Square taper bottom bracket - new UN300 or old style UN55?

[NHAero]

Shimano square taper BBs have always been bombproof for me. I learned that the UN55 is discontinued and the replacement is UN300. The new one is less expensive, so I wonder if it's also less good. It's not like a UN55 is gonna break the bank if I find one.

Any input on how they compare?

[donevwil]

I had the same dilemma a couple years ago, questioned how good the UN300 could be at the price, but ultimately I just dove in and bought one. To be honest it's a much nicer BB than the UN55 in every tactile and aesthetic way, no plastic cup, everything plated and shiny. The bike hasn't seen many miles so can't really speak to the bearings, but they felt fine out of the box and haven't been an issue.

[Spaghetti Legs]

Yeah the UN-55 is (was) a great BB. The adjustable cup is plastic on the 300. I forget the other differences but when I looked into it a year or so ago I decided not to get one. I usually go with Velo Orange, IRD, or Sugino for my JIS taper cranks.

Edit, I see post above and I guess no plastic cup. Woulda sworn it had one but it’s been a while.

[jamesdak]

^ Yep, I like a trouble free BB's and the last few times splurged on the IRD-95 BB's. A really nice product that isn't a lot of money and spins so nicely.

[KrispyK]

I like the new UN300. Works great. great price. Spins well.

Also cannot go wrong with other options mentioned from IRD or the Tange Seiki LN7922

[tellyho]

I'd go with the Tange(which I have several times since the demise of the high quality Shimano square taper). Although it's likely Tange makes the Shimano one.