Results 1 to 6 of 6
  1. #1
    RoadBikeReview Member
    Reputation: mwestray's Avatar
    Join Date
    Jan 2008
    Posts
    48

    deteriorating finish on Chorus UT 10-spd crankarms?

    Have been running a Chorus 10-spd UT crankset (compact) for 4+ years with absolutely no performance issues. I am pretty meticulous with my bike and clean it frequently; usually just a 5-minute wipe down is enough since I don't let the grime build up. A while back I noticed that NDS crank arm had some dull-looking areas instead of the glossy finish. I didn't think too much about it, assuming it was just shoe rub, etc. Recently though, I noticed that the end of the NDS arm has developed a white-ish appearance. Yesterday while cleaning the bike after getting caught in a rain storm, I noticed some white spots on the side of the NDS arm. There are no chips in the clear coat, these spots and discolorations appear to be beneath the clear coat and/or within the carbon fiber matrix itself. So far this is mostly on the NDS arm, although the DS spider and arm are starting to show some of the dull areas like I initially notices on the NDS arm. I assume that there is nothing wrong structurally, but I am disappointed that the fine Campy finish is showing age (similar to the rider!). Have any other Campy owners experienced this issue? If so, are there any corrective actions, besides investing in a new crankset?

  2. #2
    RoadBikeReview Member
    Reputation: velodog's Avatar
    Join Date
    Sep 2007
    Posts
    3,057
    If, indeed, the cranks are structurally sound I wouldn't worry about it none. Call it patina and ride hell out of it.

    I appreciate honest wear on my equipment, so don't worry much about such things. Signs of use, not abuse, add character.

  3. #3
    RoadBikeReview Member
    Reputation:
    Join Date
    Feb 2004
    Posts
    10,126
    Quote Originally Posted by mwestray View Post
    are there any corrective actions, besides investing in a new crankset?
    You could remove the chainrings and thoroughlt sand the crankarms to remove any discoloration, then apply several coats of clear, catalyzed urethane. You can get catalyzed urethane in a spray can.

    SprayMax 2K Urethane Aerosol Clear Coat

    I'd use Norton 3X 400 grit sandpaper. It works dry and removes material quickly. A final wet sanding with 600 grit silicon carbide paper might be wise, prior to painting.

  4. #4
    classiquesklassieker
    Reputation: orange_julius's Avatar
    Join Date
    Jan 2003
    Posts
    3,068
    Quote Originally Posted by C-40 View Post
    You could remove the chainrings and thoroughlt sand the crankarms to remove any discoloration, then apply several coats of clear, catalyzed urethane. You can get catalyzed urethane in a spray can.

    SprayMax 2K Urethane Aerosol Clear Coat

    I'd use Norton 3X 400 grit sandpaper. It works dry and removes material quickly. A final wet sanding with 600 grit silicon carbide paper might be wise, prior to painting.
    Can this same procedure be used to touch up a carbon rear derailleur body that has been scratched up?

    Thanks!

  5. #5
    RoadBikeReview Member
    Reputation:
    Join Date
    Feb 2004
    Posts
    10,126
    Quote Originally Posted by orange_julius View Post
    Can this same procedure be used to touch up a carbon rear derailleur body that has been scratched up?

    Thanks!
    Sure, but I wouldn't bother with pricey urethane, just use cheap spray lacquer. The urethane spray can is a one-time use. Once the catalyst is activated, the paint has a short life. It will harden, even in the can.

  6. #6
    classiquesklassieker
    Reputation: orange_julius's Avatar
    Join Date
    Jan 2003
    Posts
    3,068
    Quote Originally Posted by C-40 View Post
    Sure, but I wouldn't bother with pricey urethane, just use cheap spray lacquer. The urethane spray can is a one-time use. Once the catalyst is activated, the paint has a short life. It will harden, even in the can.
    Good tip, thanks!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Hot Deals

Contest

Tour De France

Latest RoadBike Articles


Latest Videos

RoadbikeReview on Facebook