Seatpost comfort: Setback vs. Zero

[Gartenmeister]

So because of the bikes I ride and and the particulars of my fit I am in a situation where my saddle is often positioned relatively far forward. On most of my bikes I could easily use a zero-setback post, and that option would probably be the most aesthetically pleasing. However, I own quite a few setback posts and tend to use them- often with the saddle shoved nearly all the way forward. Question is, when considering seatpost swaps/acquisitions should I tend toward zeros, or should I stick with setback for comfort? I've heard it suggested that the setbacks provide a greater degree of damping. Thoughts?

Most of my rides are >35 miles and on nearly 100% chipsealed roads, with a bit of gravel thrown in for good measure. I'll take any added measure of comfort I can get.

[Cicli]

http://www.cyclingabout.com/wp-content/uploads/2015/07/Seatpost-Damping.jpg

[sales guy]

Choice of set back or no isn't really a comfort issue so much as a fit issue. If you are someone who is pushed forward on the rails, a straight post would be the better choice fitting wise.

But if you think about a post, there is much more leverage on a setback post which would lead to more flex and potentially more comfort.

[Clean39T]

http://www.cyclingabout.com/wp-content/uploads/2015/07/Seatpost-Damping.jpg

That's a good link. It's also worth noting that Cannondale has moved to a 25.4mm setback post to add flex (and drop weight), and that a lot of MTB posts are not billed as being HiFlex - including the Syntace that bears such name: http://www.syntaceusa.com/index.cfm?pid=3&pk=2033 You'll notice that one is straight and still offers the give they are looking for..

Plus, what Sales Guy said, with the caveat that someone could build a frame around a straight post and still achieve the same setback as a more steep ST with a setback post - it's all math and angles relative to BB position, center of gravity, and crank length.

[BobO]

But if you think about a post, there is much more leverage on a setback post which would lead to more flex and potentially more comfort.

To expound on this a bit; the straight post is loaded primarialy axially, or directly in line with the post in compression. The setback post has a combination of loading both axial and bending. Since most every structural material will be stronger in compression than bending. The straight post will have virtually no deflection when loaded, the setback post on the other hand will likely have a subtle deflection (change of shape) that can lead to a bit of shock absorption.

[Ray]

To me any flex or damping you might get from a setback post is so small as to be essentially background noise. For me, it's ALL about where my butt is relative to the bottom bracket in terms of both height and setback (and saddle tilt). I use whatever post I need to get that right and it can vary by saddle. Brooks, for example, doesn't have very long rails so I'll often need a really setback post, even on a bike with a pretty shallow STA, to get a Brooks positioned right. Most other saddles have long enough rails to set it up more neutrally...

-Ray

[Gartenmeister]

If you are someone who is pushed forward on the rails, a straight post would be the better choice fitting wise.


Why? I can achieve the proper fit either way.

[sales guy]

Why? I can achieve the proper fit either way.


Well if you can achieve the proper fit, that fine then. Many people can't. Which is really how my comment was directed.

But as someone else said, the deflection is so minimal that it's doubtful you'd notice it. It would be more noticeable if you are a taller, heavier rider or if the post is out of the frame more. Again, more leverage on it to flex.

[Jad]

I would think that most 0 offset vs setback seatpost discussion/strategy re: comfort would be obviated by changes in tire pressure. I imagine you've tried lower pressure on the chipseal, etc, so sorry to trot this out if it's outside your question.

[Cicli]

Why? I can achieve the proper fit either way.

Saddle pushed all the way up on the rails could, could damage the rails.

[kingpin75s]

Whether our considerations are the same or not, I also always ride a straight post in part for fit reasons. I also generally prefer the effective STA they provide me so it works on a couple levels for me.

I run Ti posts on pretty much everything. They make a bigger difference when you have a lot of post showing, but I suspect a nice Ti post provides better comfort than any incremental gains in comfort purely from setback.

Buy nice zero setback posts and keep your rails as centered as possible.

[PacNW2Ford]

To expound on this a bit; the straight post is loaded primarialy axially, or directly in line with the post in compression. The setback post has a combination of loading both axial and bending. Since most every structural material will be stronger in compression than bending. The straight post will have virtually no deflection when loaded, the setback post on the other hand will likely have a subtle deflection (change of shape) that can lead to a bit of shock absorption.

Not true, if the saddle is in the same place relative to the seat tube/bottom bracket, the moment on the post is identical. Plus, since the post is angled, both posts have bending moments.

[BobO]

http://www.cyclingabout.com/wp-content/uploads/2015/07/Seatpost-Damping.jpg

Not true, if the saddle is in the same place relative to the seat tube/bottom bracket, the moment on the post is identical. Plus, since the post is angled, both posts have bending moments.

I agree, but, my statement was based on two assumptions.

