# Seatpost setback...



## Cruzer2424

Is there ever a reason to use a seatpost with zero setback? 

What advantages/disadvantages does it have?


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## Dinosaur

*Zero setback..*

Zero setback seatposts are mainly a TT bike type thing. It pushes you forward over your bars for a more aerodynamic position. If you click on photos of TT's you will see a lot of them. Although it comes down to how you position your saddle. I can use a zero setback with certain saddles, but I have to push the saddle way back in it rails to get back far enough. Most roadies ride with their saddle pushed way back as it is supposed to be more comfortable and putting you back gives you more power when climbing. The problem I have with Zero setbacks is that it puts my saddle in a place where it was not designed to be. It could cause damage to your rails if you have a ti railed saddle. It comes down to fit, how you like to position yourself and the geometry of your bike. You might get by with a zero setback post and maybe not. Probably better off sticking with a seatpost that offers a fair amount of setback then it allows you a lot of area to play with.


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## fast14riot

Also good for people with shorter torso's as it can help reduce the amount of stretch to the bars, but will put you further forward over the BB. I see quite a few LeMonds with zero setback posts because they have a long Top Tube dimension, but with newer compact geometry I see no reason for one on a road bike unless its a TT machine or a CX bike.


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## C-40

*yes...*

If you have a bike with a slack 72.5 degree seat tube angle like many LOOK frames with the traditional geometry, a no-setback post may be the perfect thing, depending on your desired KOP. I use one to produce a "normal" KOP with a 72.5 STA, but not if I want a further back position.

On most brands, with steeper STAs, the no setback post will position the saddle too far forward.

A short torso rider should not use this type of post to reduce the reach to the handlebars. That's what short stems are for.


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## MerckxMad

*Depends on the fit*

According to the above replies, everyone using a Thompson seatpost is improperly fit on their machines. I don't think you can make that kind of generalization. Over the years, I've been fit by top-notch shops using various sizing systems and tweeked my position as age, weight and (in)flexibility have taken their toll. I have always used a zero-offset post to stay within my "optimal" position range while varying frame size, stem length, and bar reach reach 1 or 2 cm's over the years. No matter the physio, coach, or wrench doing the fitting, we've always chucked the standard 25mm setback post for the zero-offset on every one of my machines. There is no right or wrong post to use. It depends entirely on the rider and the machine.

N.B. Beware the onslaught from the protractor gang ready to dispel everything stated above as flying in the face of geometry and physics.


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## Bill70J

*Short Femur*



Cruzer2424 said:


> Is there ever a reason to use a seatpost with zero setback?
> 
> What advantages/disadvantages does it have?


I have a long (36") inseam, but very short femur. So in order to get my desired KOP, I am forced to use a zero setback post. It puts my saddle in a mid-rail position.


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## Anti-gravity

*Yeah same here*



Bill70J said:


> I have a long (36") inseam, but very short femur. So in order to get my desired KOP, I am forced to use a zero setback post. It puts my saddle in a mid-rail position.


Short femurs. Found myself always "on the rivet" and the tip of my saddle is not too comfortable for long periods. Had my friend (professional bike fitter) fit me and one of the changes was a zero offset seatpost. And like C-40 said, no, seatpost offset should never be changed to compensate for to long/short reach. The seatpost adjusts for the legs, the stem for the torso.


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## mike2rc

I have a Felt Z25, SRAM Red compact (54) with a set back carbon seat post and I also have short femurs and longer calves. I get the sensation I'm pushing the pedals too much and sometimes get back pain and I have to stretch a little to get into the drops. A professional fitter suggested a zero degree seat post when he fitted me. I'm also on the correct stem length he measured me at - 110.

I ordered a Thomspson zero degree seat post today ($150) which is actually lighter. Is replacing the seat post better than adjust the saddle? One customer in the the shop said he got the same advice for his Canondale and difference is night and day.

Is it possible to say I'll notice a nice difference or do I have to wait and see when I get it on the bike?

Thanks,
Mike


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## C-40

*info...*

I totally ignore the knee to pedal relationship (KOP) and concentrate on weight balance over the saddle. A lot of highly regarded fitters and frame builders do the same. If you move the saddle forward, the stem should also be lengthened by the same amount, otherwise you're change two things at once and not really evaluating the change to saddle position.

The problems that can occur if the saddle is too far forward are too much weight on you hands and not using all of your available legs muscles to power the bike. A further back position will make more use of the glutes and hamstrings. You do not see very many pro riders using nonsetback posts. I made this statement a few weeks ago on another website and go several photos of what people thought were nonsetback posts on pro bikes, but every picture was of a post that did have setback. At any rate, you be assured that well over 90% of pros will use setback posts and in some case very extreme setbacks.

