Advertise on Bikeforums.net



User Tag List

Results 1 to 6 of 6
  1. #1
    opinionated SOB cycletourist's Avatar
    Join Date
    Jul 2000
    Location
    Branson, Missouri USA
    Posts
    968
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Can a 7 speed rear derailleur handle 8 cogs?

    I am building a new road bike with an 8 speed wheel and I want to cannibalize whatever I can from my old 3x7 hybrid. Can I use the rear derailleur or will it not handle an 8 speed cassette? Indexing won't be an issue because I am using bar end shifters in friction mode.

  2. #2
    Veni, Vidi, Vomiti SteveE's Avatar
    Join Date
    Jun 2002
    Location
    Republic of Anaerobia
    My Bikes
    Serotta Legend Ti, Romani Columbus SL, Soma Doublecross
    Posts
    3,582
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Cycletourist,

    Can you measure the distance between the smallest and largest cogs on the two cassettes? If the distance is the same between the two, I wouldn't think you'd have any problems as long as you're using friction shifters
    "Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting ...'holy *****...what a ride!'"

  3. #3
    The Red Lantern Rev.Chuck's Avatar
    Join Date
    Apr 2003
    Location
    Raleigh NC
    Posts
    5,967
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    If you are friction shifting, you should have no problem
    Are you a registered member? Why not? click here to register. Its free, and only takes 27 seconds!
    Help out the forums, abide by our community guidelines.

    I am in the woods and I have gone crazy.

  4. #4
    JRA...
    Join Date
    Oct 2003
    Location
    philly
    My Bikes
    trek 520 & 736, DeRosa Professional, Fuji Professional, Raleigh International 3-speed, Saronni (any info people?), Humber 3-speed, Raleigh Sports, Carlton Grand Prix coming soon!
    Posts
    839
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I gave my housemate suntour retrofriction barcons and a cyclone mkII derailleur--which he shifts over a 9-speed cassette. comes a little close to the spokes but otherwise it works fine.

  5. #5
    sch
    sch is offline
    Senior Member
    Join Date
    May 2003
    Location
    Birmingham. AL
    Posts
    2,610
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I used a '70s era five speed rear der on an STI equipped 8spd without any trouble when I retroed a PX 10 with a cast off 8spd setup. (Fr der also worked
    til it broke a screw out of a casting and was replaced.) Steve

  6. #6
    My own worst nightmare
    Join Date
    Jan 2004
    Location
    Madison, WI USA
    Posts
    1,237
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I would think that even with indexed shifting, you should be okay. The detents are always in the shifter, whether it's STI/RSX, grip, crapid-firer, thumb-top or whatever. Those detents correspond with the position of each cog. As was said, if the derailleur has sufficient range, and can handle the range of cog sizes, you should be good to go.

Posting Permissions

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