Do I need a set back seat post?

[tuxbailey]

Currently the clamp is close to the bend of the saddle rail (it was even closer with the Toupe.)

Is the benefit only in aesthetic or it will have some functional benefit as well.

Thanks in advance.

http://tuxbailey.zenfolio.com/img/s4/v62/p1368969215-5.jpg

[azrider]

I think you need bigger frame :p

[eBAUMANN]

I think you need bigger HEADTUBE :p

ftfy ;)

[572cv]

A fit would tell you whether you need setback on this bike. Its about your stretch over, the position of your knees as they rotate relative to the cranks, how much your legs open and close (angle). It all has an impact on the efficiency of your effort. So, you ask a complex question....you might need a setback, or not.

[Avincent52]

I think you need bigger frame :p

Funny how that works
If you just printed the photo and folded it in half midway down the top tube, the "rear" photo might suggest he needs a smaller frame given how little seatpost is showing.
But the front half, showing the stem, would make you think that OP might need a larger frame.

But to address his oriignal question, isn't fore-aft saddle about getting your torso over the bike and getting your knee over the pedal (the controversial KOPS) when you're riding?

cheers
Allen

[David Kirk]

If you are pleased with the current fit and have no plans to move the saddle rearward then changing to a set back post will not provide an real benefit unless you like the way it looks.

Of course if you want to move it back some then you'd really wants a set back post to get you there.

dave

[tuxbailey]

Well the current set up is set up by my fitter and I don't have any complaints on that. And I was asking mainly for the aesthetic POV and not taking account that a set back seat post will also affect the position of my knees, etc.

As a result I think I will just leave things be. Nah I don't need a bigger frame, more like a smaller one if I have to do it all over again.

Edit: A setback post probably won't affect my fit if the saddle remains in the same position. So it is aesthetics after all.

[Lewis Moon]

If you are pleased with the current fit and have no plans to move the saddle rearward then changing to a set back post will not provide an real benefit unless you like the way it looks.

Of course if you want to move it back some then you'd really wants a set back post to get you there.

dave

What Dave says. From what I see, the clamp is currently just a bit in front of the midpoint of the saddle (as opposed to the rails). I can't think of a reason to get a setback.

[David Tollefson]

A little more than aesthetics, you want the seatpost clamp on the rails directly under where the center of your weight is applied -- otherwise you're imposing a bending moment on those rails which increases the load and decreases their lifespan. Think of it this way: ideally you want the clamp directly under the center of your weight on the saddle, but that center should be in line with the seatpost/seat tube. The resultant offset of that is the offset you want in the seatpost. In graphic form:
http://www.beginnertriathlete.com/discussion/photos/get-photo.asp?photoid=154667

[R3awak3n]

/\ this. You dont want to be too far out of the rail limit line because hmmmmm, saddle rails might crack.

[pdmtong]

What Dave Kirk says

If your fit is good then leave the seat post as is

Your set up is for riding not for pro looks

So go ride

If you are caring about pro aesthetic then there are other places to work on first before the seat post

It does look to me as well like that may not be the best frame size for you

[macaroon]

I would try another fitter; the bars don't look right. How do you climb out of the saddle with them like that?

I'd have thought a flat bar hybrid would probably be a better bike.

[Mark McM]

A small counterpoint:

How much do you weigh? If you are a lightweight rider, and unlikely to break saddle rails, then mounting the saddle all the way back on the rails will allow a little more flex in the rails, producing a little more "give", producing a little more ride compliance at the saddle.

[Louis]

A little more than aesthetics, you want the seatpost clamp on the rails directly under where the center of your weight is applied -- otherwise you're imposing a bending moment on those rails which increases the load and decreases their lifespan.

In theory yes, but I would think that a saddle manufacturer has analyzed and/or tested their saddles such that you can safely clamp it anywhere along the "straight" portion of the rails.

I don't know how often others have had problems with breaking saddle rails, but it's never been an issue for me.

As long as you aren't, say, well over 200 lbs or aren't using this to do jumps on an MTB, I think you can pretty much use the entire length of the rail without an issue.

[simonov]

Personally, I'd never feel comfortable riding the saddle that far from the middle of the rails and would probably go with a setback post. Maybe not a 25mm setback, but something like a PMP with 14mm. Enough to move the clamp towards the middle of the rails without changing your position.

[velotrack]

^Thomson's are 16mm IIRC. That could work.

[dpk501]

Is this set up because of a bad back? It looks like mine after my back surgery.

I would go set back. Maybe the Moots post? It would look great!

I would try another fitter; the bars don't look right. How do you climb out of the saddle with them like that?

I'd have thought a flat bar hybrid would probably be a better bike.

[carpediemracing]

I have no real empirical proof of this but my thought is that clamping the saddle in the middle of the rails would be better than clamping them at one end or the other. From a structural point of view it would distribute weight better. It's easier to hold a 2x4 at the middle, not at one end.

[rustychisel]

You don't 'need' a setback seatpost if you're happy with setup, but as Dave Tollefson and others have pointed out, it's structurally better.

I have broken a saddle this way - hit a bump I didn't see - ripped the rails out of the nose of a F'i'zik Pave. Having the clamp area that far forward allows a pretty good lever to form when your weight is hard-transferred to the rear of the saddle. It might not happen, but it is possible.

[fogrider]

what size is that frame, how long is that stem and how tall are you...never mind, the real question is do you feel like you need to push the saddle any further back? I have a set up with the saddle pushed back like that, but my handlebar is not that far forward. I know there is a fair amount of pressure from my fat butt, but have never felt any flex on my saddle. that said, I love the way a moots curved saddle looks! I don't know your riding style, but if you need to get into the handlebars and feel too compressed, you should experiment with a setback post.

[spiderwj]

I think you need a smaller frame with a taller headtube but that is not the question you asked. I would recommend a setback seat post based on your photo to protect your saddle. The further back you have the saddle relative to the clamp the more leverage your behind has on the saddle rails. I fear it is only a matter of time before the rails bend in this position.


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[tuxbailey]

Thanks for the input everyone.

I think I will seek out a setback seat post so I can position the saddle in the middle of the rails. it would be better structurally as well as aesthetic because I am about 200 lbs (centering the saddle on the rails.)

As for the fit, it works as I do centuries with no issues (no locked elbows, etc.) I do have flexibility limitation in my lower back due to previous injuries so the fitter worked with the limitation of the frame to raise the bar height to accommodate my fit.

I do think that a smaller frame size like 53-54 (this one is 55) would work better but since this one fits I will just stick with it.