Remove Bottom Bracket

Sorting out your thrunge brackets, fettling your inter-rositers and even stuff about bike parts.
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aidso
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Remove Bottom Bracket

Postby aidso » Wed Oct 03, 2012 18:54 pm

I am attempting to service my BB myself and have gotten as far as taking the pedal off.....woop - t - do haha. Anyway, I am presented with the picture here: http://i.imgur.com/ARexE.jpg
In all of the videos I have looked at, it says to turn the chain-side pedal and tap the bit that's poking out and then the cranks will come off the other side.
But if you look closely at the image, the poking-out-bit is part of that inner disc and therefore the rod won't budge.

Do I have to unscrew something else first?

The reason for me trying to service it - I am hoping to find some ball bearings that need replaced behind this thing - is because there is movement in this poking-out-bit.

Oh the crankset is a Shimano Fc-M552 from a Cube Ltd Race 2012.
Any ideas?

Chunkers1980
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Re: Remove Bottom Bracket

Postby Chunkers1980 » Wed Oct 03, 2012 19:01 pm

No, just tap it with something softer. You can't service those bearing, you need a new one

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aidso
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Re: Remove Bottom Bracket

Postby aidso » Wed Oct 03, 2012 19:08 pm

Ive been tapping it with a hammer but it looks like its joined to that disc thing.

New cups I am guessing??...once i get the feckin thing off

Chunkers1980
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Re: Remove Bottom Bracket

Postby Chunkers1980 » Wed Oct 03, 2012 19:10 pm

Don't use a hammer, give it a good whack with some wood or mallet.

And yes, new cups.

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cooldad
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Re: Remove Bottom Bracket

Postby cooldad » Wed Oct 03, 2012 19:51 pm

That disc thing is the bearing seal. Just hold a piece of wood against the end of the spindle and give it a bloody good whack with the hammer.
Assume you have a BB tool and preload tool?
Not sure what vids you've been watching to expect a load of ball bearings, but read Parktools (Read this first in my sig) first.
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aidso
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Re: Remove Bottom Bracket

Postby aidso » Wed Oct 03, 2012 20:01 pm

I have a BB Install tool which allowed me to loosen that grey cup thing, don't have a pre-load tool.

Someone told me that the rocking was because of worn bearings and I had it in my head that it would be like the little ball bearings you see in your headset. So the optimist in me had planned to strip the bottom bracket, clean and grease the ball bearings and put it back together - and the rocking will have gone.
Looks like this is is not going to be the case :(.

Chunkers1980
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Re: Remove Bottom Bracket

Postby Chunkers1980 » Wed Oct 03, 2012 20:04 pm

I think you bought the wrong tool. You should have checked the preload first, there might have been nothing wrong with the bb, just loose.

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aidso
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Re: Remove Bottom Bracket

Postby aidso » Wed Oct 03, 2012 20:11 pm

Can you help a brutha out - what does a pre-load tool do? Im on this Park website and the search is bringing back results for adjusting pre-load on suspension.

Chunkers1980
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Re: Remove Bottom Bracket

Postby Chunkers1980 » Wed Oct 03, 2012 20:15 pm

Just like a headset. The cups need to be pulled together to a certain tension or load so the bearings don't have any movement but are free to roll.

You should have removed the cap when you removed the no drive side arm, before you took your photo.

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aidso
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Re: Remove Bottom Bracket

Postby aidso » Wed Oct 03, 2012 20:19 pm

With the pedal off, I am able to rock that rod up and down although its more noticeable when the crank arm is on.
So the cups were as tight as can be and the rod still wiggled.

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aidso
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Re: Remove Bottom Bracket

Postby aidso » Wed Oct 03, 2012 20:23 pm

This is another pic where I have managed to unscrew the grey cup thing, but it just spins and doesn't come off the end:
http://i.imgur.com/BJ3Rm.jpg

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cooldad
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Re: Remove Bottom Bracket

Postby cooldad » Wed Oct 03, 2012 20:29 pm

It is out, being held on by the axle. Put it back and knock the crank out. The 'tightness' of the cups will make no difference.
Read Parktools. Click on the pic around the BB area and the info will come up. Or click on the BB link on the right of the page.
Read, then fiddle.
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nicklouse
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Re: Remove Bottom Bracket

Postby nicklouse » Wed Oct 03, 2012 20:46 pm

"Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
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Balaclavas
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Re: Remove Bottom Bracket

Postby Balaclavas » Wed Oct 03, 2012 20:55 pm

http://bike.shimano.com.sg/publish/cont ... lation.pdf

This exploded diagram may help, the part labled "5" is the preload cap. It is this which tightens the bearings, the cups just nead to be tight up against the frame. Try putting everything back together as in the link above in the order shown. The tighten up the preload cap.

This should only be finger tight using the correct tool in order to stop any movement in the bearings. If it has to be more than finger tight, then you may well need new cups. I would recomend using the right tool as it is very cheap.

To remove the crankset from the cups you may have to hit it very hard with a rubber mallet. Trying to remove the cups first will not make this easier. They are the last part to remove.

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aidso
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Re: Remove Bottom Bracket

Postby aidso » Wed Oct 03, 2012 21:02 pm

Thanks, that diagram helps.
It was this I bought and it has that pre-load cap tool on the end of it http://www.ebay.co.uk/itm/150460569721?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2648
I have the thing all back together, the cap on and the pinch-bolts in again and the rocking is still there.

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cooldad
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Re: Remove Bottom Bracket

Postby cooldad » Wed Oct 03, 2012 21:20 pm

So the BB is fubared - new one needed.
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Chunkers1980
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Re: Remove Bottom Bracket

Postby Chunkers1980 » Wed Oct 03, 2012 21:23 pm

Assuming it is preloaded correctly.

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aidso
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Re: Remove Bottom Bracket

Postby aidso » Wed Oct 03, 2012 21:38 pm

Chunkers1980 wrote:Assuming it is preloaded correctly.


Well if I have the left arm off and the rod still has play in it, does that not imply its not the pre-loading?

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cooldad
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Re: Remove Bottom Bracket

Postby cooldad » Wed Oct 03, 2012 21:59 pm

Then it's not preloaded at all. But the axle should be a firm fit without any real movement, whether or not the left arm is on, so I would still say it's time for a new BB.
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The Rookie
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Re: Remove Bottom Bracket

Postby The Rookie » Thu Oct 04, 2012 06:05 am

Frankly your not doing anything anyone says here.....

Put it back together, preload it, does it still have play or not?

It does sound like the bearings have gone, but then your hamfisted efforts maye have done that!


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