"Facing" bottom bracket?
#1
Ninja cyclist
Thread Starter
Join Date: Jul 2008
Location: Helsinki, Finland
Posts: 269
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
"Facing" bottom bracket?
My friend said that I'd need get my bottom bracket (new frame) "faced" before installing (or well I'm prolly gonna take it to an LBS since I dont have the tools) the bearing. Facing apparently means milling/sanding the bb faces with a special tool so they are level. Is this true and will this be expensive?
#2
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 2026 Post(s)
Likes: 0
Liked 1,095 Times
in
741 Posts
The need for facing (yes it means milling the bottom bracket shell and head tube faces to be sure they are even and perfectly square to the centerlines) depends on the frame you bought and, to a lesser amount on what bottom bracket you are going to use.
A high quality frame from a good manufacturer or custom builder should have been faced by the maker and doing it again is not needed. Look at the frame. If the shell edges are smooth and free of paint, you should be good to go. If they are rough or have overspray on them, have your LBS clean them up. It should not be very expensive but it's worth asking first. Also, pick an LBS that is familiar with good bikes. Many shops, particularly the chains, sell and service mostly cheap MTB, Hybrid and children's bikes and won't have the tools or expertise to do the facing properly. Again, ask first.
Cartridge bottom brackets aren't as alignment sensitive as the newest external cup bb's like Shimano Hollowtech II and Campy Ultra Torque so depending on what you are going to us, the advisability of facing is greater or lesser.
A high quality frame from a good manufacturer or custom builder should have been faced by the maker and doing it again is not needed. Look at the frame. If the shell edges are smooth and free of paint, you should be good to go. If they are rough or have overspray on them, have your LBS clean them up. It should not be very expensive but it's worth asking first. Also, pick an LBS that is familiar with good bikes. Many shops, particularly the chains, sell and service mostly cheap MTB, Hybrid and children's bikes and won't have the tools or expertise to do the facing properly. Again, ask first.
Cartridge bottom brackets aren't as alignment sensitive as the newest external cup bb's like Shimano Hollowtech II and Campy Ultra Torque so depending on what you are going to us, the advisability of facing is greater or lesser.
#4
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 2026 Post(s)
Likes: 0
Liked 1,095 Times
in
741 Posts
Yep.
#5
Elitist Troglodyte
Join Date: Jun 2006
Location: Dallas
Posts: 6,925
Bikes: 03 Raleigh Professional (steel)
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Hard to tell from the pic. Is that dirt, stains, or roughness?
__________________
Stupidity got us into this mess - why can't it get us out?
- Will Rogers
Stupidity got us into this mess - why can't it get us out?
- Will Rogers
#6
Ninja cyclist
Thread Starter
Join Date: Jul 2008
Location: Helsinki, Finland
Posts: 269
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
#7
Great State of Varmint
Join Date: Sep 2008
Location: Dante's Third Ring
Posts: 7,476
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 15 Times
in
15 Posts
I can't tell from the picture, but it looks shiny - so it might have been faced. Anyways, it's a simple operation to face such. But the tool is quite expensive, so many shops may lack on in their inventory. One simply screws down the cutting tool, then turns the handle about 1/4 turn. Done.
https://www.parktool.com/repair/readhowto.asp?id=106
https://www.parktool.com/repair/readhowto.asp?id=106
#8
Ninja cyclist
Thread Starter
Join Date: Jul 2008
Location: Helsinki, Finland
Posts: 269
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I can't tell from the picture, but it looks shiny - so it might have been faced. Anyways, it's a simple operation to face such. But the tool is quite expensive, so many shops may lack on in their inventory. One simply screws down the cutting tool, then turns the handle about 1/4 turn. Done.
https://www.parktool.com/repair/readhowto.asp?id=106
https://www.parktool.com/repair/readhowto.asp?id=106
#9
Elitist Troglodyte
Join Date: Jun 2006
Location: Dallas
Posts: 6,925
Bikes: 03 Raleigh Professional (steel)
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Gentle use of mill file would clean it up. Facing is more about squaring the metal tube end.
__________________
Stupidity got us into this mess - why can't it get us out?
- Will Rogers
Stupidity got us into this mess - why can't it get us out?
- Will Rogers
#10
Senior Member
Join Date: Aug 2006
Location: Perth, W.A.
Posts: 935
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
How important is it to face bearing shells when using external bearing bottom brackets like Shimano Hollowtech? Surely all that determines the alignment for those types of BBs is the axis of the BB shell thread? The squareness of the face would seem to be irrelevant (within reason) - all that will do is affect at what point the BB stops turning as it's torqued up. Or am I missing something here?
#11
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 2026 Post(s)
Likes: 0
Liked 1,095 Times
in
741 Posts
How important is it to face bearing shells when using external bearing bottom brackets like Shimano Hollowtech? Surely all that determines the alignment for those types of BBs is the axis of the BB shell thread? The squareness of the face would seem to be irrelevant (within reason) - all that will do is affect at what point the BB stops turning as it's torqued up. Or am I missing something here?
#12
Elitist Troglodyte
Join Date: Jun 2006
Location: Dallas
Posts: 6,925
Bikes: 03 Raleigh Professional (steel)
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Yeah, you're missing the point. The entire purpose of facing is to make the tube end flat and square to the axle axis. Hillrider tells you what happens if they're not square -> metal bends. Gunk like epoxy on the face can effectively make them out-of-square too.
__________________
Stupidity got us into this mess - why can't it get us out?
- Will Rogers
Stupidity got us into this mess - why can't it get us out?
- Will Rogers
#13
Senior Member
Join Date: Aug 2006
Location: Perth, W.A.
Posts: 935
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I asked the old grey-haired guy at the LBS about this, and he said he can't remember the last time he had to face a BB shell. I would bet that most new bikes today would come with shells that are adequately square for the BB they're going to be sold with, or there would be lots of bike shops complaining about the extra assembly time or remedial work. If you're talking about an older bike or a shell that's been damaged it might be a different story.
#16
cab horn
Join Date: Jun 2004
Location: Toronto
Posts: 28,353
Bikes: 1987 Bianchi Campione
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 42 Post(s)
Likes: 0
Liked 25 Times
in
18 Posts
That looks like it only needs to have that epoxy stuff removed with a rag perhaps. The BB looks plenty (even overly) faced to me. Faced doesn't mean the entire outer diameter needs to be flat - only a continuous ring.
Note the paint at 12 - 2'o clock
Note the paint at 12 - 2'o clock