Read some of the articles below and see what you think.


http://www.cyclefitcentre.com/pdf final docs/backyard positioning_julu_aug_2004.pdf
http://www.cyclefitcentre.com/pdf f... NOT HAVE KNOWN ABOUT BIKE POSITION_final.pdf
http://www.peterwhitecycles.com/fitting.htm
http://www.sheldonbrown.com/kops.html


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## Mel Erickson

KOPs is useful because it gives you a place to start. A reference point. That's about it. You need to go from there to get your optimal setup. For most of us that will usually entail further adjustment to the rear but not necessarily. Without access to fairly sophisticated equipment and analytical techniques it's awfully difficult for the average joe to assess whether a change from KOP is beneficial or not. We simply have to go by feel. Even fairly simple pieces of equipment like a Powertap hub are not available to the average joe and would still entail a fair amount of testing and time to determine if adjustments really make a difference.

I think the best we can do is read the studies, apply them as best we can to our own situation and go by feel when making adjustments. Therefore, I am not an advocate of straight seatposts as I think the majority of us can benefit from setback, based on the studies and how it feels to me on the bike. YMMV because your body is different from mine.


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## mike2rc

Thanks for the info. I just cancelled the zero degree Thompson seat post before reading your reply and thought I would try moving my saddle forward a tad.

If I read you right, I'm better off with my current Felt 1.2 carbon, 27.2 x 300mm seat post which is not zero degree...correct me if I'm wrong.

Thanks!
Mike


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## Mel Erickson

mike2rc said:


> Thanks for the info. I just cancelled the zero degree Thompson seat post before reading your reply and thought I would try moving my saddle forward a tad.
> 
> If I read you right, I'm better off with my current Felt 1.2 carbon, 27.2 x 300mm seat post which is not zero degree...correct me if I'm wrong.
> 
> Thanks!
> Mike


I can't tell if you're right or wrong. You have to be the judge. However, I agree with C40 that most people are better served by a setback post, assuming a "normal" seat tube angle. If you're trying to get a better position over your pedals then, by all means, move your seat around. However, if you're trying to adjust for cockpit length, then moving your saddle is not the answer. A different stem could be the answer.


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## isaul1

I have had these same issues as well. I also prefer a no setback post. I have a 89cm inseam, which places the seat pretty high (around 80cm from BB). Also remember that the higher the post, the more setback you get. One thing some may overlook is crankarm length. I ride 175mm. This also places me futher foward. Your cleat position also plays a role on for/aft and height a bit. I have been through several fitters, but honestly, they are clueless as far as power and efficiency is concerned. This is what I do...Assuming that your frame size is correct, and that you are healthy with no injuries, go ride your bike on a flat road, doing a hard effort, and do it alone. Ride hard, but stable. Not a sprint. Pay attention to what your body wants to do in order to sustain your effort. Pay close attention to where you might feel excessive pressure/pain. Where do you find yourself on the seat? While pedaling, do you feel excess pressure on the knees on the bottom of your stroke? Or do you feel no pressure at all, and pain behind the knee. I always found that with a setback post, I always rode on the tip of the saddle. When I would lay down serious power, I found that I would not get good extention from my legs, experiencing knee pain and lower back pain. Some would say "Raise the seat!", but then this puts me further on the tip of the saddle, or with my knees no longer over the ball of my feet, and out of the power position. I would be reaching for the pedals. Some would say "MOVE THE SEAT FOWARD!"............ You want to get your sit bones on the wide part of the seat, without having to scoot your butt back every 30 seconds, although you do want a little play for when the road goes up.


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## bikeguy0

Long torso, shorter femurs. My knee is way behind the pedal spindle without a zero setback seatpost. I feel much more "on top of the pedal" instead of "behind it".


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## SFTifoso

bikeguy0 said:


> Long torso, shorter femurs. My knee is way behind the pedal spindle without a zero setback seatpost. I feel much more "on top of the pedal" instead of "behind it".


Sorry for the old thread bump, but I figured other riders might be benefit. Anyways I'm on the same boat. I have long tibias and short femurs. I was also having some hand numbness and elbow pain issues. Turns out I was using my arms to push me back into the saddle. My body wants to naturally slide forwar. So I dumped the stock 20 mm offset post in favor for a 10 mm offset one and the difference was like night and day. My body still wants to slide forward, but not as much as before. I'm going to get a zero offset saddle and hopefully that will completely get rid of my fit troubles.

One thing I've learned so far is that there are no rules to bike fitting. Do whatever takes to make you comfortable and able to develop the most power. Don't copy others, especially pros, listen to your own body instead.


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## C-40

*well..*

It would be interesting to know if moving the saddle further forward really helps. There are a number of respected fitters who believe that leg proportions and have nothing to do with the appropriate saddle position. They also favor a fruther back position, that usually balances the body better and eliminates excessive weight on the hands. With the proper setback you should be able to "hover" your hands over the brake hoods, or ride with a single fingertip touching the hoods.

If you've got too much weight on your hands, the solution is moving the saddle further back.


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