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Old 10-30-15, 11:07 AM
  #4301  
Cynikal
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Originally Posted by rex615 View Post
Wait, so the seat post can only down as far as the cable?
Yup, the seatpost is cut. But look at how high the seat tube and binder are.
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Old 10-30-15, 11:20 AM
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Originally Posted by Cynikal View Post
Yup, the seatpost is cut. But look at how high the seat tube and binder are.
Structurally that is not very strong, since it subjects the extended part of the seat tube to a bending force.

Once the seat post penetrates the seat tube past the top tube and the seat stays, the loads are transferred to the frame.
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Old 10-30-15, 11:24 AM
  #4303  
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Originally Posted by rex615 View Post
Wait, so the seat post can only down as far as the cable?
That's what I was wondering.
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Old 10-30-15, 11:26 AM
  #4304  
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Originally Posted by rex615 View Post
Structurally that is not very strong, since it subjects the extended part of the seat tube to a bending force.

Once the seat post penetrates the seat tube past the top tube and the seat stays, the loads are transferred to the frame.
I think it also depends on the butting profile of the seattube used. If the butt ran past the stays I'm sure it's strong enough.
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Old 10-30-15, 12:08 PM
  #4305  
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Originally Posted by TejanoTrackie View Post
I don't think there's any cable housing, per se. There is probably a small steel tube with a nylon tube inside it that is routed inside the top tube and soldered on the ends to keep it in place.

You're probably right.


I would think notching a section of the seat post and leaving it long enough to extend past the seat stays would be a better solution than a tall mast and short post.
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Old 10-30-15, 12:16 PM
  #4306  
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Originally Posted by Cynikal View Post
I think it also depends on the butting profile of the seattube used. If the butt ran past the stays I'm sure it's strong enough.
Yes, that would help and it will probably work just fine, plus you can't beat the cool factor and the super clean look. It is just that I am not a fan of cantilevering loads like that.
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Old 10-30-15, 12:25 PM
  #4307  
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Originally Posted by rex615 View Post
Yes, that would help and it will probably work just fine, plus you can't beat the cool factor and the super clean look. It is just that I am not a fan of cantilevering loads like that.
Just out of curiosity, do you have a structural engineering background ? Your comments seem to indicate something of the sort to me.
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Old 10-30-15, 12:38 PM
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Originally Posted by TejanoTrackie View Post
Just out of curiosity, do you have a structural engineering background ? Your comments seem to indicate something of the sort to me.
On the internet, everyone is an engineer!

But yes, M.E.
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Old 10-30-15, 12:46 PM
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I was reading about this earlier this morning cause I was worried that my seatpost is too short to raise it higher. Apparently, you need at least 2 inches of the seatpost length below the top tube for it to be safe.
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Old 10-30-15, 01:19 PM
  #4310  
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Originally Posted by rex615 View Post
On the internet, everyone is an engineer!

But yes, M.E.
Yeah, I figured either C.E. or M.E. Anyways, I agree entirely that by inserting the seatpost just a couple of inches into the seat tube will greatly reduce the local bending moment in the seat tube. Sometimes seemingly elegant solutions such as this are not always the best from an engineering standpoint.
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Old 10-30-15, 08:52 PM
  #4311  
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Brian from Circle A Cycles, now just Chapman Cycles, made two bikes like this with the integrated seatpost. One was my track bike which has been posted here before and another was a cross bike with similar routing through the seatpost. Atleast on mine I have cut the post so that it extends only about 1.5-2 cm past the slot for the pinch bolt. I figured any longer and it would cause more stress on the tube itself. The butting on this specific tube is pretty thick and is also sleeved by a lug at the toptube juncture. This particular bike has been ridden and raced a ton and has been mainly a messenger bike for five or six years now and is still in great shape.
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Old 10-31-15, 04:01 PM
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Konga

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Old 10-31-15, 04:17 PM
  #4313  
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dat Chris King
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Old 10-31-15, 04:26 PM
  #4314  
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looks like folk art of a guy pissing
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Old 10-31-15, 08:51 PM
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bike art

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Old 11-01-15, 07:25 AM
  #4316  
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Originally Posted by Soil_Sampler View Post
You beat me to it!
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Old 11-01-15, 08:33 AM
  #4317  
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Originally Posted by jlafitte View Post
bike art

I like this!
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Old 11-01-15, 09:56 AM
  #4318  
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Originally Posted by rex615 View Post
On the internet, everyone is an engineer!

But yes, M.E.
But are you a French engineer?
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Old 11-01-15, 10:00 AM
  #4319  
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Originally Posted by Soil_Sampler View Post
As a parent who taught both his kids to ride bikes, I shudder to think how much was spent on something that was used for about 6 months.
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Old 11-01-15, 11:40 AM
  #4320  
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Originally Posted by Soil_Sampler View Post

Too rad.
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Old 11-01-15, 11:42 AM
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Originally Posted by jlafitte View Post
bike art

That piece, captured in B&W is giving me a David Lynch vibe. In a bad way. Which is good.
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Old 11-01-15, 12:29 PM
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Originally Posted by MadKaw View Post
But are you a French engineer?
Sorry, but I am not understanding your reference, and somehow believe I am missing out on a good joke (no problem if the joke is at my expense)
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Old 11-01-15, 07:12 PM
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Originally Posted by Noli Timere View Post
As a parent who taught both his kids to ride bikes, I shudder to think how much was spent on something that was used for about 6 months.
I know what you're saying, but I'd lying if wasn't thinking about putting carbon post and a cool seat on my boy's Giant balance bike when I bought it.
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Old 11-01-15, 08:05 PM
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Old 11-02-15, 08:36 AM
  #4325  
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