What's the life expectancy of a bottom bracket

[joebe]

I've been running a Shimano 105 (5600 I think) bottom bracket for a bit over 2 years now (13000 miles). In the last couple of days a lot of play has appeared in the crank which seems to be down to the disintegration of a plastic sleeve on the the non-chainring side. Now I'm thinking it's probably time to replace the whole unit rather than messing around looking for spares, especially as the cost is only about £20.

If I do replace it is it simply a case of unscrewing the cups and bobs your uncle, or are there any hidden pitfalls?

 

[fossyant]

I re-use my alloy sleves as the plastic ones are crap, and I've had a BB stuck because of a plastic sleve fail....

It's likely to be cartridge - so quick replacement - upgrade to one with an alloy locking sleve !!!

 

[jimboalee]

+ 1 on fossyant.

In the early days of Cartridge brackets, I was told "Fit and Forget", but not so with the plastic sleeve.

 

[mr Mag00]

+1

 

[jay clock]

Fitting is generally ok, but take it easy. The thread usually means that you undo anticlockwise on the left hand side and clockwise on the right. ie turn the spanner forwards on each side.

If they will not undo easily put the tool in a vice or workmate and place the bike onto the tool - start on left hand side. The hold the main diamond of the frame (not front or rear forks) and (checking you are turning the correct way) use the frame to turn against the tool. Best to have the tool facing upwards, and use modest body weight to seat the tool as you push down.

Then clean up really well, grease threads and fit new one. Careful not to bugger up the threads when putting new one in like I did!

 

[Steve Austin]

shimano 5600 bb

what plastic sleeve?

13000 is a lot of miles even if it is a cartridge BB that i think you got. I reckon 6 months on a well used bike is the most anyone can expect

 

[Tynan]

6 m,onths?

really?

 

[Steve Austin]

Yes i do. On a well used bike i think 6 months is about right. Its a disposable product like cables, tyres etc.
I think we expect them to last longer but in reality they don't. 2k off road and 5/6k road miles would be plenty long enough life expectancy ime.

I don't expect this to be a popular opinion, but its mine.

 

[yello]

5/6k road miles would be plenty long enough life expectancy ime.

Blimey! I guess it depends on the make/quality of the bb, riding conditions, etc etc etc but that still seems a short life span to me, though I do agree that you treat them as consumables.

 

[jimboalee]

This was done on an old (scrapper) Raleigh Randonneur 27 x 1 1/4" tourer I bought off my LBS owner friend. I stripped it and rebuilt it, installing a Shimano cartridge bracket - £18.

From 1st Jan 2000 to 31st Dec 2000, the bike needed 7 punture patches in the rear tube and five in the front.

When this was over, I removed the Shimano bracket and put it in another bike because there was nothing wrong with it.

 

[spandex]

6 months OMG I know that they are a disposable product but 6 months I am very hard on my bikes even when I was riding for a living I think I have killed 2 I think since I was 14.

But saying that I have had someone come into the LBS I was working in changed there BB and 3months later they are back for a new one as there is loads of play? maybe it is just down to how you ride.

 

[jimboalee]

In the bad old days of 'loose bearing' brackets, my friends and I had 'tracker bikes' for off road and jumping - crazy stuff.
Grasping the RH crank and giving it a sideways tug was a weekly affair, and more often than not, the adjustable cup needed tweaking.

Three of my bikes have loose bearing brackets, and old habits never die. I installed a new set of cups and loose bearings on my winter commuter, and the bracket's first adjustment ( bedding in ) was after 1 week. I think I'll check it today.

Cartridge brackets are IMHO, fantastic. If they show signs of loosness and it cannot be cured by tightening the LH sleeve within 6 months, you can feel hard done by.

If cartridge brackets didn't exist, LBS owners would be even more wealthy.

 

[Mr Pig]

Six Months! Gosh, that's a bit pessimistic isn't it I've never had one fail that quickly.

 

[john59]

I've covered 16000 miles plus on one of my bikes and the original Shimano cartridge bottom bracket is still going strong.

 

[RedBike]

Six Months! Gosh, that's a bit pessimistic isn't it I've never had one fail that quickly.

I went through 3 xt bottom brackets in 9 months. There was never any play in them, quite the opposite in fact. I would get dirt/water in the bearing cups and they'd eventually rust solid.

I've now switched to a Hope ceramic bottom bracket in the hope that it might just last a little longer. So far so good!

I've never had any problems with the bottom bracket on my road bike; but then again I don't go riding it through deep puddles / muddy swamps!