Advertise on Bikeforums.net



User Tag List

Results 1 to 10 of 10
  1. #1
    Junior Member
    Join Date
    Jun 2011
    Posts
    7
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Frankenbike problems

    Hey all,

    I recently built a frankenbike from lots of pieces from lots of bikes about to be abandoned, or already abandoned. So far it's working fine except when I ride over a bump, it shifts down one on the rear cog. I was thinking that it might have something to do with the derailleur cable tension, but honestly I have no idea. This is the first bike I've ever built. Any suggestions?

    Thank you!

  2. #2
    Lover of Old Chrome Moly Myosmith's Avatar
    Join Date
    May 2011
    Location
    NW Minnesota
    Posts
    2,544
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Tell us more about the bike. Type of shifters? Derailleurs? ect. Close up pictures of the shifters, cable arrangements, and drivetrain would be helpful.
    Lead, follow or get out of the way

  3. #3
    Junior Member
    Join Date
    Jun 2011
    Posts
    7
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Myosmith View Post
    Tell us more about the bike. Type of shifters? Derailleurs? ect. Close up pictures of the shifters, cable arrangements, and drivetrain would be helpful.
    IMG_0030.jpgIMG_0031.jpgIMG_0032.jpg
    Cables are all new. The rear derailleur, I believe, was the one initially attached to the bike.
    Last edited by littlerobin; 05-01-12 at 11:15 PM. Reason: Added info.

  4. #4
    Senior Member WickedThump's Avatar
    Join Date
    Mar 2012
    Location
    Aurora, Colorado
    My Bikes
    Kona JTS Frankenbike
    Posts
    542
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Since you replaced the cable,(and checked it for sticking?), I'd guess the derailer is sticking, possibly from a loose or worn fastener on it.
    Take it off, inspect, clean, and lube it. You might want to just hose it with WD40 or similar, and see if that helps.

  5. #5
    Senior Member
    Join Date
    Aug 2005
    Location
    Pittsburgh, PA
    My Bikes
    '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
    Posts
    25,970
    Mentioned
    10 Post(s)
    Tagged
    0 Thread(s)
    Adjust the tension on the shift levers. If it is insufficient they will move when you hit a bump. Tighten the hold down bolts.

  6. #6
    Junior Member
    Join Date
    Jun 2011
    Posts
    7
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thank you. I'll try those, ride today, and hopefully the problem will be solved

  7. #7
    biked well well biked's Avatar
    Join Date
    Jul 2005
    Posts
    6,876
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by HillRider View Post
    Adjust the tension on the shift levers. If it is insufficient they will move when you hit a bump. Tighten the hold down bolts.
    +1. Friction shifters have to have enough "friction" to hold the cable in its position, despite the fact that the derailleur's spring wants to move it.

  8. #8
    Senior Member IthaDan's Avatar
    Join Date
    Jan 2012
    Location
    Ithaca, NY
    My Bikes
    Click on the #YOLO
    Posts
    4,651
    Mentioned
    8 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by well biked View Post
    +1. Friction shifters have to have enough "friction" to hold the cable in its position, despite the fact that the derailleur's spring wants to move it.
    +2 one of my favorite blank stare, mouth agape "fixes" at the coop for a bike that doesn't hold low gears. No tools needed.

    OP: we're all talking about tightening this guy, circled in this pic-


    Shimano : Click :: Campy :: Snap :: SRAM : Bang

  9. #9
    Senior Member
    Join Date
    Aug 2005
    Location
    Pittsburgh, PA
    My Bikes
    '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
    Posts
    25,970
    Mentioned
    10 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by IthaDan View Post
    +2 one of my favorite blank stare, mouth agape "fixes" at the coop for a bike that doesn't hold low gears. No tools needed.
    Anyone who ever used Campy's old Record downtube shifters soon learned to keep the D-rings tight. These things were notorious for spontaneous loosening and allowing "ghost shifting", always at the worst possible time.

  10. #10
    Junior Member
    Join Date
    Jun 2011
    Posts
    7
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thank you all so much! I tightened those little guys and had a much better time riding today, even got muddy

Posting Permissions

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