First, in the link I quoted above, the posts noted as most comfortable have a curvature built in. In those cases of an axial member with a built in curvature bending moment is of greater concern than it is with a straight member, even if the load is in the same position relative to the anchorage.

Second, I am assuming that the reason for the offset seatpost is to move the seat farther rearward reletive to the bottom seat tube, thereby inducing the eccentric load that will cause the greater bending.

[ergott]

I would get the seatpost that allows the clamp to be closer to center on the rails. Looks like the Zipp 0 post is middle of the pack on that chart so you can have your cake and eat it too.
:beer:

[soulspinner]

I would think that most 0 offset vs setback seatpost discussion/strategy re: comfort would be obviated by changes in tire pressure. I imagine you've tried lower pressure on the chipseal, etc, so sorry to trot this out if it's outside your question.

Agree.

[colker]

It makes no difference if the saddle is where you want it to be. That´s what a seatpost does. It does not provide comfort. It holds the saddle.
GIve any money you would spend on more setaposts to charity: that will make a difference.

[oldpotatoe]

I would get the seatpost that allows the clamp to be closer to center on the rails. Looks like the Zipp 0 post is middle of the pack on that chart so you can have your cake and eat it too.
:beer:

Agree..move the saddle all the way aft or forward and maybe sacrifice some saddle rails. Don't look to the SP for increasing comfort..lost in the noise..air pressure, tire size, way more of an impact.

[Gartenmeister]

Agree..move the saddle all the way aft or forward and maybe sacrifice some saddle rails. Don't look to the SP for increasing comfort..lost in the noise..air pressure, tire size, way more of an impact.

Check out the photos and LMK if these are in rail-eating territory.

Regarding tire pressure/size- I disagree, and that is part of the reason for my original question. Like many here, I build, tinker with and ride a pile of different bikes. Suffice it to say I have some that are uncomfortably buzzy and shouldn't be. Think titanium frames with 28mm Compass extralights run at 55 psi (seriously). What I am starting to realize is that ride quality does not begin and end with a frame material, and the issue is most certainly not rendered irrelevant by fat supple tires at low pressures (although to be sure, that helps).

The seatpost question is just one piece of a larger equation. I am pretty sure wheelsets figure in here substantially, as well as handlebars. Just trying to get others' thoughts on the seatpost piece.

Interested in thoughts on the photos....

https://lh3.googleusercontent.com/mQrKJLy4v5EfLFdoSG533Lja8NQuYw_JRMr1CXtb4tvWyLPClQ BjE-Soo8lUWbrCAc9ZNgoU3Dyz0fZkZOxrGZm5ny90q0DbPpV2GKcN 0H_GQXhPe5eylc-dsaLlxRk6MM1tOhrdX03K-WqgNOCEKWZqAfP9SpKSkFi5eUFE1cojuXy5PtpOr_hC8T9liLw rCIEEbZaRYJQ2dC7eBnuqRt9QM7ffXNvgp2euSoVeO5opOXUZ7 vB3KXwScIUsBWu1Dr0r0EB0lPL38BaAHemjfGW4SXfrJEgNytW 6kVEPBpe5i4aSBJtBuH3wFp_XVpQWJFeqpSR5vcoL1tOXBQWG8 su-1mcRzFP1P3pcgeediB5acCxBu2TWMO74StoTbbrehBuUt0npNl WTt_9FdFSAXsh-oFpktkPoTSsS1Pj09--crUsz1JWsc3wMrzZdOg92BPhskSI_wsbNbarKvge16-mm3kXRzHnun5TPAnaa1qFTCAUqjULEwMXLXCFVJz22WNbfjfy8 FOULKvBNwzdSxHgsESiWhvKzc85mGXiYS5kRLn02nKL4qhBwgV ROGf4MLWl_SiyX8BKjcU6txqP9t0LqVM_1RMj4OWrlyvKPM9P3 9R5n8GU2xt8vowIii5s31Sn3jxfToVfwRi1RzhERYMGo_JxxEf c9qzIAQ817ZA=w1200-h900-no

