Cartridge bottom Brackets

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iandusud
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Cartridge bottom Brackets

Post by iandusud »

Now that Shimano UN55 BBs seem to be thin on the ground I'm wondering what the options are, specifically in my case 68mm x 122.5mm. Plenty of cheap options but I doubt their long term reliability, particularly on the back of a tandem! Spa Cycles list Shimano UN300 and Stronglight JP400. What are the panel's thoughts?
Last edited by iandusud on 17 Jun 2021, 9:18pm, edited 1 time in total.
rogerzilla
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Re: Cartridge bottom Brackets

Post by rogerzilla »

The UN300 is mediocre. People have had them fail already and they are very different inside. Shimano trying to kill off ST (the UN5x was the cheap and heavy range already, the UN9x and UN7x being long gone; even the UN54 still had a hollow axle).

Tange-Seiki are ok, in the "two cups, two cartridge bearings and a sleeve" style. I've had no issues with Token, either. Avoid Genetic Karyotype - if you tighten the cups sufficiently to secure them, the carbon sleeve compresses and the bearings bind.
TheBomber
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Re: Cartridge bottom Brackets

Post by TheBomber »

Do all things Shimano still have a 2 year guarantee? If so you could buy a UN300 and take it back every time it fails. Maybe they’d get the message then too.
tooley92
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Re: Cartridge bottom Brackets

Post by tooley92 »

I’m sure I’ve got a new one in the stash.
Remember folks 'A pessimist is just an optimist with experience!'
slowster
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Re: Cartridge bottom Brackets

Post by slowster »

I think the Stronglight JP400 and (some/all) Miche bottom brackets are made by Kinex in Slovakia. I have not seen a picture of one dismantled, but it looks like a superior design to the UN300 and similar designs. Rather than a central sleeve between two cartridge bearings with the usual small balls, the sleeve covers the bearings. It looks therefore like the bearings are not cartridges, but larger ball bearings with a race on the axle. They might therefore be comparable to the UN55/UN26, depending upon the quality of the seals.

On a general note, it seems that the question of what square taper bottom bracket to buy now that the UN55 has been discontinued is going to keep resulting in new threads being started. We've aready had one lengthy thread on this issue - viewtopic.php?f=5&t=141038, and more recently this one - viewtopic.php?f=5&t=146281. It might be worth merging these threads to keep this sort of information on one thread.

Stronglight JP400
Image

Kinex
Image
rotavator
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Re: Cartridge bottom Brackets

Post by rotavator »

Another one to avoid: First Components F-2001P. This was recommended to me by a well known touring bike shop partly because the plastic cups won't corrode. However, the drive side cup split, my bike became unrideable and I had to phone for rescue in the middle of a big ride.
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531colin
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Re: Cartridge bottom Brackets

Post by 531colin »

rogerzilla wrote: 17 Jun 2021, 3:24pm The UN300 is mediocre. People have had them fail already and they are very different inside. Shimano trying to kill off ST (the UN5x was the cheap and heavy range already, the UN9x and UN7x being long gone; even the UN54 still had a hollow axle).

Tange-Seiki are ok, in the "two cups, two cartridge bearings and a sleeve" style. I've had no issues with Token, either. Avoid Genetic Karyotype - if you tighten the cups sufficiently to secure them, the carbon sleeve compresses and the bearings bind.
I'm reasonably optimistic about UN300.
True, its a "2 cups, 2 cartridge bearings, and a sleeve" offering. like so many others.
However, the Shimano cups have a grease seal in each side, and its fairly straightforward to introduce some grease between the cups and the cartridge bearing. viewtopic.php?f=5&t=105385&start=15....this may not extend the life of the bearing greatly, but its unlikely to do any harm.
I doubt that UN300 will last as well as UN5x, but I don't know why they would be measurably inferior to all the other similar units?
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531colin
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Re: Cartridge bottom Brackets

