What will replace the quality of the discontinued Shimano BB-UN55?

[Houthakker]

SpaCycles seem to be using inexpensive FIRST COMPONENTS Bottom Bracket F-2001P in their own builds.

I got one of these from Spa when I bought a new chainset and fitted it at the weekend which, or at least tried to. Only a couple of threads in and the ring that the tool locks into sheared off!

 

[rogerzilla]

Bike manufacturers have been fitting el cheapo BBs since the dawn of time. No-one looks and, even if you did, you would have trouble telling what was in there. Nice rear mechs sell a bike.

 

[GuyBoden]

A UN-300 wasn't available in the right spindle length when I bought a wedge of items from Spa: so I went for Stronglight rather than the cheaper 'unbranded' alternative. The fact that Spa are using the 'First' BB must be a recommendation in itself.
Sorry if my question could seem impolite: was just genuinely interested what you'd found on comparative durability. I did do some net searching but failed to find owt where you succeeded.

A bit of info:
I've read from various sources that the Stronglight JP400 is a rebranded Kinex.

Kinex make very good quality BBs and are popular in mainland Europe.

https://www.singlespeedshop.com/Sin...ries/Kinex-Bottom-Bracket---Square-Taper.html

https://www.spacycles.co.uk/m16b0s110p140/STRONGLIGHT-Bottom-Bracket-JP400-Aluminium

 

[Milkfloat]

Until people start having issues with the UN-300 or I cannot get the right size I won't walk away from Shimano, I have never had a problem with their BBs over the years, so have no need to doubt them now. I actually have quite a few part worn BBs in my parts bin, mainly because I assumed they must be past their prime when diagnosing other issues, only to find out after replacing them that there was nothing wrong with them.

 

[rogerzilla]

I have had two bad UN5x BBs over the years. One was a UN52 or UN53 on a new Thorn Nomad. Started squeaking on a CTC ride near Wantage and was extremely stiff to turn by the time I got home, 20 miles further on. Total life 70 miles.

 

[GuyBoden]

Until people start having issues with the UN-300 or I cannot get the right size I won't walk away from Shimano, I have never had a problem with their BBs over the years, so have no need to doubt them now. I actually have quite a few part worn BBs in my parts bin, mainly because I assumed they must be past their prime when diagnosing other issues, only to find out after replacing them that there was nothing wrong with them.

Luckily, I still have a made in Singapore not Indonesia, 113mm, unused Shimano BB-UN55 in my garage, but I only have one, but 4 bikes.

 

[GuyBoden]

I have had two bad UN5x BBs over the years. One was a UN52 or UN53 on a new Thorn Nomad. Started squeaking on a CTC ride near Wantage and was extremely stiff to turn by the time I got home, 20 miles further on. Total life 70 miles.

I've had the most problems with cup and cone with loose bearings, due to the grease washing out during winter riding, the Shimano BB-UN55 have been a vast improvement.

 

[GuyBoden]

More info, if you need it, on BB-UN55 v BBUN300
https://www.restoration.bike/bikes-and-parts/bb-un55-vs-bb-un300/

 

[Ajax Bay]

Thank you, @GuyBoden
Not sure I think they're right that one is better than the other. The UN-55 is no longer made: the UN-300 is its replacement. The UN-55 is more expensive because it's increasingly rare: their 'pricier is better' conclusion is flawed. Both have steel 'cups' to screw in. Both have 'one piece' bodies. "Bigger bearings"!? Sorry? Groupset alignment is an irrelevance, imo. Tourney has a square taper chainset: so it needs a ST BB.
From the link:
"A big question then remains, between the still readily available and newer BB-UN300, and the older tried-and-true BB-UN55, which of these two is better?
"There are a number of reasons when looking at a BB-UN55 vs BB-UN300 I’d pick the first one.

• The BB-UN55 has always been more expensive than the BB-UN300. And although there is no straight-up comparison on the internet between the two, an increase in price usually means that higher-quality materials are used. The one-piece body of the BB-UN55 and bigger bearings suggests just that.
• The BB-UN300 is offered within the current Shimano Tourney MTB groupset. This is the lowest-tier groupset that Shimano offers, further strengthening the assumption that indeed the BB-UN55 is a higher-quality build.

