facing bb shell

Workshop tales, trials and disasters.
Maintenance tips, techniques and myths.
Technical discussion, description and outright lies

facing bb shell

Postby tallywhacker » Fri Dec 21, 2007 9:03 am

just had a frame powdercoated. The bb was faced before I decided to powdercoat it. Is it imperative that it be refaced to remove the paint from the fixed side before the bb is installed ? (also the same question for the headtube)
User avatar
tallywhacker
 
Posts: 1598
Joined: Thu Apr 12, 2007 3:21 pm
Location: on the road

by BNA » Fri Dec 21, 2007 9:08 am

BNA
 

Postby europa » Fri Dec 21, 2007 9:08 am

Got no idea mate. Have you tried screwing the bb in? If it screws in okay, I'd just go with it, but check it for tightness during the settling in process.

Regarding the head tube. The cups will have to be pressed in and maybe won't because of the extra thickness. I'd give it a go and if it needs too much pressure, then look at extra work.

But I'm only guessing. People who know might have a real answer. Keep us posted please as this is something others (like me) will be facing.

Richard
I had a good bike ... so I fixed it
User avatar
europa
 
Posts: 7327
Joined: Sun Jul 16, 2006 10:51 am
Location: southern end of Adelaide - home of hills, fixies and drop bears

Postby sogood » Fri Dec 21, 2007 9:29 am

Is there anything on the face of the BB? Maybe a light rub with some wet and dry is all that's needed.

The other thing to be careful of with facing the BB is how quickly it'll chew up the width of the BB. Once it goes below spec (English thread/Italian thread), your frame is toast. So only face the BB very sparingly and alway check the width before, during and after.
Bianchi, Ridley, Montague, GT, Garmin and All things Apple :)
RK wrote:And that is Wikipedia - I can write my own definition.
User avatar
sogood
 
Posts: 16906
Joined: Thu Aug 31, 2006 7:31 am
Location: Sydney AU

Postby tallywhacker » Fri Dec 21, 2007 9:58 am

sogood wrote:Is there anything on the face of the BB? Maybe a light rub with some wet and dry is all that's needed.

There is paint on the face and I was thinking that may be the best thing to do. Its just that you always read about having to face the bb.
User avatar
tallywhacker
 
Posts: 1598
Joined: Thu Apr 12, 2007 3:21 pm
Location: on the road

Postby sogood » Fri Dec 21, 2007 10:11 am

tallywhacker wrote:There is paint on the face and I was thinking that may be the best thing to do. Its just that you always read about having to face the bb.

When I built my Ridley, I asked a reputable frame builder to see if he can help me face the BB. He basically said that the frame should be true from the factory and all he would do is to use a fine wet and dry wrapped around a big wooden block to gently take the paint off. He said that a proper facing procedure would take too much material away and is not advisable unless the BB is in a bad state. Also, recently when I bought my wife's frame, the experienced LBS wrench said to just install the BB cups directly over it. The tiny bit of paint covering is inconsequential. Although I wasn't sure whether he was lazy and didn't want to do it for me or not.
Bianchi, Ridley, Montague, GT, Garmin and All things Apple :)
RK wrote:And that is Wikipedia - I can write my own definition.
User avatar
sogood
 
Posts: 16906
Joined: Thu Aug 31, 2006 7:31 am
Location: Sydney AU

Postby Mulger bill » Fri Dec 21, 2007 11:09 pm

If you had the BB shell faced before the powdercoat went on, it shouldn't be a problem, I doubt the coat would be uneven enough to throw it out.

The headtube? Sorry, no idea :oops: [guess]Maybe a bit of W&D to chamfer the inside edge slightly?[/guess]

Shaun
...whatever the road rules, self-preservation is the absolute priority for a cyclist when mixing it with motorised traffic.
London Boy 29/12/2011
User avatar
Mulger bill
Super Mod
Super Mod
 
Posts: 25554
Joined: Sun Sep 24, 2006 2:41 pm
Location: Sunbury Vic

Postby toolonglegs » Sat Dec 22, 2007 7:18 am

the thing you need to be careful of is external bb bearings cracking the paint when they are done up.If it isn't external then wont be an issue.
A block with fine wet/dry would do a basic job otherwise find a local frame builder or a shop that has one.
Image
User avatar
toolonglegs
 
Posts: 14329
Joined: Fri Jun 29, 2007 7:49 pm
Location: Somewhere with padded walls and really big hills!


Return to The Shed

Who is online

Users browsing this forum: Exabot [Bot]



Popular Bike Shops
Torpedo 7 Torpedo7 AU
Ground Effect Ground Effect NZ
Chain Reaction Cycles CRC UK
Wiggle Wiggle UK
Ebay Ebay AU



InTouch with BNA
“Bicycles BNA Twitter
“Bicycles BNA Facebook
“Google+ BNA Google+
“Bicycles BNA Newsletter