Advertise on Bikeforums.net



User Tag List

Results 1 to 8 of 8
  1. #1
    Newbie
    Join Date
    May 2007
    Location
    Vancouver
    My Bikes
    Infinite mountainbike, Wildcat Town & Country, Ernie Clements Falcon
    Posts
    4
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Transmission Twitching

    Hello fellow bikers,
    I've just tuned up the transmission on an old Falcon rally bike (which ran fine until now).
    Everything was fine when I flipped it over, and did the adjustments etc.
    It was only when I started riding it, I noticed that the rear derailler seems to jolt when a certain amount of force is applied onto the pedals, apperantly only when the highest 2 gears are in use. I'm not sure exactly what exactly is happening, but it's very frustrating because I can't generate enough force to recreate this when the bike is stationary. It's strange because the derailler and all the gears seem to be alligned.

  2. #2
    Fossil Lurch's Avatar
    Join Date
    Nov 2004
    Location
    Raleigh, NC
    My Bikes
    Fuji Club, Bianchi Bergamo, Fuji Suncrest
    Posts
    314
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    It sounds like the chain is slipping. How worn are the chain and cassette?

  3. #3
    Newbie
    Join Date
    May 2007
    Location
    Vancouver
    My Bikes
    Infinite mountainbike, Wildcat Town & Country, Ernie Clements Falcon
    Posts
    4
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The chain is fine, but if by cassette you mean the gear wheels I have to check. So you think the cahin starts to slip because it's too loose?

  4. #4
    Senior Member
    Join Date
    May 2007
    Location
    Washington, PA/Rochester, NY
    Posts
    100
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    i think he means more that the teeth on the gears are getting chipped and rounded making it harder for the chain to keep a good grip on the gears. this is less of an issue on the lower gears because there are more teeth for the chain to grab onto

  5. #5
    Newbie
    Join Date
    May 2007
    Location
    Vancouver
    My Bikes
    Infinite mountainbike, Wildcat Town & Country, Ernie Clements Falcon
    Posts
    4
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Ya that makes sense. It is a pretty old bike I think from the mid 70's. I guess for now I'll just have to not use the highest gears (and not do any speeding) until it annoys me enough to get a new wheel.

  6. #6
    Elitist Troglodyte DMF's Avatar
    Join Date
    Jun 2006
    Location
    Dallas
    My Bikes
    03 Raleigh Professional (steel)
    Posts
    6,896
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by yura
    The chain is fine...
    How do you know that it's fine?
    Stupidity got us into this mess - why can't it get us out?

    - Will Rogers

  7. #7
    Newbie
    Join Date
    May 2007
    Location
    Vancouver
    My Bikes
    Infinite mountainbike, Wildcat Town & Country, Ernie Clements Falcon
    Posts
    4
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    It doesn't appear to be damaged with small cracks and seems to be in good condition. Could it be stretched?

  8. #8
    Elitist Troglodyte DMF's Avatar
    Join Date
    Jun 2006
    Location
    Dallas
    My Bikes
    03 Raleigh Professional (steel)
    Posts
    6,896
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Chains don't stretch, but wear makes them get "longer". Measure 24 half-links (each inner and outer is a half link). A new chain will measure 12" exactly. 12 1/16" is marginal. Anything much over that is seriously worn. If the chain is badly worn, it's almost a sure bet that the cassette (small cog set) needs to be replaced too.

    http://sheldonbrown.com/chains.html#wear
    Stupidity got us into this mess - why can't it get us out?

    - Will Rogers

Posting Permissions

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