Oh and while chasing may be a good idea, it still does nothing for alignment and is therefore irrelevant to this thread.
Bike Forum
BB facing - is it really necessary
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Posted 2 years ago #
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So in conclusion people who run bike shops say you have to have it faced BB manufacturers dont seem to mention it in the instructions and most people couldnt be ar*ed unless the bikeshop does it for nowt.
Me I have it done because I am picky and I get it done for the price of a pint.
Posted 2 years ago # -
[quote] But there is always movement between the male and female threads though. Or have you actually used it? [quote]
yep!
hundreds of times! If not more! at least in the last 25 years anyway!
Posted 2 years ago # -
Amazing how stubborn people can be when presented w/ the obvious.
Facing was /is a non-issue for those blessed with one-piece sealed BB units everyone used for 15+years; before that, and now again even more with external ("infernal") cups, if you don't have a faced frame, you will find it very unlikely that the bearings will not bind, grate, and wear even faster than they tend to do anyway.
The threads alone don't adequately align the cups, because they're generally too loose, too short in depth, compared to the cup width, and a non-parallel face will apply pressure unevenly as the cup is tightened, until it forces the cup to lay against the face.
One-piece BBs were great, because all the parallel issues were kept perfectly true inside the integrated unit, sealed and made to very tight tolerances. Facing became an underappreciated step, because the face was only aligning with secondary washers or lockrings not directly applying any force to a bearing or race.
External BB cups are inherently sloppy, and some like FSA are notoriously even made to incredibly lousy tolerances; I will gladly sell anyone an Enduro ceramic bearing/cup that spins free alone, but binds when pressfit into their own cup, using their press, before even installing into a frame.
Facing isn't supposed to be an issue with carbon, as mfg techniques bypass the issue; any metal frame should be faced (Ti can be faced w/ standard cutting dies, use lots of cutting oil) or you risk poor bearing alignment and premature wear.Posted 11 months ago # -
hazeii - Member
I've come to the conclusion that facing doesn't really matter; mainly because the external BBs in my faced MTBs last a few wet rides,
I should be trying to figure out why that is tbh. Unless your idea of a wet ride means riding under the sea.
Posted 11 months ago # -
Holy thread resurrection
Posted 11 months ago # -
Oh yeah!
Posted 11 months ago #
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