https://lh3.googleusercontent.com/tYkwjqO19QOxvEyQVzMjoMimZ6nzfTiJJ49H_h0xIiRIFaDyLk 3OOKKNLXAfu9z-1fhc_i5PgeX4reF7FskatsNH5qeTYrCu0E-i1W5_8gZ-Qvx1qYfLHsDNfzNVAh8b-BDIlTjfwklF5Sify0qSk3FdN_U3jtvRG7yd3bYSK5OGjn7yko8 iH8mB2pN7Aw0RWVh1yMtApG59M0V179U_w-E7dGZQZVkc_8AULgOGoPEIDpXgq3C7qlLMburSGra9EjmpEUDA 0v7KCqP5vKpM_iTBFtgNw4snf7ggVdllVeQ0aWqtB9q0vedQ_G agRX61AxlPoBTCxBlLzN2_WgqMjDXjM0ommN8mbo1F4ZeN8Zu9 xYjnbPkhAIaV3mfd4Jitmg2hygyWcWqXI91eG1hPBGr-8rWLUtBBH-m40X7aQAZ0PyFhXhd2CrtEl80ndkFLIxBAqqutV2tWLqgLY2q2 PMDdbfTJ__CgwWSwsQQJwU4cNVH92kwbkrwHR7qFFRTSMagbOS vkSXCDhWKvMszIl4n7xo4KyOATvThamdYzp1RxINrS-uSpppHRCMFC3be0L-LDUhkdyWF1i_WP2hIo6a5t0td4f4Sz_7SpyuZ6-1f_vh40oczO7yIduH8hGtXtHHPaaSOSIubSyBrMA7k4XUk1Ai-Dq3lY6EUrPZVoQQ=w1200-h900-no

[Tony]

Check out the photos and LMK if these are in rail-eating territory.

Regarding tire pressure/size- I disagree, and that is part of the reason for my original question. Like many here, I build, tinker with and ride a pile of different bikes. Suffice it to say I have some that are uncomfortably buzzy and shouldn't be. Think titanium frames with 28mm Compass extralights run at 55 psi (seriously). What I am starting to realize is that ride quality does not begin and end with a frame material, and the issue is most certainly not rendered irrelevant by fat supple tires at low pressures (although to be sure, that helps).

The seatpost question is just one piece of a larger equation. I am pretty sure wheelsets figure in here substantially, as well as handlebars. Just trying to get others' thoughts on the seatpost piece.

I agree with this, however really depends on the length, width and material of the post.
On some MTB rides I can see long extended SPs, Ti and carbon really move with the riders pedal stroke. I don't see this on the road with the shorter extensions common on road bikes. Tires and wheel play the biggest roll making the SP a very small piece of the equation, if any. A 31.6 SP showing 6" to 7" inches will not be apart of the equation, at least not anything we would be able to feel. The saddle/saddle rails may play a bigger roll than the SP.

[chiasticon]

I would think that most 0 offset vs setback seatpost discussion/strategy re: comfort would be obviated by changes in tire pressure. this.

I would get the seatpost that allows the clamp to be closer to center on the rails.and this.

just get your ass in the right spot, first and foremost. that'll affect comfort more than anything else. then, unless you're slammed on the rails, changing posts to get you more centered is mainly just an aesthetics thing.

[mvpmp90]

I prefer setback, but that's mainly because it gets the saddle a bit further back on my track build so it's much more comfortable for me.

[zap]

Comfort is in proper fit which in most cases means an offset seatpost. Efficiency demands a proper stiff seatpost.

[notsew]

As another variable, I wonder if having the clamp closer to the center of the saddle rails provides more flex from the saddle rails than having the clamp at a far end? It seems intuitive that having the lever point be away from the turn of the rail might add more flex.

I've got nothing to back this up, just struck me looking at the pictures.

[simonov]

Check out the photos and LMK if these are in rail-eating territory.

Regarding tire pressure/size- I disagree, and that is part of the reason for my original question. Like many here, I build, tinker with and ride a pile of different bikes. Suffice it to say I have some that are uncomfortably buzzy and shouldn't be. Think titanium frames with 28mm Compass extralights run at 55 psi (seriously). What I am starting to realize is that ride quality does not begin and end with a frame material, and the issue is most certainly not rendered irrelevant by fat supple tires at low pressures (although to be sure, that helps).

The seatpost question is just one piece of a larger equation. I am pretty sure wheelsets figure in here substantially, as well as handlebars. Just trying to get others' thoughts on the seatpost piece.

Interested in thoughts on the photos....

https://lh3.googleusercontent.com/mQrKJLy4v5EfLFdoSG533Lja8NQuYw_JRMr1CXtb4tvWyLPClQ BjE-Soo8lUWbrCAc9ZNgoU3Dyz0fZkZOxrGZm5ny90q0DbPpV2GKcN 0H_GQXhPe5eylc-dsaLlxRk6MM1tOhrdX03K-WqgNOCEKWZqAfP9SpKSkFi5eUFE1cojuXy5PtpOr_hC8T9liLw rCIEEbZaRYJQ2dC7eBnuqRt9QM7ffXNvgp2euSoVeO5opOXUZ7 vB3KXwScIUsBWu1Dr0r0EB0lPL38BaAHemjfGW4SXfrJEgNytW 6kVEPBpe5i4aSBJtBuH3wFp_XVpQWJFeqpSR5vcoL1tOXBQWG8 su-1mcRzFP1P3pcgeediB5acCxBu2TWMO74StoTbbrehBuUt0npNl WTt_9FdFSAXsh-oFpktkPoTSsS1Pj09--crUsz1JWsc3wMrzZdOg92BPhskSI_wsbNbarKvge16-mm3kXRzHnun5TPAnaa1qFTCAUqjULEwMXLXCFVJz22WNbfjfy8 FOULKvBNwzdSxHgsESiWhvKzc85mGXiYS5kRLn02nKL4qhBwgV ROGf4MLWl_SiyX8BKjcU6txqP9t0LqVM_1RMj4OWrlyvKPM9P3 9R5n8GU2xt8vowIii5s31Sn3jxfToVfwRi1RzhERYMGo_JxxEf c9qzIAQ817ZA=w1200-h900-no

