Facing Bottom Bracket
 

I just got my bike back from the LBS and they had to re-face the BB to get rid of a creak. It seemed like every time I washed my bike I was getting this creak and this time it wasn't going away. I cleaned the chain, pulled the BB, had the wheels hubs looked at, finally gave in and took it into the shop. I even took it to a different shop since my regular shop hadn't impressed me as of late. I was surprised that facing the BB was what they ended up doing and they said it was common. Only cost $20. I'm just curious to see how common, anyone else had to have this done?

The edges (faces) of the BB shell are supposed to be exactly parallel, and standard new frame preparation includes BB thread chasing/cleaning as well as facing. Head tube facing is also a good idea, for best headset bearing longevity and performance.

so do most bike shops actually do this facing when assembling new bikes in your opinion? Considering what the BS charged I can't imagine it's to complicated. But then again I was never impressed with the service dept. at the BS I bought the bike from, Supergo.

Pre-assembled factory bikes will not be faced by the bike shop. They aren't going to take it completely apart to do so and will only face these frames if there is a noticable problem.

A new bare frame, particularly a high-line one, should be faced and prepared by the maker and most good bike shops will do a quick facing job (bb and headtube) to be sure it is done right.

It's not so much complicated as you REALLY need to know what you are doing and HAVE to have the expensive special tool to do it. I still don't see how facing the BB would get rid of a creak, but if it works.

Thank you for clarifying my response, HillRider.

What does facing mean?

It means threading a special tool into the bottom bracket shell that has cutters the shave metal off of the outside edges (faces) of the shell. I makes those faces accurately flat, exactly parallel to each other and at an exact 90° to the crank spindle. Usually only the slightest bit of metal is removed.

A similar device is used to "face" and square up the headtube to assure the headset is properly aligned with the headtube and fork steerer tube.

Okies thank you so much for the help : )

Now you got me thinking..
I just order a new shimano BB (hologram) replacement for one of my bikes, as a matter of fact it should be on it’s way from Nashbar.

Bike in cuestion is a 105 eq. ‘dale, should I have my LBS to reface it before installation? Am I asking for trouble later if I skip it? Can it work *fine* without it?
Thanks.

Since I have a BB facer, I face all my BB shells. Every single frame I've ever built up except one actually needed it. This is true of frames from assembled bikes that were stripped. I don't think the factories do it all the time either. The one that didn't need it, by the way was a 2005 Pedal Force QS2 frame. It was on the money right out of the box.

If your current bottom bracket turns smoothly with out binding, it's likely your shell faces are ok.

I just acquired a new Bianchi EV3 frameset and I haven't ever built a road bike from scratch. I have done a fair amount of mountain bikes from the ground up and I have never faced a bottom bracket. This road frame is new and has paint/powdercoating on the outer edges of the BB shell. I'm pretty sure I need to have the LBS face it before assembling it, but I just want to double check with some of the more experienced builders. Is this something that should be done, or is it just something that a hyper-detail fanatic is going to worry about?

Thanks...


doug

i'd do it. it certainly won't hurt if done properly and it is the best way to go about things.

Thanks, I figured I would ask. I want to make sure I don't overlook any little things I might not be used to with a MTB build.

Is facing only needed when installing these new external bottom bracket designs?
I assume that with the internal BB bearing designs the facing won't matter so much

After the bottom bracket is faced, is the newly exposed bare metal left that way to rust?

There should not be any metal exposed once the BB is installed.

I received my new Bianchi frame this afternoon, and I decided that before I build, I want the frame prepped. I called the LBS that does a fair amount of road bike traffic to get a price for a chase and face on the bottom bracket, and I was quoted $70.

Does that sound ridiculously high for 15 minutes of labor? What does a face & chase usually cost?

:(

I always faced the bottom bracket on frames I built prior to painting, and after painting would carefully sand any lumps in the paint on the faces but leave the primer coat intact.

I would tell my dealers not to reface, but some of them did it anyway. The picture shows an old frame where spider veins of rust under the paint have made their way from the BB faces. Not life threatening, but the paint job is ruined.

http://photos1.blogger.com/blogger/2...hulman01.0.jpg

At my LBS it's $80. I guess it's like some auto dealerships where you get charged different rates for shop labor depending on whether the job can be done by the oil change monkey or whether they have to use the real mechanic who actually knows what he's doing.

That makes sense to me. I don't have any experience with facing bottom brackets, but, since I used to be heavily into old cars, I have lots of experience with rusty steel.

Wow, Dave Moulton is around!

I remember your bikes. Yours was a name people would recommend if you wanted a good quality custom built at reasonable prices.

Do it yourself with a file.Should turn out straight enough

Wow, labor is high for some of you guys. I got a face and chase at my preferred LBS recently for $35.

Face and chase should be in the $20-$30 range. If it isn't then buy the tools yourself, learn how to use them and then face and chase 10 of your friend's bikes for $20-$30 and make back your investment.

Should it be done? Yes.
Just for new installations? No.
Does it "have" to be done? Mostly not.
Can it be done more than once? Yes, but pay attention to your overall BB shell width...most BB's have a minimum acceptable BB shell width.
Does it need to be done for older self-contained systems, or just the new external bearing type BBs? Both, although I have seen sealed BBs work just fine in shells that were so bad that when swapped to external bearing type BB and crank the spindles bound solid and couldn't complete a revolution.
Can it be done with a file (the facing)? Yes. I've done it that way before. Then again I used to be a locksmith and have hand cut keys with a file before....Get some Dykum and pay attention to what you're doing.

As Dave Moulton has pointed out, lack of sightable exposure does not prevent rust (hence bolts rusting inside nut threads). It's a spurious argument.

A new modern bike frame does not need facing with the array of sealed BB cartridges which are available and which don't need accurately perpendicular shell faces to do their job. The external bearing jobs? Well they might be a different story.

BB facing arises from the need to enable smooth running of bearings and spindle in traditional-style BBs. There is only one identifiable symptom indicating a shell needs facing for this style of ball-and-race BB -- a tight/loose pattern when the spindle is turned and the bearings have been properly adjusted.

Several shops I have worked in faced everything over $400, and some did EVERYTHING. Facing is one of those details that set a shop apart from the herd, like building wheels.

And there are plenty of bike shops that build wheels and shouldn't.

I was giving my new Giant TCR C-2 her first cleaning, and notice maybe a "firm spot" while rotating the crank. It did seem to spin easier after a couple of revolutions, but it seems to me that my other bike's crank spun with much less resistance when the chain was off the bike. The Giant spec is a Race Face Cadence BB and crank. My LBS had to swap out the BB and crank as the frame that I bought is the Limited frame, but the bike was built to the C-2 spec. Should I have LBS look at it?