Seatpost setback and aerodynamics

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sawyer
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by sawyer

AJS914 wrote:I don't understand the theory in play here. How would moving the saddle forward 25mm, for example, make you more aero?


The basic idea is to rotate forward, TT style, to (ideally) go lower and longer at the front, which keeping an acceptable seating position in relation to the BB. As state above though, there are other considerations, not least the point made by tarmakev that further forward will normally require a higher saddle position, which is likely - other things being equal - to increase drag.

I have ridden a zero setback post for a long time and have a view that the standard "Italian fit" with large amounts of setback is heavily imbued with cycling "lore" for which there is no good rationale, but clearly what works for one doesn't necessarily work for another
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Calnago
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by Calnago

I don't believe there is a "standard Italian fit" at all. Fit is fit. Weight well balanced between the wheels, good power transfer from a comfortable seated position or standing, and bars where you can reach them and function well in any of the positions, including the drops. It all comes together. For me, I've found that 20mm setback post will clamp my saddle in the middle of the rails when it is positioned exactly where I want it. I could, and have, used posts with offsets from 25mm down to 12mm and along with the seattube angle, they will all "work", but the 20mm offset ends up being "centered" and is the most aesthetically pleasing to me and provides for equal adjustment fore and aft if it was needed. I often see zero setback posts on people's bikes where the reach is clearly too stretched out for them, so they compensate by trying to get the saddle closer as opposed to using a shorter stem and/or shorter reach bars, or in the extreme a bike with geometry more suitable for their individual requirements.
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TomColnago
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Joined: Sat Sep 05, 2015 4:05 pm

by TomColnago

Well put calnago :D my fit is good but I'm tinkering for racing benefits I will keep you updated on how I find a zero offset post as I've found a cheap one to try from a local shop (merlin cycles)

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DMF
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Joined: Sat Dec 06, 2008 10:14 am
Location: Sweden

by DMF

The one thing that needs to be understood regarding riding on the rivet, is that a) you need to really put the pressure down on the pedals, thus relieving pressure from your tender nerves by means of lifting the upper body. And b) you may very well need to do some serious off-bike work on your core strength to take the added stress off of your neck, shoulders and wrists.

So it's not all just a fit question, you actually have to push very hard on the pedals too... Or as I like to put it, "there is no free cake" :)


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