https://lh3.googleusercontent.com/tYkwjqO19QOxvEyQVzMjoMimZ6nzfTiJJ49H_h0xIiRIFaDyLk 3OOKKNLXAfu9z-1fhc_i5PgeX4reF7FskatsNH5qeTYrCu0E-i1W5_8gZ-Qvx1qYfLHsDNfzNVAh8b-BDIlTjfwklF5Sify0qSk3FdN_U3jtvRG7yd3bYSK5OGjn7yko8 iH8mB2pN7Aw0RWVh1yMtApG59M0V179U_w-E7dGZQZVkc_8AULgOGoPEIDpXgq3C7qlLMburSGra9EjmpEUDA 0v7KCqP5vKpM_iTBFtgNw4snf7ggVdllVeQ0aWqtB9q0vedQ_G agRX61AxlPoBTCxBlLzN2_WgqMjDXjM0ommN8mbo1F4ZeN8Zu9 xYjnbPkhAIaV3mfd4Jitmg2hygyWcWqXI91eG1hPBGr-8rWLUtBBH-m40X7aQAZ0PyFhXhd2CrtEl80ndkFLIxBAqqutV2tWLqgLY2q2 PMDdbfTJ__CgwWSwsQQJwU4cNVH92kwbkrwHR7qFFRTSMagbOS vkSXCDhWKvMszIl4n7xo4KyOATvThamdYzp1RxINrS-uSpppHRCMFC3be0L-LDUhkdyWF1i_WP2hIo6a5t0td4f4Sz_7SpyuZ6-1f_vh40oczO7yIduH8hGtXtHHPaaSOSIubSyBrMA7k4XUk1Ai-Dq3lY6EUrPZVoQQ=w1200-h900-no

Not an expert opinion, but that top photo would make me a little nervous. But I'd ride the bottom one, with the clamp within the ruled markings on the rails.

[luglust]

There's different schools on fit and seat setback etc. Its what works for your body and the bike your riding. I have long femurs and lots of slow twitch fiber. A seat post with good setback and a seat with a lot or rail length works. I climb well and spin seated strong and steady. (i used to). What works for Joe Blow might not be for you. Experiment with seat post n saddles.

[luglust]

regarding the 2 pictures above. The top is an alloy, the bottom carbon.

The alloy probably needs less visible material but the strength is there,maybe more weight than carbon.

The carbon post, different material/design. Metal seat rail clamps on carbon post.

Cant tell a seat post by looking at the cover. I'd ride that Ritchey seatpost anyway.

[sales guy]

The other issues are those two posts aren't the same setback. The Ritchey is a 25mm and the carbon looks to be 15mm. So that will cause the rails to be more centered on the clamp. So comparing apples to oranges ins't the best.

[rwsaunders]

I found this quote from Dario Pegoretti to stir things up a bit..."And last thing, maybe someone understand that I do not like the straight post, my eyes refuse to watch them, maybe I'm too old?"

[steelbikerider]

Velonews did a comparison test a few years ago with seatposts and found there was a measurable difference in flex between straight and setback posts. here
http://www.velonews.com/2012/12/training-center/technology/from-the-pages-of-velo-getting-the-most-from-your-post_267560

[Gartenmeister]

The other issues are those two posts aren't the same setback. The Ritchey is a 25mm and the carbon looks to be 15mm. So that will cause the rails to be more centered on the clamp. So comparing apples to oranges ins't the best.

Not comparing anything. Just two examples of actual setups I ride, submitted for comment on acceptability.

[sales guy]

Not comparing anything. Just two examples of actual setups I ride, submitted for comment on acceptability.

Wasn't a slam or anything. Just mentioning the differences was all.

[luglust]

Gartenmeister ,X2 agreed

[Wolfman]

This is (for me) all about weight distribution/butt placement first, then aesthetics second.

I will say that I like setback with a radiused fork and a zero degree with a straight blade; I submit what I think is a great example of the former. If you can have this and have your weight where the frame does its thing, you're twice a winner.