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Discussion Starter #1
I'm in the process of upgrading the crankset on my 2010 Hardrock. Question is, does the frame need to faced for the use of an external BB? Or are the specialized hardrocks faced from factory? My LBS were I purchased the bike is about a 45min drive. If this step is not needed it will definitely save me some time. Not sure if it matters, but the new crank set is a Race Face Evolve. Thanks
 

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The Quality Control on most production bikes are very high today. About 20 years ago, it was a certainty that framesets and production bikes would require some frame prep, like facing.

It is unlikely your Hardrock will need facing, but you cannot shortcut this process. If your BB does not fit correctly, you need to have the shell prepped, and the only way to know is to install on the new BB.

If the cups are extremely difficult to screw on, not fit tightly against the BB shell, or there is excessive creaking, then the threads need to be tapped and the shell faced.
 

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Thanks for the replies. I 'm going to go ahead and try it without facing. Crankset scheduled to be delivered on Thursday. I oredered the tools, including the exctractor from pricepoint.com and already have them in hand. Thanks again.
 

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Don't monkey around with something like this. Just get the BB faced and do it correctly the first time. It will save you time and maybe money. If the BB shell faces aren't parallel, then the spindle will be off center and will bind up the BB when everything is tightened down.

A sanding block is only as straight as the hand holding it.
 

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frdfandc said:
Don't monkey around with something like this. Just get the BB faced and do it correctly the first time. It will save you time and maybe money. If the BB shell faces aren't parallel, then the spindle will be off center and will bind up the BB when everything is tightened down.

A sanding block is only as straight as the hand holding it.




This , do it once .
 

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I usually do my own work, I even have a facing tool, but one time I left one of my bikes at a LBS to have them install a set of Deore LX cranks/bb while I ran some errands. They just slapped it together without facing the bb shell and when I got it home, I found that the drive side bearing cup was cracked from being cranked down on the uneven bb shell. Thing is, they charged me as if they had faced it too. I say do it right the first time.
 

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Do it right the first time and have it faced. Once it's done, you won't need to do it again.

They're don't care about it in QC if the frame is getting a cartridge BB, like the OP has. There's also the issue of paint on the shell.

Though a sanding block might make the surface flat, it will NOT make the surface perpendicular to the threads, nor will it make the two surfaces parallel to each other.
 

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I have 4 bikes I've built. They're going on 6+ years. I never knew about facing the BB shell and there's a lay of paint on it. Maybe I got lucky.
 

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Discussion Starter #12
Thanks for the replies. I've decided to take it in an have it faced. For $30 might as well do it right the first time.
 

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Wouldn't a cartridge BB be affected the same way? Or is it that the outboard BB registers off of the face of the shell whereas the cartridge does not?
 

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trboxman said:
Wouldn't a cartridge BB be affected the same way? Or is it that the outboard BB registers off of the face of the shell whereas the cartridge does not?


The cartridge seats in an allready machined surface . You are correct that the outboard cups registers on the end of the BB shell which may or may not be flat and both sides parallel .
 

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I guess I'm kinda shocked that they don't make sure that the surfaces of the BB are parallel during mfg. I know it doesn't have to be to be threaded but it sure would be easier to thread if it were...
 

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Modern manufacturing technology is such that it should rarely be needed. Besides, I would trust myself with a sanding block to remove the paint more than I would trust a kid at the bike shop with a facing machine.

If you're worried about the faces not being parrelel, C-clamp a couple of straight edges to faces and measure it. Compare the angles to the seat post and chain stays. Jeez, this ain't rocket science.

If you don't have the skills to do such work, take it in.
 

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rlouder said:
Modern manufacturing technology is such that it should rarely be needed.
You're kidding yourself if you believe that. Most frames can still use facing.

rlouder said:
If you're worried about the faces not being parrelel, C-clamp a couple of straight edges to faces and measure it. Compare the angles to the seat post and chain stays.
That doesn't work either. Trying to do it by hand and still get both faces parallel without taking too much off the shell isn't going to happen.

rlouder said:
Jeez, this ain't rocket science.
It's not, but it's harder than you seem to think it is.
 

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bad mechanic said:
You're kidding yourself if you believe that. Most frames can still use facing....
Mine works great. I must be lucky by beating such great odds. Else, the Forge frame is leaps and bounds better than others.
 

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rlouder said:
Mine works great. I must be lucky by beating such great odds. Else, the Forge frame is leaps and bounds better than others.
Have you put a facing tool on it?

Even if the shell was lathe cut, and even if it was properly masked during painting, you're still going to see some distortion from welding heat. Then to check it, even if you have two precision edges to use (wood is nowhere near precise enough), and even if you could use the frame as a reference (which you can't since all frames are a little of), you still couldn't be sure the edges are perpendicular to the threads and not just parallel to each other. Pretty much the best and easiest way to check the shells faces are by putting a facing tool on it.
 

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bad mechanic said:
Have you put a facing tool on it?

Even if the shell was lathe cut, and even if it was properly masked during painting, you're still going to see some distortion from welding heat. Then to check it, even if you have two precision edges to use (wood is nowhere near precise enough), and even if you could use the frame as a reference (which you can't since all frames are a little of), you still couldn't be sure the edges are perpendicular to the threads and not just parallel to each other. Pretty much the best and easiest way to check the shells faces are by putting a facing tool on it.
Sounds spamtastic.

You may want to have a gander at this thread, where someone with 40 years of wrenching experience said it is not needed on 90% of the bikes, and it would be noticeable if needed.

http://forums.mtbr.com/showthread.php?t=190471
 
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