Shimano BB-UN300 Bottom Bracket – Square Taper JIS 73x123mm, BSA English Thread, Reliable Steel Bearings For Mountain & Road Bikes
About this item
Okay, if you're building up a classic bike or just need a solid, no-nonsense replacement for your old bottom bracket, this Shimano BB-UN300 is the real deal.
It's got that square taper JIS spindle that works with a ton of cranksets out there.
This specific one is the 73x123mm size with the BSA (English) threads, so make sure that matches your frame's shell.
It's built with steel bearings, so it's not fancy, but it's tough and will last you a good while—perfect for cruisers, hybrids, mountain bikes, or a touring rig.
Shimano backs it with a 2-year warranty, and it's brand new in the box, ready to go.
Just a heads-up, it has the California Prop 65 warning, which is standard for stuff like this.
At 0.72kg, it's lightweight enough.
Grab it if you need that dependable, workhorse component.
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