BB drag - HELP!
 

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[Closed] BB drag - HELP!

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Hi all,
Started assembling my new (to me) bike today.
It's got a second hand (but reasonably new) XT Bottom Bracket.
The first thing I did was remove the plastic seal, clean out the BB and then add a load of grease before replacing the seals.
I then cleaned and greased the BB cup threads and the BB threads in the frame.

After putting the crank arm in, I noticed it doesn't seem to rotate freely at all, even if I push it, it just stops immediately. There is also an ever so slightly gritty feeling in the drive side BB cup - but this is inside the bearings, which I couldn't find a way to remove.
The non drive side BB cup sounds fine, but the bearings are a bit stiffer.

Should I be worried by the resistance against the crank spinning? If so, what is the best plan of attack.

Thanks for any help!


 
Posted : 10/03/2013 12:38 pm
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A bit of resistance is normal - but then I've never attempted to re-grease a Shimano HT BB. Just make sure you've not overdone the BB preload. That seems to cause most BB failures.


 
Posted : 10/03/2013 12:42 pm
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I've just tried spinning the crank with the axle half in, so it only is in contact with the drive side BB cup, it span freely.
I guess this means that the non drive side cup is the one causing the resistance.
Should I bother trying to free up the bearings somehow?
Also, the gritty feeling in the right cup - is this anything to worry about?

Thanks scotroutes, I'll try an remove some of the grease I packed in.


 
Posted : 10/03/2013 12:48 pm
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Bump!


 
Posted : 10/03/2013 2:05 pm
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Rose bikes...New xtr bb...There only cheap 😉
http://www.rosebikes.co.uk/article/shimano-xtr-bottom-bracket-cups-hollowtech-ii-sm-bb90/aid:274227


 
Posted : 10/03/2013 2:07 pm
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Wow that's cheap, still doesn't take away from the fact that I have literally, no money.
Guess I'll have to use it as it is unless some advice comes along.


 
Posted : 10/03/2013 2:11 pm
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Quite normal for a newly repacked bearing to be sticky/slow, could be as simple as that... Also, remember that the amount of drag that's obvious when you spin it by hand probably won't be obvious when you spin it by foot.


 
Posted : 10/03/2013 2:32 pm
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I've promised work to the parents in return for £20 to buy a new BB.
Being my first bike build, and having invested so much time and money in it, I want to get it right first time.
Also, pretty sure the bearings in the non drive side are not right, they are ridiculously stiff and don't seem to rotate unless under a lot of force.


 
Posted : 10/03/2013 4:06 pm

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