Dmitry- It's kind of a judgment call. Pay attention to how parts come off the bike. Do the head set cups take "too" much force to drive out of the head tube? Do the cups and cones show even bearing track wear? Do the head tube end faces look consistent around their circumference? So to with the BB. Did the cups unthread smoothly, was there any gaps under the fixed cup lip or lock ring before removal, do the threads and end faces look nice, are the wear tracks even?
Chasing and facing only removes material so care should be used that they are done only to correct, not create, problems. Additionally care should be taken to not chip off paint during the facings. I "break" the paint around corners with a fine file first.
I have chased and faced the same frames two or three times over the years and each time the facing showed slight unevenness had existed before. Yet the same tools and techniques were used (I've owned my own Campy tool kit since 1980). I think I could repeat any number of times and still see a very slight change each time.
So it's all about the judgment and that starts with the condition of the frame.
Do you have a particular situation you're concerned with? If so can you provide more detail?
> Hi,
>
> When you build up an old frame, or change BB or headset - do you
> usually re-face (and in the case of headset, perhaps re-ream) the
> tubes? Or are those procedures only needed for new frames? Please
> share your experiences.
>
> --
> Cheers,
> Dmitry Yaitskov,
> Toronto, Canada.
>
> _______________________________________________
Andrew R Stewart
Rochester, NY