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

[Jameshow]

OK, I've installed a Shimano UN300 BB in my bike today, lets see how long it lasts. I've put an excessive amount of grease inside and outside of the BB, which I'll do every year, it's not too tight, so not to overload the bearings.

Shimano UN300 BB on offer for £11
https://www.sprocketscycles.com/products/shimano-bb-un300-bottom-bracket-british-thread?currency=GBP

Give us an update on Monday!

 

[Ajax Bay]

Shimano UN26 68x113 Bottom Bracket £5.49 at Ribble.
(Yes, the type with the rubbish plastic cup, but you can use your old metal BB cup.)
https://www.ribblecycles.co.uk/shimano-bb-un26-square-taper-bottom-bracket-silver-113x68/

OK, I've installed a Shimano UN300 BB in my bike today, lets see how long it lasts. I've put an excessive amount of grease inside and outside of the BB, which I'll do every year, it's not too tight, so not to overload the bearings.
Shimano UN300 BB on offer for £11
https://www.sprocketscycles.com/products/shimano-bb-un300-bottom-bracket-british-thread?currency=GBP

I very much like your idea of using a UN-26 with a previously used metal left hand screw-in end. I believe (on no evidence other than one that lasted at least 25,000km) it's the same bearing set as a UN-55 with the LH plastic end (which disintegrated when I tried to remove it, btw, LBS no prob) the only difference.

 

[GuyBoden]

Give us an update on Monday!

Unbelievably, the Shimano UN300 BB didn't disintegrate during the ride today.

 

[Ajax Bay]

How's the UN-300 going @GuyBoden ? How many thousand kms?

 

[GuyBoden]

How's the UN-300 going @GuyBoden ? How many thousand kms?

I've designed the ultimate maintainable bottom bracket from available parts, it's this:

https://www.cyclechat.net/threads/t...bearing-square-tapered-bottom-bracket.293687/

 

[fossyant]

How's the UN-300 going @GuyBoden ? How many thousand kms?

Over 18 months on mine of commuting all weathers. It's still fine. Picked up a spare cheap from Wiggle a few weeks back.

 

[Ajax Bay]

Looking at my as yet uninstalled UN-300, it seems there's an extra part seal on both bearings.

 

[silva]

Bring this thread up since related.
I have to choose a square taper axle.
Dealer informed me Shimano UN55 production ceased.
And that its successor is inferior.
I'm offered a Stronglight JP400, but since I had cranks of that brand that broke at their pedal eyes, I initially refused.
But I'm not given an alternative, have to find one myself then.
The JP400 is entirely steel but has aluminium cups.
I rather expect steel to be used for a wearing part, but no, can that have a specific reason other than weight reduction?
Alternatives?
The required length is 122.5 mm.

 

[silva]

What about this:
https://www.brico.be/nl/tuin-terras...et-stalen-cups-jis-122-5-31-mm/10262731#specs
(I translated)
Neco Axle
Including two crank bolts
Steel cups at both sides
Weight 343 gram
JIS
Diameter axle: 31 mm
Thread BSA (BC 1.37" x 24T)
Length L1: 122,5 mm
Length L2: 68 mm
Length L3: 28,5 mm

 

[fossyant]

Bring this thread up since related.
I have to choose a square taper axle.
Dealer informed me Shimano UN55 production ceased.
And that its successor is inferior.
I'm offered a Stronglight JP400, but since I had cranks of that brand that broke at their pedal eyes, I initially refused.
But I'm not given an alternative, have to find one myself then.
The JP400 is entirely steel but has aluminium cups.
I rather expect steel to be used for a wearing part, but no, can that have a specific reason other than weight reduction?
Alternatives?
The required length is 122.5 mm.

Just get a UN300 - no problems from mine and they aren't expensive. Far better than GXP etc. Stop faffing.

 

[Ian H]

Bring this thread up since related.
I have to choose a square taper axle.
Dealer informed me Shimano UN55 production ceased.
And that its successor is inferior.
I'm offered a Stronglight JP400, but since I had cranks of that brand that broke at their pedal eyes, I initially refused.
But I'm not given an alternative, have to find one myself then.
The JP400 is entirely steel but has aluminium cups.
I rather expect steel to be used for a wearing part, but no, can that have a specific reason other than weight reduction?
Alternatives?
The required length is 122.5 mm.

The cups are not 'wearing parts'. Their only function is to secure the unit in the frame.

 

[Tom B]

Bring this thread up since related.
I have to choose a square taper axle.
Dealer informed me Shimano UN55 production ceased.
And that its successor is inferior.

In what way does the dealer feel it is inferior?

Just get a UN300 - no problems from mine and they aren't expensive. Far better than GXP etc. Stop faffing.

Agreed. My everyday bike has had one in for about 3 years, easily 8-10k miles in all weathers with no love. no issues to date. The bike has about 31'000 Strava miles and has had at least 2x UN55s and one very short lived Sunrace BB. The UN 300 is probably now reaching the same miles as the UN55s

 

[Drago]

In what way does the dealer feel it is inferior?

It probably earns them less profit.

 

[fossyant]

The UN55 came with an alloy locking cup, which was better than the plastic crap. I had a few spare. The UN55 was the 'best' available Square taper.

My commuter would eat through BB's - as in smooth but wore out - that might be as a result of in-perfect threads, even for cartridge BB's.

The replacement UN300 hasn't been touched in 2 years or so now, is still smooth and the chain ring spins and spins. I didn't get 2 years out of the UN55.

I do have a UN71 and a UN91 (unobtanium) in the fleet of bikes, that have only been removed to ensure the threads are fine, since fitted, about 20 plus years ago.

UN300 is fine.

 

[DCLane]

We've a couple of Velo Orange square taper BB's. They're lovely but pricey - https://freshtripe.co.uk/velo-orange-grand-cru-english-threaded-bottom-bracket/