Going through BB's

father_jack

I'm going through bottom brackets like nobodies business. I have bought two, possibly three Centuar BB's, and they last about a year, maybe max 1.5 years. I ride to work everyday, about 6 miles.

Is this normal?

I'm pretty sure the Veloce BB lasted longer as I bought the bike used and after buying it, it was a while before I had to replace it. I'll be on the third BB now, and the last one was only fitted recently. Centuar BB isn't cheap at £35 either.

diamonddog

Father Jack wrote:

I'm going through bottom brackets like nobodies business. I have bought two, possibly three Centuar BB's, and they last about a year, maybe max 1.5 years. I ride to work everyday, about 6 miles.

Is this normal?

I'm pretty sure the Veloce BB lasted longer as I bought the bike used and after buying it, it was a while before I had to replace it. I'll be on the third BB now, and the last one was only fitted recently. Centuar BB isn't cheap at £35 either.

Doesn't sound normal to me.

jermas

Are you spraying the bottom bracket area with muc off, degreaser, or wd40? Any of these can strip the grease from the bearings. Over zealous use of a hose pipe whilst washing the bike can also force water into the bearings.

father_jack

jermas wrote:

Are you spraying the bottom bracket area with muc off, degreaser, or wd40? Any of these can strip the grease from the bearings. Over zealous use of a hose pipe whilst washing the bike can also force water into the bearings.

No.

Just found invoice with the BB, it was this time last year, and it was sitting on the shelf for a while. So less than a year? :?

I may pickup a Veloce and see if that lasts longer than the Centuar. Looks like Veloce is discontinued.

is it possible to replace the bearings? £35 every time is too much..

markos1963

Any possibility that the axle/crank angle might have been compromised? i.e. crank dropped whilst out of frame or taken a knock during a spill? Just thinking there might be some sort of lateral pressure being put on the bearing to make it fail.

woolwich

After installation, before you bolt the cranks on, are you checking that the bearing is completely free and not dragging?
I seem to recall that Campag recommend you tighten one end to quite a high setting, maybe 70nm. Then tighten the other end to the same. Then you must check for free movement of the spindle. If there is friction I think they state to back off the torque on one end considerably and use thread lock. This was necessary the last time I installed one, it was replacing a bearing 10 years old so they should be reasonably durable unless you have some sort of frame alignment issue.

father_jack

Chainset turns freely when fitted.

Pross

What is going wrong with it? Is there play or are you just getting noise?

father_jack

There is play in the chainset. Doubt it's the chainset that's loose as both crank arms are wobbling.

Is it possible to replace the two main bearings? Probably £2 each, compared to £35 for a whole new BB.

Ben6899

Father Jack wrote:

There is play in the chainset. Doubt it's the chainset that's loose as both crank arms are wobbling.

Is it possible to replace the two main bearings? Probably £2 each, compared to £35 for a whole new BB.

Yes.

father_jack

Sure? It's square taper bottom bracket, not the ones with external bearings.

http://www.kinokocycles.com/media/catal ... 020536.jpg

MichaelW

Most people are talking about Ultratorque (UT) , not Square Taper (ST).
ST cartridge life is not dependent of facing of the bottom bracket shell (UT is more sensitive to this).
ST cartridges are sealed and cannot be opened or serviced.
ST are a lot more durable than UT and should last for quite a few years of all-weather 2x6 mile commutes.
My Mirage ST style unit lasted for years inc some heavy duty off-road touring and is still good.
If the spindle is wobbling within the cartridge then something serious has gone wrong.

Do the cranks fit firmly onto the spindle. You can damage the ST interface of the cranks by riding lose and once damaged, they often wont fit tight again.

rolf_f

Father Jack wrote:

I may pickup a Veloce and see if that lasts longer than the Centuar. Looks like Veloce is discontinued..

For gods sake stop mis-spelling Centaur. It hurts my eyes almost as badly as break calipers!

father_jack

Cranks fitting onto axle ok.