Is a new Shimano BB-UN300 as good as the UN50/70?

[Peachy!]

Just pondering my next BB purchase, so anyone out there tried Shimano's UN300?
They're cheaper than used UN50's & 70's & obviously a lot cheaper than NOS!
So if it's not a catalogue correct build, do the compare favourably?

 

[trailstar82]

Don’t do it!!!!

There’s a thread on here somewhere absolutely slating the 300!

Found it

UN300 - less than 300 miles and it's toast

Hi guys, I just wanted to report my latest encounter with a defective bottom bracket. I purchased a Shimano UN300 for my Boardman and installed it just before going back home for the Xmas holidays. I did about 150miles before the holidays and 150miles since I am back. This morning I noticed...

www.retrobike.co.uk

 

[Peachy!]

Cheers @trailstar82 that certainly made for an interesting read. Just “splashed out” an extra £3 on a NOS UN55

 

[marc two tone]

When used to un71/72 its hard to trust anything else.
Ask for a used, but tight n smooth un72.
Or look for stronglight jp 400.
Fsa power pro aint too bad.

If un300 is anything like un 55, they can keep it!

 

[Peachy!]

When used to un71/72 its hard to trust anything else.
Ask for a used, but tight n smooth un72.
Or look for stronglight jp 400.
Fsa power pro aint too bad.

If un300 is anything like un 55, they can keep it!

Yeah I think I’ll be using the 55 as cheap stop gap, and will keep my eye out for a good used 71

 

[MattiThundrrr]

Funny thing about timing... Just went to my parts guy today and the subject of BB's came up.

Deore DX BB still in the box, and at least 5 nos UN55s...
By the way, that STI cassette on the left is no longer nos...

 

[CassidyAce]

@Peachy! You might find this old thread on Cycling UK's forum interesting: https://forum.cyclinguk.org/viewtopic.php?t=141038. It's a pretty detailed discussion. Looking over it again, though, it doesn't look like the question about the UN300 was answered but they were, perhaps, too new at the time.