". . . . there’s really nothing wrong with what I consider to be one of the most failsafe bicycle parts ever to hit the market, square taper bottom brackets would need to go some day. . . . if you are looking for a solid option for your restoration project and you ask yourself which one is better between the BB-UN55 vs BB-UN300, I would always choose the BB-UN55."
Square taper BBs will not "go some day". They will be here forever (check back with me in 10 years). The author might "always choose a UN-55" but only because they have stash of 20 various spindle widths. Mere mortals will have to use what's being sold: UN-300 or another make (see up thread).

 

[GuyBoden]

Thank you, @GuyBoden
Not sure I think they're right that one is better than the other. The UN-55 is no longer made: the UN-300 is its replacement. The UN-55 is more expensive because it's increasingly rare: their 'pricier is better' conclusion is flawed. Both have steel 'cups' to screw in. Both have 'one piece' bodies. "Bigger bearings"!? Sorry? Groupset alignment is an irrelevance, imo. Tourney has a square taper chainset: so it needs a ST BB.
From the link:
"A big question then remains, between the still readily available and newer BB-UN300, and the older tried-and-true BB-UN55, which of these two is better?
"There are a number of reasons when looking at a BB-UN55 vs BB-UN300 I’d pick the first one.

• The BB-UN55 has always been more expensive than the BB-UN300. And although there is no straight-up comparison on the internet between the two, an increase in price usually means that higher-quality materials are used. The one-piece body of the BB-UN55 and bigger bearings suggests just that.
• The BB-UN300 is offered within the current Shimano Tourney MTB groupset. This is the lowest-tier groupset that Shimano offers, further strengthening the assumption that indeed the BB-UN55 is a higher-quality build.

". . . . there’s really nothing wrong with what I consider to be one of the most failsafe bicycle parts ever to hit the market, square taper bottom brackets would need to go some day. . . . if you are looking for a solid option for your restoration project and you ask yourself which one is better between the BB-UN55 vs BB-UN300, I would always choose the BB-UN55."
Square taper BBs will not "go some day". They will be here forever (check back with me in 10 years). The author might "always choose a UN-55" but only because they have stash of 20 various spindle widths. Mere mortals will have to use what's being sold: UN-300 or another make (see up thread).

Yes, the author's conjecture is flawed, but an interesting discussion nevertheless. I've purchased a new Tange Seiki BB and I already have a NOS BB-UN55 as spares. Obviously, over time we will find out if the new BB-UN300 is durable, but due to it's design, I'm initially not convinced and prefer the Tange Seiki LN-7922 or Tange Seiki LN3922 designs.

 

[Milkfloat]

I too have a few 55s floating around, if I don’t have the right size I will buy a 300 and not stress about it. Worse case after 5 or 10 years I will spend 10 minutes and £10 on a new one.

 

[fossyant]

Come on folks, the new UN300 is quite blingy, and the non drive side looks like you can actually regrease the bearing. It also has an additional seal, so should be good enough. Obviously not as good as my UN91 and UN71, but they are like rocking horse poo now. It will do for the bucks.

At least they last longer than SRAM GXP - you can kill them on a wet ride.

 

[Blue Hills]

Come on folks, the new UN300 is quite blingy, and the non drive side looks like you can actually regrease the bearing.

Can you clarify this to a non techie?
If you can regrease the bearing doesn't this mean that it's not properly sealed?
I thought the whole point of a cartridge BB was that everything is closed off from the elements and user.

On the UN55 I do have a few laid up.

Bought two more brandnew ones from ebay folks as soon as I realised it had been continued - won with low bids.
One cost about £4.50, other about £7.50 - neither any postage, picked up.

 

[fossyant]

Can you clarify this to a non techie?
If you can regrease the bearing doesn't this mean that it's not properly sealed?
I thought the whole point of a cartridge BB was that everything is closed off from the elements and user.

On the UN55 I do have a few laid up.

Bought two more brandnew ones from ebay folks as soon as I realised it had been continued - won with low bids.
One cost about £4.50, other about £7.50 - neither any postage, picked up.

It's a slightly different construction to the UN55. The outer non-drive bearing is pressed to the body (rather than inside it), and you can pop the outer seal off the bearing. The non-drive side cup has an additional seal fitted to it, so doubles up on the one on the bearing. The drive side one isn't accessible.

 

[Blue Hills]

It's a slightly different construction to the UN55. The outer non-drive bearing is pressed to the body (rather than inside it), and you can pop the outer seal off the bearing. The non-drive side cup has an additional seal fitted to it, so doubles up on the one on the bearing. The drive side one isn't accessible.

thanks for the info though not convinced that this is an advantage, never having felt any need to grease a UN55 (apart from outer threads periodically of course)