooth Pedaling And Solid Power Boost

BB-UN300 Square Taper JIS Bottom Bracket for 118mm Spindle
✔️ 118mm (4.65in) spindle, 73mm (2.87in) shell, 34.8mm (1.37in) ID, JIS

The BB-UN300 is a square-taper bottom bracket built for JIS cranksets. It's a reliable upgrade for road and mountain bikes, delivering smooth rotation and solid power transfer thanks to a hollow spindle and sturdy aluminum shell with corrosion resistance.

✅ Spindle length: 118 mm (4.65 in)
✅ BB shell width: 73 mm (2.87 in)
✅ BB shell I.D.: 34.8 mm (1.37 in)
✅ Compatible with JIS square-taper cranksets
✅ Hollow spindle design reduces weight
✅ Aluminum alloy shell for corrosion resistance

💡 What is a bottom bracket used for with JIS square-taper cranksets?

A handy explanation for riders considering an upgrade to improve pedaling efficiency. - What it does: connects crankset to frame and lets crank rotate smoothly - Handy note: ensure shell width and ID match your frame - Why JIS square-taper: common, secure, and easy to service