Advertise on Bikeforums.net



User Tag List

Results 1 to 9 of 9
  1. #1
    Senior Member 67tony's Avatar
    Join Date
    Feb 2012
    Location
    mid-Michigan
    Posts
    527
    Mentioned
    2 Post(s)
    Tagged
    1 Thread(s)

    Clamp-on FD question

    Will a 31.8 clamp-on FD fit onto my 30mm o.d. seat tube?
    If not, does anyone sell a shim...or do I fashion my own?

    (These early 70's Schwinn Super Sport rebuilds are causing me more than a few sizing headaches!)

  2. #2
    aka Tom Reingold noglider's Avatar
    Join Date
    Jan 2009
    Location
    West Village, New York City
    My Bikes
    too many
    Posts
    19,775
    Mentioned
    69 Post(s)
    Tagged
    1 Thread(s)
    I bought a huge roll of shim stock from mcmaster.com. I'll be happy to cut you a piece if you like. This should last me a lifetime. You might be able to make a shim with a beer can. The material is very thin, and you can cut it with scissors.

    The shim stock I bought is .02" thick, 6 inches wide, and 100" long. It cost me $12.17.

    LINK
    You don't read my signature anyway, do you?

    Tom Reingold, noglider@pobox.com
    Residences: West Village, New York City and High Falls, NY
    Blogs: The Experienced Cyclist; noglider's ride blog

  3. #3
    Gearhead old's'cool's Avatar
    Join Date
    Dec 2009
    Location
    Chicago SW burbs
    My Bikes
    2 many 2 fit here
    Posts
    2,996
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The nominal shim thickness needed by the OP is 0.9mm or approximately 1/32". Hardware stores probably have sheet aluminum around this thickness, might charge several dollars for it though.
    1-1/2 wraps of 0.020" shim should work also. Lots of options.
    Geoff
    "I think that I think, therefore I think that I am"

  4. #4
    Senior Member 67tony's Avatar
    Join Date
    Feb 2012
    Location
    mid-Michigan
    Posts
    527
    Mentioned
    2 Post(s)
    Tagged
    1 Thread(s)
    Thanks for the kind offer, Tom, e-mail has been sent.

    I guess I shouldn't be turned off by the beer can method. Although rudimentary' it is probably effective. I'm growing weary of hunting for 21.1 long-throw quill riser stems and 30mm seat post clamps!

    I've read about using scotch tape...is that valid for some applications, or total hokey?
    Last edited by 67tony; 01-03-13 at 07:43 PM.

  5. #5
    Gearhead old's'cool's Avatar
    Join Date
    Dec 2009
    Location
    Chicago SW burbs
    My Bikes
    2 many 2 fit here
    Posts
    2,996
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I wouldn't use anything that soft (except as a temporary stopgap). It will tend to compress over time and lose preload.
    Geoff
    "I think that I think, therefore I think that I am"

  6. #6
    Freewheel Medic pastorbobnlnh's Avatar
    Join Date
    Oct 2005
    Location
    Trying to Ride in the NH Mountains!
    My Bikes
    Vintage Schwinns, Classy Cannondales, & an '83 Santana Tandem
    Posts
    9,155
    Mentioned
    11 Post(s)
    Tagged
    0 Thread(s)
    In my experience with the Schwinn fillet brazed seat tubes, I just went smaller, forced the band wider, and added a longer clamping bolt as needed.

    What type of FD are you using?
    Bob
    Dreaming of Summertime in NH!

    Visit my websites:
    FreeWheelSpa.com orpastorbobnlnh.com

  7. #7
    Senior Member
    Join Date
    Feb 2011
    Posts
    500
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I got curious and measured a coke can. .1 mm or .004 inches. Sounds like it's too skinny for your project. Real shim stock would be better here.

  8. #8
    Senior Member rootboy's Avatar
    Join Date
    Apr 2005
    Location
    Sand Spit East
    Posts
    12,736
    Mentioned
    74 Post(s)
    Tagged
    2 Thread(s)
    Scotch tape probably won't work unless it's built up to many layers. I've had good luck using a paint on layer, or two, of liquid plastic. Plastidip. More to protect the paint than build up thickness but the stuff is quite thick and could work for you if a few coats are used.

    Oh, and, if Tom's kind offer turns out to be too thin for you, lemme know. I have shim stock in several thicknesses and could cut you a piece. Mine is brass.
    Last edited by rootboy; 01-04-13 at 07:12 AM.
    Computers are useless. All they can give you are answers.
    P. Picasso

  9. #9
    Senior Member 67tony's Avatar
    Join Date
    Feb 2012
    Location
    mid-Michigan
    Posts
    527
    Mentioned
    2 Post(s)
    Tagged
    1 Thread(s)
    Thanks for the offer, rootboy, I'll keep it in mind.
    Pastor, I'm hoping to use a Shimano Tiagra on my son-in-law's SS, but I've yet to find a clamp-on in my size. For my orange SS I've collected a group of Suntour Sprint stuff, but have the same problem.

Posting Permissions

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