They have a 27.2x250mm and a 27.2x330mm post. I was wondering, is the extra 3" above the bend, or below the bend? Does anyone know the length of the seatpost on a '10 GF X-Calibur? I believe that would be a Bontrager SSR. All I see on the GF site is the 27.2, but it does not mention the post length. Will a longer post, going further down into the seat tube, be of any help avoiding the frame crackage issues on GF bikes over the last few years? Will a setback post put more stress on the frame?
Thomson Elite setback seatpost
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The height above the bend is the same; all the additional length is below the bend.
Thomson has tech drawings available on their site: http://lhthomson.com/docs/updated_pdfs/08_Elite_SP_SB_RevA.pdf
Too much post is better than not enough. The only penalty is the extra weight. You'll note that Thomson lists minimum insertion depths for their seatposts, but the frame may have a more conservative minimum insertion requirement. The rule of thumb is often 4" OR 1" below the TT intersection, though much of this is thrown out the window with aggressively sloping top tubes and other non-"standard" (non-triangle) bike frames. Too little insertion can either damage the frame or the seat post.
Thomson has tech drawings available on their site: http://lhthomson.com/docs/updated_pdfs/08_Elite_SP_SB_RevA.pdf
Too much post is better than not enough. The only penalty is the extra weight. You'll note that Thomson lists minimum insertion depths for their seatposts, but the frame may have a more conservative minimum insertion requirement. The rule of thumb is often 4" OR 1" below the TT intersection, though much of this is thrown out the window with aggressively sloping top tubes and other non-"standard" (non-triangle) bike frames. Too little insertion can either damage the frame or the seat post.
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Doesn't really matter what is spec'ed for the bike. Thomson Elite is available in 410mm length for straight and offset versions.
Btw...my favorite post. Only lament is the setback version is only 16mm and wish they had a higher offset version. If you are long legged and ride a smallish bike for your inseam, err on the side of a longer versus shorter post as suggested by others. Having a minimum of 100mm's of post inside the seat tube is a good thing. Like handlebars, posts can be cut down.
Btw...my favorite post. Only lament is the setback version is only 16mm and wish they had a higher offset version. If you are long legged and ride a smallish bike for your inseam, err on the side of a longer versus shorter post as suggested by others. Having a minimum of 100mm's of post inside the seat tube is a good thing. Like handlebars, posts can be cut down.
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Too long can be a problem too as the excess post may not allow the post to go far enough into the frame to place your saddle at the needed height. Bottle cage bolts and shaped tubing (either ovalized or bent) will prevent a super long post from working on many frames. A long post can be cut down; however, with a tape measure you determine if a 350mm post is long enough. If it is, go with it.DezFX said:
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