Cartridge bottom Brackets

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alexnharvey
Posts: 1923
Joined: 10 Jan 2014, 8:39am

Re: Cartridge bottom Brackets

Post by alexnharvey »

hamster wrote: 18 Jun 2021, 12:48pm
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.
Whichever moron at genetic thinks it's funny to name their products after terms from genetic science needs sacked, given a sound beating, then sent for a better education in marketing.
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531colin
Posts: 16083
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

STRONGLIGHT JP 400 CUT-UP.

Post by 531colin »

While looking for some garden twine, I chanced upon the Stronglight JP 400 that I thought I should have knocking about. By the time I found the twine it was raining, so a chance to cut up the JP 400!
It seems to be the same thing as "RJB" found with the Kinex .....photos.....larger photos to play with on flickr.

ImageIMG_5443 by 531colin, on Flickr

Thats the whole thing, cut up. Quite a lot of (rather dried out) grease in there. The half shell on the left of my photo shows where I tried a Brucey trick....grinding the case until it was thin, and punching through to make a grease port. I don't think I actually added any grease, it was more of a play to see if I could do it.....the BB was already rumbly and discarded.

ImageIMG_5453 by 531colin, on Flickr

Cleaned up a bit, you can see 7 balls in a retainer, where the balls run on the axle the right side in my photo shows wear through the case hardening. The ball tracks in the case look fine to me, you can see a fine groove which locates the grease seal, and you can see that there is no corrosion inside the BB unit..ie the grease seal seems to have kept the Yorkshire winter out.

ImageIMG_5456 by 531colin, on Flickr

Close up of the wear on the axle....there was a similar but less obvious patch of wear on the other ball track 180 degrees opposite this wear.

ImageIMG_5461 by 531colin, on Flickr

Ball track in the shell; also groove for grease seal.

ImageIMG_5449 by 531colin, on Flickr

Grease seal; the outer (thick) bit has metal in the structure to give it rigidity; the thin bit is flexible to seal.

As there was grease in there, and no corrosion, and it still wore out, I agree with "rjb".....it would be a better job with more balls, and bigger balls.
(a bit like politicians, but there is little hope of either in the real world :wink:)

EDIT; ballbearings are 3/16"
Last edited by 531colin on 20 Jun 2021, 12:41pm, edited 1 time in total.
rogerzilla
Posts: 2887
Joined: 9 Jun 2008, 8:06pm

Re: Cartridge bottom Brackets

Post by rogerzilla »

Seven balls? A good cup and cone BB has 11!

(Apologies for NOS Dura-Ace pr0n)
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kylecycler
Posts: 1378
Joined: 12 Aug 2013, 4:09pm
Location: Kyle, Ayrshire

Re: STRONGLIGHT JP 400 CUT-UP.

Post by kylecycler »

531colin wrote: 18 Jun 2021, 6:11pm While looking for some garden twine, I chanced upon the Stronglight JP 400 that I thought I should have knocking about.
You win the forum today, Colin! :lol: Seriously, I can't talk - that's like the story of my life (and probably a few others on here)!
iandusud
Posts: 1577
Joined: 26 Mar 2018, 1:35pm

Re: Cartridge bottom Brackets

Post by iandusud »

rogerzilla wrote: 18 Jun 2021, 8:57pm Seven balls? A good cup and cone BB has 11!

(Apologies for NOS Dura-Ace pr0n)
I wish that we could still get a range of good quality serviceable BBs like this at a reasonable price. I have two bikes in our fleet that are used almost daily and are over 30 years old. They are fitted with their original Shimano 600 BBs and run as smoothly as ever. They probably get new grease and maybe balls every couple of years.

Ian
cycle tramp
Posts: 3532
Joined: 5 Aug 2009, 7:22pm

Re: Cartridge bottom Brackets

Post by cycle tramp »

It appears that the same issue has been noticed and discussed here, with a suggested alternative

http://thorncyclesforum.co.uk/index.php ... 3#msg84943
Motorhead: god was never on your sidehttps://www.google.com/search?ie=UTF-8&client=m ... +your+side
rogerzilla
Posts: 2887
Joined: 9 Jun 2008, 8:06pm

Re: Cartridge bottom Brackets

Post by rogerzilla »

iandusud wrote: 19 Jun 2021, 7:56am
rogerzilla wrote: 18 Jun 2021, 8:57pm Seven balls? A good cup and cone BB has 11!

(Apologies for NOS Dura-Ace pr0n)
I wish that we could still get a range of good quality serviceable BBs like this at a reasonable price. I have two bikes in our fleet that are used almost daily and are over 30 years old. They are fitted with their original Shimano 600 BBs and run as smoothly as ever. They probably get new grease and maybe balls every couple of years.

Ian
To be fair to cartridge BBs, cup and cone BBs can have a very short life if used in the wet. Even if the cups have good seals, water will often get in via the seat tube. I only use them on dry weather bikes.
iandusud
Posts: 1577
Joined: 26 Mar 2018, 1:35pm

Re: Cartridge bottom Brackets

Post by iandusud »

rogerzilla wrote: 19 Jun 2021, 9:37am
iandusud wrote: 19 Jun 2021, 7:56am
rogerzilla wrote: 18 Jun 2021, 8:57pm Seven balls? A good cup and cone BB has 11!

(Apologies for NOS Dura-Ace pr0n)
I wish that we could still get a range of good quality serviceable BBs like this at a reasonable price. I have two bikes in our fleet that are used almost daily and are over 30 years old. They are fitted with their original Shimano 600 BBs and run as smoothly as ever. They probably get new grease and maybe balls every couple of years.

Ian
To be fair to cartridge BBs, cup and cone BBs can have a very short life if used in the wet. Even if the cups have good seals, water will often get in via the seat tube. I only use them on dry weather bikes.
I take your point but our bikes are used all year round in all weathers. The BB shells are however not open to the seat tube so no chance of water ingress there. They do use a rubber seal between the cup and the axle which seems to do a good job (obviously no pressure washer used).
tooley92
Posts: 1440
Joined: 22 Jun 2007, 9:49am
Location: West Yorkshire

Re: Cartridge bottom Brackets

Post by tooley92 »

Any use?

Ignore the incorrect box, fitted but zero miles BB-UN55 122.5mm 68mm shell.

£25 posted.
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Remember folks 'A pessimist is just an optimist with experience!'
iandusud
Posts: 1577
Joined: 26 Mar 2018, 1:35pm

Re: Cartridge bottom Brackets

Post by iandusud »

tooley92 wrote: 21 Jun 2021, 7:59pm Any use?

Ignore the incorrect box, fitted but zero miles BB-UN55 122.5mm 68mm shell.

£25 posted.
Yes please. PM sent. Ian
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