Advertise on Bikeforums.net



User Tag List

Results 1 to 9 of 9
  1. #1
    Senior Member
    Join Date
    Jun 2006
    Location
    Denver
    Posts
    470
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    31.8 mm seat tube and 32 mm claim on front derailleur

    Hi folks. I have a frame that has a 31.8 seat tube (this is the outside diameter) and a campy daytona front derailleur that is 32 mm. I haven't put the derailleur on yet, but I was wondering if this would work. Seems like 0.2 mm wouldn't make much difference, but I don't want to assume. As always, thanks for the advise!

  2. #2
    cs1
    cs1 is offline
    Senior Member cs1's Avatar
    Join Date
    Feb 2004
    Location
    Clev Oh
    My Bikes
    Specialized, Schwinn
    Posts
    6,174
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    They are considered the same thing. Good luck

    Tim
    1999 Waterford RSE-11, 1995 Waterford 1200, 1989 Specialized Rockhopper Comp
    1989 Raleigh Technium, 1989 Schwinn Traveler, 1986 Specialized Rockhopper
    1984 Specialized Stumpjumper, 1986 Specialized Stumpjumper and just way too many projects to list.

  3. #3
    Senior Member
    Join Date
    Jun 2006
    Location
    Denver
    Posts
    470
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by cs1
    They are considered the same thing. Good luck

    Tim
    Thanks Tim...that is great news!

  4. #4
    cyclist/gearhead/cycli... moxfyre's Avatar
    Join Date
    Oct 2004
    Location
    DC / Maryland suburbs
    My Bikes
    Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
    Posts
    4,172
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by vinnydelnegro
    Hi folks. I have a frame that has a 31.8 seat tube (this is the outside diameter) and a campy daytona front derailleur that is 32 mm. I haven't put the derailleur on yet, but I was wondering if this would work. Seems like 0.2 mm wouldn't make much difference, but I don't want to assume. As always, thanks for the advise!
    I think they are the same thing... but if there really is a difference and the derailer is slightly too loose, use a very thin shim. A bit of electrical tape around the seat tube should be enough to fill the gap I've done it before and it works great, allows you to get a tight-fitting front derailer without crushing the paint of the seat tube.
    My bikes | Linux and Python stuff | Photo gallery

    Sheldon Brown, I miss you. Thanks for the advice, ideas, humor, and infectious enthusiasm for everything bikes...

  5. #5
    Senior Member
    Join Date
    Jun 2006
    Location
    Denver
    Posts
    470
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by moxfyre
    I think they are the same thing... but if there really is a difference and the derailer is slightly too loose, use a very thin shim. A bit of electrical tape around the seat tube should be enough to fill the gap I've done it before and it works great, allows you to get a tight-fitting front derailer without crushing the paint of the seat tube.
    hmm...not a bad idea with the electrical tape. i think i'll give that a try just so i don't chip the paint. it doesn't cause the derailleur to slide?

  6. #6
    cyclist/gearhead/cycli... moxfyre's Avatar
    Join Date
    Oct 2004
    Location
    DC / Maryland suburbs
    My Bikes
    Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
    Posts
    4,172
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by vinnydelnegro
    hmm...not a bad idea with the electrical tape. i think i'll give that a try just so i don't chip the paint. it doesn't cause the derailleur to slide?
    Nope! Because the electrical tape has a bit of give to it, the derailer clamp bites into the tape and holds very securely. I've added electrical tape to most bikes that I've built or repaired, and never had a derailer slide.
    My bikes | Linux and Python stuff | Photo gallery

    Sheldon Brown, I miss you. Thanks for the advice, ideas, humor, and infectious enthusiasm for everything bikes...

  7. #7
    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
    25,260
    Mentioned
    5 Post(s)
    Tagged
    0 Thread(s)
    Derailleur sizes are often rounded off in the manufacturer's literature. Seat tubes are 1-1/8" ( 28.57 mm, often given as 28.6 or even just 28mm), 1-1/4" (31.75 mm rounded to 32 mm) and 1-3/8" (34.92 mm or 35 mm).

  8. #8
    Extra Medium Member redtires's Avatar
    Join Date
    Jul 2006
    Location
    Louisville, Co
    My Bikes
    Fuji Roubaix 1.0 (Sampson Kalispell Ti GONE); VooDoo Wanga (Specialized Stumpy: GONE)
    Posts
    1,592
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    If you think about it, 1mm is about the thickness of a dime. So what your dealing with it 2/10ths of the thickness of a dime. Would you worry about this too much? Neither would I.

  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
    25,260
    Mentioned
    5 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by redtires
    If you think about it, 1mm is about the thickness of a dime. So what your dealing with it 2/10ths of the thickness of a dime. Would you worry about this too much? Neither would I.
    I'd worry about it when sizing handlebar-to-stem fit and seatpost-to-seat tube fit but not front derailleur clamps.

Posting Permissions

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