Bottom Bracket Play...
 

[Closed] Bottom Bracket Play - Will it damage the frame?

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I've got a fair bit of play in my bottom bracket, would rather leave it a month till I get paid to get a decent one, question is, will it damage my frame if I keep riding it??

Cheers


 
Posted : 22/05/2012 8:11 pm
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NO it wont damage the frame


 
Posted : 22/05/2012 8:12 pm
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what kind of bottom bracket?

If normal screw in type - octalink, external etc then it should be fine as long as it's not severe enough for the chainrings to come into contact with the frame (yes I have seen one come close). But double check it's just the bearings and not the cups or an arm that is loose as loose cups will damage the frame and a loose crank arm will wreck the arm.

If it's a push/press fit BB then no if it's the bearings but if it's the fit in the frame then yes you will most certainly damage the frame if you continue to use it as you will oval the holes.

Long answer but should cover a few options!


 
Posted : 22/05/2012 8:14 pm
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As andyl says. If it is the bearings then no but if it is a loose cup etc then yes.


 
Posted : 22/05/2012 8:15 pm
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Somehow I knew this would be straight forward! As far as I'm aware its a straight forward shimano one SM BB51 like the one linked below!

[url= http://compare.ebay.co.uk/like/140704239738?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar&cbt=y ]link[/url]


 
Posted : 22/05/2012 8:17 pm
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Still no
Cannot see that is loose cups causing play but you could check by removing the cranks and manually feeling for the play - it will be the bearings and not a moving cup in an ovalised frame IMHO


 
Posted : 22/05/2012 8:21 pm
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Somehow I knew this would be straight forward! As far as I'm aware its a straight forward shimano one SM BB51 like the one linked below!

link

Most likely (by a long way) to be the bearings as Junkyard says.

Reason I asked is push fit ones can be prone to coming loose in the frame - in fact seem to see more people having them come loose than fail.


 
Posted : 22/05/2012 10:18 pm
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seen a few loose bbs destroy bb threads in the frame.


 
Posted : 22/05/2012 10:20 pm
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Yup, I've had to sort out more than a few frames where the threads have been knackered by a loose BB.


 
Posted : 22/05/2012 10:23 pm
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nearly had this happen, my fault for not checking cause of creaks quickly enough. threads are reduced but still good enough probably because frame is 7075 and cups were 6061 or something softer.

how do you sort out damaged bb frame threads then?


 
Posted : 22/05/2012 11:07 pm
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On a steel frame, fill the threads with brass and recut them. On an alloy frame, it's possible to bond in a steel insert - though it's often easier to just use a threadless bottom bracket.


 
Posted : 22/05/2012 11:25 pm
 DezB
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Just get a Deore one and replace it. Or put a wanted ad on the forum, someone might have some bearing cups they
will send you for a few quid.


 
Posted : 22/05/2012 11:41 pm
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thanks ben, so are there press fit bbs that'll fit a reamed out old style 68mm shell? or some sort of shim needed?


 
Posted : 23/05/2012 12:11 am
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They're not press-fit (I don't know of any anyway) - they thread to themselves so the LH cup threads onto the cartridge body. Square taper only, for the ones I've used.


 
Posted : 23/05/2012 8:00 am
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right thanks, will try not to let my cups come loose again. other thing is some have longer threads (like Shimano SAINT?) which i should probably be using ... shame Hope don't make longer driver side cups, can't understand why not really.


 
Posted : 23/05/2012 12:12 pm