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[Closed] 'Saving' dead bearings....

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 DrP
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So for some reason both the non driveside bearings on my FS and SS bottom brackets have given out within a week of each other! Completely seized up!

I took the shimano one (FS) out last week and was getting round to ordering a new set, and today noted the FSA (SS) one was pretty stiff too, so again got that one out.
Thought about it for a bit, and seeing as I was about to order some new sets thought I'd stick 'em in the vice, grip the inner ring with some pliers, and try to get them spinning again....

Was pretty rough at first, but broke the 'seal' so to speak. Then got to work with alternating degreaser and GT85 until the muck running out ran clear....
Then packed them full of grease and span them up over and over until it was smooth, cleaned them out and did it again.....

Now I'm not a mechanical engineer, but I am a 'pro garage fettler', and I reckon I've saved these bearings from the scrap heap!! They don't feel rough at all, and are spinning beautifully!

Does the STW collective have any wise words to say on the matter - do you think I'm destined to explode in a ball bearing shower, or will they hold and be good as new...? Bearing (s****) in mind the FSA ones were 2 rides old and seized up a treat, I don't think I've done too baldy, eh?

DrP


 
Posted : 14/12/2009 8:32 pm
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I repaired the big end bearings on a CZ175 the same way and they ran for a couple of years - until I sold it, at least, possibly longer.


 
Posted : 14/12/2009 8:35 pm
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Did you let the greaser dryout before you added the grease ?

(Only asking as I got a right talking to for using petrol as a degreaser once from a 'professional')


 
Posted : 14/12/2009 8:42 pm
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Just done the same to the wife's XT HTII bottom bracket. It was about 3 years old, I reckon I'll get another year at least out of it.


 
Posted : 14/12/2009 8:43 pm
 DrP
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Probably not......

It was finish line degreaser, and I gave it a washout with GT85 and then several packings full of grease....

Then I kissed them goodnight and pressed them back in with a vice and a headset spacer - perfect size!

DrP


 
Posted : 14/12/2009 8:44 pm
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You did right with the Shimano ones. Always worth a try, you aren't going to make any worse.
If the FSA ones were only two rides old you may have just voided the warrenty...


 
Posted : 14/12/2009 8:47 pm
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Are you running HT2 cranks or similar? Non drive side bearings wearing out before driveside is a sign that you're over tightening the preload cap on the crank and putting too much pressure on the bearings. I couldnt work out why the non drive side would go first until I talked to a friendly shimano mechanic at a race this summer.


 
Posted : 14/12/2009 8:48 pm
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did you manage to get the bearings out of the cups then ??
I get 5 ltr's of coma hyper clean. Degrease first then washes off with water, then a blow dry from my compressor, then fresh grease. A little TLC goes along way kids.

what Kitz says above, that cap needs so little torque its unreal, I adjust mine with the 2 allen bolts loose, adjust so there is a tiny bit of play in the non drive crank arm, nip up the allen bolts and then the play has gone..
This has to be why they has failed so quick.


 
Posted : 14/12/2009 8:51 pm
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The reason the non drive side bearings seem to go first is, the exposed gap between the crank arm and the bearing cup alowing all the crap thrown up by the front wheel to get in there. The drive side has the sprockets and spider to deflect a lot of the crap away from that area.

Bearing preload should be equal, as the crank spindle is pulled through by the preload nut, applying the same load on both bearings...Simples


 
Posted : 14/12/2009 9:05 pm
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I flush my bearings in an oil bath with a battery drill while holding the outer casing, uber smoothe!


 
Posted : 14/12/2009 9:42 pm
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Plus 1 for too tight .

I saw this Hope video on BBs and the techie just slightly tightened them - and then loosened them off a 1/8 of a turn.

http://www.hopegb.com/page_mep_force_58.html

Interesting bit at 08:30 if you're impatient.


 
Posted : 14/12/2009 10:41 pm
 jond
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Errr...GT85/WD40 *is* effectively a degreaser - it leaves a little residue but spraying bearings with it is a good way of removing the grease in 'em too (as I discovered after one winter, ruining a loose ball headset). Might be worth looking at them after a few rides to check the grease hasn't gone a bit runny.


 
Posted : 15/12/2009 12:13 am
 DrP
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I know about the GT85 not being too good for grease, but was using it as a penetrator/water remover....

But cheers, will review the grease in a bit.

DrP


 
Posted : 15/12/2009 7:10 am
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Another good way of saving BBs is when the non drive side does enventually give up, save the other side, and if you've got 2 bikes or when the replacement wears out, you'll soon have another non-drive side knackered bearing, just swap the good bearing you saved into that cup.
It does work. 🙂


 
Posted : 15/12/2009 7:24 am
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also if you get the bearings out of the cups, go to a local bearing supplier and get some quality replacements, ie. SKF
guess a tenner for the pair, but don't quote me on that.


 
Posted : 15/12/2009 9:43 am
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and also I wouldn't use GT85 or anything like on bearings as it will degrade the grease.
if you do, make sure you get them nice and clean then re-grease them.

degreaser is the best way though, chuck em in a tub and leave to soak, light scrubbing if possible then just rinse off with water, then dry and re-grease.
and its cheap stuff from any auto parts shop.

http://www.autoexpress.co.uk/products/products/68197/gunk_engine_degreasant.html


 
Posted : 15/12/2009 9:50 am
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If you was to do that before they get seized next time chances are you can make those bearings last indefinately, the seizing bit wont have helped them, but if they are smoothe now then you have cracked it, give them some love every now and then and they will outlast the rest of the bike.. ps new bearings are a fiver, now you know how to get them out and back in again.


 
Posted : 15/12/2009 9:53 am
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I havn't tried to get mine out of the cups because they are good, but is it easy, a pin punch job ??


 
Posted : 15/12/2009 9:58 am
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give it a google rubberscrubber quite a few how too's online..


 
Posted : 15/12/2009 10:02 am
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found this one, quite good but you need a bearing puller


 
Posted : 15/12/2009 10:55 am
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http://www.mountainbikerides.co.uk/fettling/hollowtech2bb.htm

or the DIY guide 😆


 
Posted : 15/12/2009 11:04 am
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sorry no time earlier, this one is quite comprehensive, obviously opinions vary on wether to do it in the frame or in a vice or whatever but the principles are here.

http://www.mountainbikerides.co.uk/fettling/hollowtech2bb.htm

ha ha, i hadnt seen you had posted that one... so good its worth seeing twice!!


 
Posted : 15/12/2009 11:08 am

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