Post by 531colin »

slowster wrote: 17 Jun 2021, 9:17pm I think the Stronglight JP400 and (some/all) Miche bottom brackets are made by Kinex in Slovakia. I have not seen a picture of one dismantled, but it looks like a superior design to the UN300 and similar designs. Rather than a central sleeve between two cartridge bearings with the usual small balls, the sleeve covers the bearings. It looks therefore like the bearings are not cartridges, but larger ball bearings with a race on the axle. They might therefore be comparable to the UN55/UN26, depending upon the quality of the seals.......................
I had a JP400 kicking about in the shed for years.....it looks like I have thrown it away, just when it would be really useful to have one to cut up. Maybe I can scrounge one out of the shop scrap bin!
rjb
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Re: Cartridge bottom Brackets

Post by rjb »

My experience with Kinex bottom brackets has not been favourable. Link here to the internals. Note how few balls there are and how small they have to be. In my experience they have a short lifespan.
search.php?keywords=Kinex&t=141038&sf=msgonly
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840 :D
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SimonCelsa
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Re: Cartridge bottom Brackets

Post by SimonCelsa »

I've had continued good use out of the Neco brand from SJS:

https://www.sjscycles.co.uk/bottom-brac ... sh-thread/

You can't get much cheaper than that!!

Fitted 2 x 122.5mm to a tandem (needed the longer axle for an electric hub conversion). Admittedly only seen a couple of thousand mile usage but problem free so far. Unfortunately it appears that SJS are getting low on stock.
UpWrong
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Re: Cartridge bottom Brackets

Post by UpWrong »

I fitted a JP400 to a recumbent recently. It certainly had the look and feel of a quality BB. It rotated freely both before and after installation, better than the UN55s I have handled recently.
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531colin
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Re: Cartridge bottom Brackets

Post by 531colin »

rjb wrote: 17 Jun 2021, 10:40pm My experience with Kinex bottom brackets has not been favourable. Link here to the internals. Note how few balls there are and how small they have to be. In my experience they have a short lifespan.
search.php?keywords=Kinex&t=141038&sf=msgonly
I'm not clear from your linked piece whether your dis-assembly of the unit was destructive or non-destructive?
If I could dismantle the unit sufficiently to (annually?) add a decent quantity of good grease with corrosion inhibitors and re-assemble it without damage, that might be a good trade-off for reduced bearing numbers/size?
hamster
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Re: Cartridge bottom Brackets

Post by hamster »

I destroyed a Token in two MTB singlespeeding winters. There is a design weakness: the cup is a water trap allowing water past the seal into the bearing. The splines are shallow too. Typically I got 30,000-50,000 miles from a UN-7x.

I've now bought a Genetic Karyotype (around £40) which has the nice hollow axle like the superb UN-7x of old. Weight 220g (103mm). Fingers crossed it's more durable.
rjb
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Re: Cartridge bottom Brackets

Post by rjb »

531colin wrote: 18 Jun 2021, 10:14am
rjb wrote: 17 Jun 2021, 10:40pm My experience with Kinex bottom brackets has not been favourable. Link here to the internals. Note how few balls there are and how small they have to be. In my experience they have a short lifespan.
search.php?keywords=Kinex&t=141038&sf=msgonly
I'm not clear from your linked piece whether your dis-assembly of the unit was destructive or non-destructive?
If I could dismantle the unit sufficiently to (annually?) add a decent quantity of good grease with corrosion inhibitors and re-assemble it without damage, that might be a good trade-off for reduced bearing numbers/size?
I could have reassembled it but the reason I took it apart was idle curiosity. It had developed significant play in the bearings and when dismantled there was significant pitting of the axle races. The seal had probably let water past it although there wasn't much sign of contaminated grease internally. If you can remove the seal without damaging it and get more grease or even semi fluid grease inside it may well prolong its life. Good luck to anyone who attempts this. Let us all know how you get on.
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840 :D
Bonzo Banana
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Re: Cartridge bottom Brackets

Post by Bonzo Banana »

This Tandem seller has Tange as well as as the Shimano UN55. I realise Tange was mentioned earlier in the thread so I guess this would backup that suggestion.

https://www.tandems.co.uk/m8b0s56p0/Com ... m-Brackets

They seem to have stock of the UN55 though.
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