Why did Trek make a 36.4mm seat tube?
11-23-11, 12:54 PM
#1
Senior Member
Thread Starter
Join Date: Nov 2011
Posts: 57
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
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?
11-23-11, 04:08 PM
#6
Tawp Dawg
Join Date: Feb 2010
Location: Anchorage, AK
Posts: 1,221
Bikes: '06 Surly Pugsley, '14 Surly Straggler, '88 Kuwahara Xtracycle, '10 Motobecane Outcast 29er, '?? Surly Cross Check (wife's), '00 Trek 4500 (wife's), '12 Windsor Oxford 3-speed (dogs')
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
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.
11-23-11, 05:12 PM
#7
Senior Member
Thread Starter
Join Date: Nov 2011
Posts: 57
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
It is 31.8. I never said otherwise.
11-23-11, 05:58 PM
#8
Tawp Dawg
Join Date: Feb 2010
Location: Anchorage, AK
Posts: 1,221
Bikes: '06 Surly Pugsley, '14 Surly Straggler, '88 Kuwahara Xtracycle, '10 Motobecane Outcast 29er, '?? Surly Cross Check (wife's), '00 Trek 4500 (wife's), '12 Windsor Oxford 3-speed (dogs')
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
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?
11-23-11, 07:44 PM
#9
Banned
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.
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 11:33 PM.
11-23-11, 10:31 PM
#10
Senior Member
Join Date: Jul 2002
Posts: 6,956
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 6 Times
in
5 Posts
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.
11-24-11, 07:43 AM
#11
Senior Member
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.
