Not 100% swung on the necessity to face a BB shell but I am humoring myself 😆

Will a STD BB facing tool cope with a Ti shell? Will be getting the LBS to do this as I do not have the tool but wondered ahead of booking it in 😕

Ive chased and faced the BB on my Ti road frame, no problem

Facing needs to be done is using external BB’s. For cartridge BB it is not essential. Titanium frames can be faced with normal tools but it may damage the the tool. Hense any shop is likely to bill a fair bit in case of tool damage.

Never done one my self so I cannot say how true the this is but titanium is harder to work than steels.

Facing needs to be done is using external BB’s

No it doesn’t.

No it doesn’t.

Yes it does.

(or, the faces should be flat and parallel, which they may not be from the manufacturer, to maximise EBB bearing life.)

No it doesnt. Its a waste of time and money and potentially damaging to your frame.

Not convinced it needs doing. Every Ti frame i have owned has had a very precicely made machined BB. Why would I even dream of facing something that was precision CNC machined in the first place?
Cleaning the BB threads is worth it though. My 456Ti had very dirty threads and needed them cleaned to get the bb shells to screw in cleanly.

Cleaning the BB threads is worth it though. My 456Ti had very dirty threads and needed them cleaned to get the bb shells to screw in cleanly.

thanks for your sharing ! 🙂

OK. You may get away with it as your BB may have parallel faces from the shop, but 2 bearings on a common shaft should be parallel. Anything other than this will reduce bearing life.

As another said, you probably won’t find anyone to do it for you anyway – my LBS (who I have a good relationship with) said that they won’t do Ti as it damages the tool, plus it shouldn’t need doing (my 456Ti was straight, and now 2 years on the same BB kinda proves it).

Never had anything ‘faced’ on any frames, and the bearings lasted no less than expected.

The cynic in my thinks it’s a cheeky extra revenue stream for struggling LBS..

The cynic in my thinks it’s a cheeky extra revenue stream for struggling LBS..

I’d put it down to a get out clause for BB makers.

It’s my opinion that “local” BB facing of a frame is now an outdated concept. When external BB came in 10yrs or so they were being fitted to frames that had not been manufactured with that use in mind and “might” have had a poor tolerance on the faces because it was a none issue. TBH any frame maker sending a frame out in the last decade with this problem also has a bunch of other inaccuracies in their construction that I would be equally concerned about.

any frame maker sending a frame out in the last decade with this problem also has a bunch of other inaccuracies in their construction that I would be equally concerned about.

thanks for yur sharing !

No need to face it. If you think about it it’s not the bottom bracket shell faces that align the bearings, it’s the relative orientation of the threads. The face just allows you to secure the bearing in the thread. I can’t find it now but somewhere I have a picture of a frame that had a really odd BB area that rather proves the point.

the faces should be flat and parallel

and

2 bearings on a common shaft should be parallel

So;
1. What misalignment do you typically find on a frame before it has been faced ?
2. What are the bearing manufacturer’s tolerances for radial and axial misalignment ?
3. How much do the plastic spacers compress when the cups are tightened ?

Have you got any evidence that 2 & 3 don’t overcome 1 ?