Advertise on Bikeforums.net



User Tag List

Results 1 to 11 of 11
  1. #1
    Senior Member
    Join Date
    Nov 2011
    Posts
    57
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Why did Trek make a 36.4mm seat tube?

    Most 31.8mm seat posts sit in 34.9mm seat tubes. So why did Trek go with 36.4mm on some of their bikes?

  2. #2
    Senior Member
    Join Date
    May 2008
    Location
    SoCal
    Posts
    1,247
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    because they can.....too bad for you

  3. #3
    Senior Member
    Join Date
    Nov 2011
    Posts
    57
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by merlin55 View Post
    too bad for you
    why is that?

  4. #4
    coprolite fietsbob's Avatar
    Join Date
    Jun 2010
    Location
    NW,Oregon Coast
    My Bikes
    7
    Posts
    35,792
    Mentioned
    15 Post(s)
    Tagged
    0 Thread(s)
    What did you use to get this measurement?

  5. #5
    Senior Member
    Join Date
    Nov 2011
    Posts
    57
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by fietsbob View Post
    What did you use to get this measurement?
    The internet

  6. #6
    Grim Piņata GriddleCakes's Avatar
    Join Date
    Feb 2010
    Location
    Anchorage, AK
    My Bikes
    Surly Pugsley, Surly Straggler
    Posts
    1,152
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Are you sure that interior diameter isn't still 31.8 mm? There are quite a few 36.4 mm seatpost clamps available, so apparently seat tubes with a 36.4 mm exterior diameter aren't that uncommon. It could just be a matter of thicker walled tubing.

  7. #7
    Senior Member
    Join Date
    Nov 2011
    Posts
    57
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by GriddleCakes View Post
    Are you sure that interior diameter isn't still 31.8 mm? There are quite a few 36.4 mm seatpost clamps available, so apparently seat tubes with a 36.4 mm exterior diameter aren't that uncommon. It could just be a matter of thicker walled tubing.
    It is 31.8. I never said otherwise.

  8. #8
    Grim Piņata GriddleCakes's Avatar
    Join Date
    Feb 2010
    Location
    Anchorage, AK
    My Bikes
    Surly Pugsley, Surly Straggler
    Posts
    1,152
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by thewire View Post
    It is 31.8. I never said otherwise.
    Ok, then I don't understand the point of your original question. If you understand that it's just thicker tubing, surely you can think of reasons why Trek might've used it. Increased strength of the tube comes to mind. Perhaps they were having frames with seat tube failures, and were looking to address that? Does it matter that the exterior diameter of the seat tube is larger than on other bikes?

  9. #9
    coprolite fietsbob's Avatar
    Join Date
    Jun 2010
    Location
    NW,Oregon Coast
    My Bikes
    7
    Posts
    35,792
    Mentioned
    15 Post(s)
    Tagged
    0 Thread(s)
    FWIW
    Tubes for bike frames end up being usually imperial , inches, and fraction of such.
    metric equivalency numbers get used ..

    OD, 7/8", 1", 1.125, 1.25, etc.. wall thickness varies the ID

    the C&V folks struggle to find french exclusive sizes. that round down to whole MM.
    Last edited by fietsbob; 11-23-11 at 10:33 PM.

  10. #10
    Senior Member mechBgon's Avatar
    Join Date
    Jul 2002
    Posts
    6,958
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I think you meant 31.6mm, not 31.8mm. Never seen a 31.8 on a Trek (or anything else I can recall... maybe Giant?). Anyway, I think the answer to the main question is that's just how it came out when their engineers were done picking a wall thickness for their tube.

  11. #11
    Senior Member commo_soulja's Avatar
    Join Date
    Aug 2008
    Location
    C-Ville
    My Bikes
    are fun to ride
    Posts
    1,142
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    FWIW, my old Klein also has a 36.4 OD seat tube / seat clamp and uses a 31.6 seat post. Think the 36.4 standard is typical of fat tubed aluminum frames from Trek and Klein.
    Mythical Creatures Touched Me in my Bathing Suit Area.

Posting Permissions

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