Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Painting shell face

Reply

Old 03-13-18, 02:33 PM
  #1  
joedab
Senior Member
Thread Starter
 
Join Date: Oct 2007
Posts: 54
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Painting shell face

As part of the restoration of this frame, the drive-side of it's shell was recently faced and would like to know if this ought to be painted. Given the bottom bracket does not entirely cover this, it seems subject to the elements and therefore oxidation, though unpainted it would seem to have a better mate with the drive-side cup flange. I am currently doing touch-ups all around and so would also hit this if appropriate.
Attached Images
File Type: jpg
IMG_2323 (Large).jpg (64.5 KB, 131 views)
File Type: jpg
IMG_2324 (Large).jpg (80.8 KB, 131 views)
joedab is offline  
Reply With Quote
Old 03-13-18, 02:43 PM
  #2  
Grand Bois
Senior Member
 
Grand Bois's Avatar
 
Join Date: Mar 2005
Location: Pinole, CA, USA
Posts: 17,391
Mentioned: 21 Post(s)
Tagged: 0 Thread(s)
Quoted: 409 Post(s)
I would paint it, but first I'd prime it.
Grand Bois is offline  
Reply With Quote
Old 03-13-18, 03:50 PM
  #3  
WizardOfBoz
Generally bewildered
 
WizardOfBoz's Avatar
 
Join Date: Aug 2015
Location: Eastern PA, USA
Posts: 1,244

Bikes: 1980 Schwinn Paramount, 2014 Trek Domane 6.9, 1999 LeMond Zurich

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 410 Post(s)
I wouldn't paint it (the cup you are screwing in isn't painted, either, right?

I'd make sure it had a light coat of grease, or I'd use medium loctite to ensure that the threads remain uncorroded.
WizardOfBoz is offline  
Reply With Quote
Old 03-13-18, 04:00 PM
  #4  
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 33,797

Bikes: 8

Mentioned: 113 Post(s)
Tagged: 0 Thread(s)
Quoted: 4552 Post(s)
Only internally ring mounted Phil Wood BB leaves the BB shell face fully exposed..

but use your common sense .... ?
fietsbob is offline  
Reply With Quote
Old 03-13-18, 04:43 PM
  #5  
seeker333
-
 
seeker333's Avatar
 
Join Date: Feb 2004
Posts: 3,492

Bikes: yes!

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 139 Post(s)
Let the BB face rust first, then touch it up with the same blue paint so it'll look like the rest of the bike.
seeker333 is offline  
Reply With Quote
Old 03-13-18, 05:08 PM
  #6  
Kontact
Senior Member
 
Kontact's Avatar
 
Join Date: Apr 2011
Posts: 3,017
Mentioned: 27 Post(s)
Tagged: 0 Thread(s)
Quoted: 1778 Post(s)
Leave a layer of grease on it.
Kontact is offline  
Reply With Quote
Old 03-13-18, 09:14 PM
  #7  
desertdork
just pokin' along
 
desertdork's Avatar
 
Join Date: Aug 2008
Location: the desert
Posts: 1,095
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
If you are using a cartridge BB (such as the square taper pictured which is probable given "restoration"), why did you face the shell?

But if you're using external cups, leave the faced surface bare (excepting a film of grease).
desertdork is offline  
Reply With Quote
Old 03-14-18, 11:25 AM
  #8  
Kontact
Senior Member
 
Kontact's Avatar
 
Join Date: Apr 2011
Posts: 3,017
Mentioned: 27 Post(s)
Tagged: 0 Thread(s)
Quoted: 1778 Post(s)
Originally Posted by desertdork View Post
If you are using a cartridge BB (such as the square taper pictured which is probable given "restoration"), why did you face the shell?

But if you're using external cups, leave the faced surface bare (excepting a film of grease).
If you tighten down a cartridge and the shell is not square it will affect the bearings in the cartridge. Had it happen last month.
Kontact is offline  
Reply With Quote
Old 03-15-18, 10:10 PM
  #9  
desertdork
just pokin' along
 
desertdork's Avatar
 
Join Date: Aug 2008
Location: the desert
Posts: 1,095
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Originally Posted by Kontact View Post
If you tighten down a cartridge and the shell is not square it will affect the bearings in the cartridge. Had it happen last month.
Maybe you can explain how bearings that are housed inside a rigid cartridge body are affected by a BB shell face that is not "square?"
desertdork is offline  
Reply With Quote
Old 03-16-18, 05:22 AM
  #10  
Slaninar
Bike Gremlin
 
Slaninar's Avatar
 
Join Date: Nov 2010
Location: Novi Sad
Posts: 3,827

Bikes: Custom made on Scott Speedster frame, Custom made on a 1996. steel MTB frame (all but frame changed at least once in the past 20 years).

Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 847 Post(s)
Originally Posted by desertdork View Post
Maybe you can explain how bearings that are housed inside a rigid cartridge body are affected by a BB shell face that is not "square?"
Already (nicely and in detail) explained in this thread:

Please explain why you need a bottom bracket facing tool
Slaninar is offline  
Reply With Quote
Old 03-16-18, 10:45 AM
  #11  
3alarmer
******
 
3alarmer's Avatar
 
Join Date: Nov 2010
Location: The Big Tomato
Posts: 16,532

Bikes: old ones

Mentioned: 174 Post(s)
Tagged: 0 Thread(s)
Quoted: 11013 Post(s)
Originally Posted by Slaninar View Post
Already (nicely and in detail) explained in this thread:

Please explain why you need a bottom bracket facing tool
...wow. Thank you for pointing me to that. Epic.
3alarmer is offline  
Reply With Quote
Old 03-16-18, 12:05 PM
  #12  
desertdork
just pokin' along
 
desertdork's Avatar
 
Join Date: Aug 2008
Location: the desert
Posts: 1,095
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
That linked thread is only superficially relevant. Nowhere does it address my question.
desertdork is offline  
Reply With Quote
Old 03-16-18, 02:03 PM
  #13  
Slaninar
Bike Gremlin
 
Slaninar's Avatar
 
Join Date: Nov 2010
Location: Novi Sad
Posts: 3,827

Bikes: Custom made on Scott Speedster frame, Custom made on a 1996. steel MTB frame (all but frame changed at least once in the past 20 years).

Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 847 Post(s)
Originally Posted by desertdork View Post
That linked thread is only superficially relevant. Nowhere does it address my question.
It did address my (almost exactly the) same question, at least I was happy with the provided answers.
Slaninar is offline  
Reply With Quote
Old 03-17-18, 02:04 PM
  #14  
Kontact
Senior Member
 
Kontact's Avatar
 
Join Date: Apr 2011
Posts: 3,017
Mentioned: 27 Post(s)
Tagged: 0 Thread(s)
Quoted: 1778 Post(s)
Originally Posted by desertdork View Post
Maybe you can explain how bearings that are housed inside a rigid cartridge body are affected by a BB shell face that is not "square?"
Because the cartridge body isn't as rigid as you might believe. Most are just formed tubing - sheet metal. Put enough of a side load on a heavily torqued cup and the body will distort the few thousandths of inch necessary to cause binding in a precision bearing race. Bearings just don't have any slop in them to absorb distortion. If they did the crank arms would wobble.

Last edited by Kontact; 03-17-18 at 02:42 PM.
Kontact is offline  
Reply With Quote

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Terms of Service