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  1. #1
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    Why does Specialized used set-back seatposts?

    I recently bought a frame on ebay, it is the same one you see here

    http://www.specialized.com/bc/SBCBkM...006&spid=21783

    I am at the point of ordering a seatpost (thomson). I see that the bike is spec'd with a setback post, is this necessary because of the geometry or something, or would a straight post be ok on this frame? Thanks

  2. #2
    Light Makes Right GV27's Avatar
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    It's just a fit thing. Setback seatpost just moves your weight backwards a bit. It's all a function of toptube length, seatpost geometry and stem length. From a technical point of view, sure you can run a straight post. From a fit point of view - that's a big "it depends".

  3. #3
    Too Much Crazy
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    A 'setback' thomson post is a bit misleading. Since the clamp design has zero offset to the post, a setback thomson post has about the same setback as most other brands 'regular' posts.

    A regular thomson post (or any other zero offset clamp design) would theoretically put you forward about 20 mm.

    But like GV27 said , its all about fit. Find the post position and height that gets you in the correct position as it relates to your pedals and go from there.

  4. #4
    Light Makes Right GV27's Avatar
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    Plus don't forget the seat can be adjusted in either setup. So if you're running a setback post with the seat slid forward, you can go to a straight post no problem. And vice-versa.

  5. #5
    Official Website Waterboy born2bahick's Avatar
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    Thomson found that by bending the post and using a zero offset seat clamp, it makes the overall package a little lighter than usinng a strait post and heavier offset clamp. My own measurements on my bikes show no difference in rider position.

  6. #6
    Light Makes Right GV27's Avatar
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    Quote Originally Posted by born2bahick View Post
    My own measurements on my bikes show no difference in rider position.
    OIC - that took me a minute to figure out. You mean no difference between the Thomson setback design and "conventional" setback designs, right? Thought for a second you meant straight fs. setback and i was like "Whatchu talkin' 'bout, Willis?".

  7. #7
    Official Website Waterboy born2bahick's Avatar
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    I mean the strait post (specialized) with offset clamp that came on my Epic. Compared to the Thomson masterpiece setback post that I put on it. There is no difference in rider position. I did the upgrade for the weight savings and the somewhat neater look.

  8. #8
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    Thanks folks. I ordered the setback. The incredible details about cycling minutia avaliable in the collective brains of this membership always amaze me.

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