De Rosa BB scratches

cld531c
cld531c Posts: 517
edited December 2017 in Workshop
27352267849_db0b1dcb6f_o.jpgDeRosa2 by Claire Dwyer, on Flickr

38419801534_65ec068ecd_o.jpgDe Rosa1 by Claire Dwyer, on Flickr

Does this look right to you? It looks like it has been scoured (only done about 20 miles!)
Thanks

Comments

  • fenix
    fenix Posts: 5,437
    What are we looking for ? Those marks on the metal of the outside of the BB ? I can't say I've ever looked that closely.
    Nothing could be rubbing it as it rotates can it ?? Cos that would be wrong - but other than that...
  • veronese68
    veronese68 Posts: 27,252
    It looks a bit like what I'd expect after facing a threaded bottom bracket shell, but that doesn't look like it's threaded. Is the non-drive side the same? Can you see anything rubbing that would cause it?
  • Matthewfalle
    Matthewfalle Posts: 17,380
    Was it like that before the bb was fitted and/or immediately afterwards prior to the bike being ridden?

    As V says, looks like facing marks but I don’t know whether that is a threaded/non threaded bb.

    Any scraping/movement/etc when spinning the cranks by hand?
    Postby team47b » Sun Jun 28, 2015 11:53 am

    De Sisti wrote:
    This is one of the silliest threads I've come across. :lol:

    Recognition at last Matthew, well done!, a justified honour :D
    smithy21 wrote:

    He's right you know.
  • cld531c
    cld531c Posts: 517
    edited December 2017
    Thanks for the responses.
    I bought the bike fully built. I didnt really notice it at first as its not really a place you would look. The vendors responses have been

    1. The bare metal that you can see is actually part of the BB shell that is bonded into the frame. This is perfectly normal to be able to visually see the lip of this extending from the bottom bracket shell.

    This is the external lip of the shell that the press fit BB fits into to secure it into the frame and hold the chain set in place. I can confirm that this is how it is supposed to look from the factory and that this is perfectly safe to continue riding the bike.

    and when I pointed out that it was the scratches and rough surface that concerned me (not the lack of paint)....

    2.In this case the only way that this surface can become scratched is for the chain to drop off the 34t ring on your chain set and catch the edge of the BB shell on its way down. If this has happened while you have been on the bike then you would definitely know about it as you would have lost all drive and would have had to put the chain back on the ring to be able to ride again.

    These BB shells do not come as a highly polished finished item like a chain or cassette. If the chain does drop off the 34t small ring, (which at some point during the bikes life probably will) then the leading face of the BB shell will be scratched instantly which is why they do not finish it. By Finish I meant sand and polish to a high luster.

    This is perfectly normal, I have included a picture of a brand new De Rosa frame with the same BB set up that has the one you have which shows the unfinished effect as well.

    I havent dropped the chain and am just concerned something may not have been set up properly. If it is just cosmetic then no biggie as i dont tend to look down there"!

    EDIT Nothing seems to catch when spinning by hand but concerned that may be different when under pressure...
  • cld531c
    cld531c Posts: 517
    And it has a 36 not a 34 which I would have thought they should know :-)
  • veronese68
    veronese68 Posts: 27,252
    In that case the honest answer would have been that they don't bother finishing that bit nicely as they don't expect people to look at it. If anything was rubbing enough to gouge the metal you'd feel and hear something.
    If you want to be certain put a thin smear of something that you can wash off over the surface before you go for a ride. Look at it again after your ride and see if any of it has been rubbed off. If it look the same just wash it off. I'm almost certain it's fine though.
  • cld531c
    cld531c Posts: 517
    Veronese68 wrote:
    In that case the honest answer would have been that they don't bother finishing that bit nicely as they don't expect people to look at it. If anything was rubbing enough to gouge the metal you'd feel and hear something.
    If you want to be certain put a thin smear of something that you can wash off over the surface before you go for a ride. Look at it again after your ride and see if any of it has been rubbed off. If it look the same just wash it off. I'm almost certain it's fine though.


    Thanks - good idea
    Thinking sudocrem would go nicely with the frame :-)
  • fenix
    fenix Posts: 5,437
    And double up if you get a sore bum.
  • imposter2.0
    imposter2.0 Posts: 12,028
    Still not sure what I'm supposed to be looking at. Everything I can see in the pics looks perfectly normal to me.
  • cld531c
    cld531c Posts: 517
    Apparently all is well they just dont finish that area off properly cos they think no one will notice! Thanks again for the helpful replies
  • Matthewfalle
    Matthewfalle Posts: 17,380
    Any chance of pics of the whole bike for De Rosa nosiness purposes?
    Postby team47b » Sun Jun 28, 2015 11:53 am

    De Sisti wrote:
    This is one of the silliest threads I've come across. :lol:

    Recognition at last Matthew, well done!, a justified honour :D
    smithy21 wrote:

    He's right you know.
  • cld531c
    cld531c Posts: 517
    Any chance of pics of the whole bike for De Rosa nosiness purposes?

    24293420287_026c9ec762_o.jpgDe Rosa by Claire Dwyer, on Flickr

    Of course....Since pic bars lowered, pedals and cages changed and saddlebag removed! (paving still grubby though!)
  • Matthewfalle
    Matthewfalle Posts: 17,380
    cld531c wrote:
    Any chance of pics of the whole bike for De Rosa nosiness purposes?

    24293420287_026c9ec762_o.jpgDe Rosa by Claire Dwyer, on Flickr

    Of course....Since pic bars lowered, pedals and cages changed and saddlebag removed! (paving still grubby though!)


    Very cool - hat.

    You’ve gone the right way with the lowering/removal: it’s a De Rosa not some shonky Trek. Not designed to have junk all over it.

    Top work!
    Postby team47b » Sun Jun 28, 2015 11:53 am

    De Sisti wrote:
    This is one of the silliest threads I've come across. :lol:

    Recognition at last Matthew, well done!, a justified honour :D
    smithy21 wrote:

    He's right you know.
  • veronese68
    veronese68 Posts: 27,252
    cld531c wrote:
    (paving still grubby though!)
    Got your priorities right then.
  • cld531c
    cld531c Posts: 517
    Thank you- just need to get it off the turbo and on the road!