Carbon frame - chase, facing, and all that?

Anonymous
Anonymous Posts: 79,667
edited November 2011 in MTB workshop & tech
c456 frame on its way and never dealt with carbon frames before.

Now I remain unconvinced about the whole facing and chasing business anyway, but what's the deal with carbon frames? I don't know really how the BB shell works. Is it also carbon or is there a metal shell in there?

Got a spare set of GXP cups that I was planning to fit.

Likewise with headsets and head tube.

Comments

  • nicklouse
    nicklouse Posts: 50,675
    normally an alloy insert.

    headset will be an internal for carbon so will need nothing.

    the BB should be checked for parallel sides as they are often still not right.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Anonymous
    Anonymous Posts: 79,667
    Thanks.

    If they're not parallel, take it to LBS ?
  • nicklouse
    nicklouse Posts: 50,675
    well you will have to LBS it to find out when they put the tool on it.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • junglist_matty
    junglist_matty Posts: 1,731
    I usually have a brand new frame faced for headset and BB, but the C456 comes with alloy inserts and they have clean faces so I'm guessing On-One line everything up.... Couldn't be arsed with it this time round, installed headset (with homemade press) and BB, not had any problems, steerer runs nice and smooth.
  • Anonymous
    Anonymous Posts: 79,667
    Hmm, may be okay then. How would I know if it's not, other than either the BB falls apart riding or otherwise have the special tool the LBS use to check it?

    Oh, other thing is with the C456, is there an alloy insert holder for the seat post, or is it just carbon?

    Just reading around about carbon stuff and reading all the panic stories about carbon. Got an alloy post which will fit fine and I'd like to reuse but then I read stuff about electrolytic corrosion of alloy vs carbon and makes me concerned.

    Is this all mostly FUD, or of genuine concern? A spot of carbon paste would be enough perhaps?

    Mainly the build I'm doing is on the cheap reusing as many bits as I've got, and don't really want to be matching up carbon with carbon everywhere.
  • Anonymous
    Anonymous Posts: 79,667
    Just to follow up, asked On-One and they said it doesn't need facing. Looks like it's had a face anyway. There's a 'build' thread on another site stating that they felt it was well machined, both shell and the headset seats.

    I just cleaned things up with a wire brush, and put it all in. Headset fine, BB fine. After fitting the cranks it's spinning smooth and first ride seemed great.

    Got over my worries about the seat post and just shoved it in and rode with it. From what I gather it needs salt water to start the reaction between carbon and ali. I don't tend to ride in the sea (or near it), and I don't ride on roads. I'll keep the post out of the frame if left for long periods though just in case.

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