FieldEffect
11-23-11, 11:54 AM
Most 31.8mm seat posts sit in 34.9mm seat tubes. So why did Trek go with 36.4mm on some of their bikes?
General Cycling Discussion - Why did Trek make a 36.4mm seat tube?
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merlin55
11-23-11, 02:08 PM
because they can.....too bad for you
FieldEffect
11-23-11, 02:25 PM
too bad for you
why is that?
why is that?
fietsbob
11-23-11, 02:33 PM
What did you use to get this measurement?
FieldEffect
11-23-11, 02:47 PM
What did you use to get this measurement?
The internet
The internet
GriddleCakes
11-23-11, 03:08 PM
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.
FieldEffect
11-23-11, 04:12 PM
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.
It is 31.8. I never said otherwise.
GriddleCakes
11-23-11, 04:58 PM
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?
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?
fietsbob
11-23-11, 06:44 PM
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.
mechBgon
11-23-11, 09:31 PM
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.
commo_soulja
11-24-11, 06:43 AM
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.