Offset or non-offset seatposts

[htono]

I understand that non-offset seatposts raise ugly emotions in this space, but I struggle to understand why.
Please educate me.
Offset seatposts were the norm when materials and design led to the single bolt post, and space was needed behind the tube to locate the mechanism. It is not ideal and places nonlinear stresses on the seat tube. I understand that frame fitting evolved around the unique (awkward?) position required.
With the simple and elegant solutions that have been developed around non-setback posts, it would seem to me that it is a preferable way to go. If fitting is consistent with the new position, isn't it an inherently better design?
What gives?

[Saab2000]

Many bikes just don't look as sorted with non-offsets. A lot of what goes on here is aesthetic, whether anyone wants to admit it or not. But there is often some bike design reason for it too. For me? I can't get back far enough with a non-setback post. I can barely get back far enough with most setback posts. Everyone has their own reason.

[davids]

You need the setback you need. So if you're buying an off-the-peg frame, you should be considering how much setback you need (or don't need) and then buy a post with the appropriate setback.

If you're having a frame built, well then, it's something to discuss with your builder. I prefer the look of a setback post, but leave the other design considerations to the effbuilder. For what it's worth - all my bikes have posts with setback.

[Curt Goodrich]

As far as one design being better than the other, I would say only theoretically. In practice the setback seat post has a solid 50+ years of use to back up it's design. As others have pointed out, use whatever puts you where you want to be. Fit aside, I think the reason that some find the non-setback post ugly is because it deviates from their norm or if they've been riding for more than a few years. Back in the not so long ago there were only set back posts. Personally I don't get too worked up about this sort of thing but do prefer a setback post. But then again this princess isn't very sensitive to setback. I can ride a range of setbacks without any issues.

[Dave]

I get the proper look to the offset, however I love thomson posts, but their offset look is terrible. So I use their straight one. only reason for me. the only custom bikes I have ever had made for me I told them I would be using it. They did the rest.

[solfege]

I get the proper look to the offset, however I love thomson posts, but their offset look is terrible. So I use their straight one. only reason for me. the only custom bikes I have ever had made for me I told them I would be using it. They did the rest.

I'm using a Thomson setback because it's the only decent 26.8 post available for my 9 year old NOS IF frame. It wouldn't have been my first choice aesthetically, but it's grown on me rather a bit.

[caleb]

If fitting is consistent with the new position, isn't it an inherently better design?
What gives?

First, the setback post isn't a problem to be fixed. It doesn't break, so the straight post isn't a more functional design. 0 = 0.

Second, for anyone riding a bike properly who isn't a midget, the fit can't be consistent. Look over these four bikes plucked pretty much at random from the gallery:





Here's a thought experiment: Imagine keeping all the contact points the same, but substituting a straight post for the setback one. The only way to keep the saddle in the same spot is to make the seat tube angle significantly more slack. And if you do that, you either physically run into the rear wheel with the seat tube or significantly compromise tire clearance. As a basic geometry problem the straight post doesn't work.

[DOOFUS]

where Caleb is going

weight distribution is better with a setback post. stock geo as we know it evolved with the premise that the rider was using a setback post. fit is about where the weight balances, not about KOPS....

a custom frame with more setback (or, slacker STA, if you must) to compensate for the straight post is another matter.

[caleb]

a custom frame with more setback (or, slacker STA, if you must) to compensate for the straight post is another matter.

Except you'll end up with either really long chainstays (and front end) or very limited tire clearance, both of which can suck.

[dashDustin]

fit is about where the weight balances, not about KOPS....

I keep going back to this statement.

So how is saddle set back determined? Sounds like it's pretty much "wherever. feels good here."

And since Farrar's bike was brought up, would it kill someone to put the barplug in straight. This picture bugs the hell out of me:
Tyler Farrar's 2011 Garmin-Cervelo team bike - VeloNews

[DOOFUS]

So how is saddle set back determined? Sounds like it's pretty much "wherever. feels good here."

where the power is best and the back is flat and the weight is on the sit bones

there is no formula

[spicoli]

Jackpot! I am getting very afraid with how much I've been agreeing with Doof lately!!! ;-) Cheers dude

where the power is best and the back is flat and the weight is on the sit bones

there is no formula

[Jason Musgrave]

visual

A saddle perched on a straight post is to 'nose heavy' visually--doesn't look balanced on top of the post unless it's shoved all the way back (like all the SpeedVagens).

*edit: imho the thing looks right when the transition from the nose attachment point to post clamping surface (rails of saddle) is bisected by the front of the ST/post--pic added for clarification

[sacha white]

visual

A saddle perched on a straight post is to 'nose heavy' visually--doesn't look balanced on top of the post unless it's shoved all the way back (like all the SpeedVagens).

How to say this tactfully?...

Designing a bike that requires the saddle to be slammed all the way back to get proper saddle setback would be some rookie assed shit, right? I know that knowing a lot is the name of the game on forums, but please don't subject my bikes to these kind blanket statements. I take design seriously and put a lot of time and thoughtful consideration into each bike.

Speedvagens are designed so that the saddle is clamped somewhere in the middle of the rails, not "slammed all the way back". Pushed back a bit from center, maybe, but rarely, and only if the options are considered and the choice is deliberate will the saddle be pushed back all the way. This is as it should be.

To the OP, I like straight posts. They're all business and don't (in my experience) compromise fit, aesthetic, or design.

[jerk]

not rookie assed shit. designed for the seat to be slammed all the way back.

How to say this tactfully?...

Designing a bike that requires the saddle to be slammed all the way back to get proper saddle setback would be some rookie assed shit, right? I know that knowing a lot is the name of the game on forums, but please don't subject my bikes to these kind blanket statements. I take design seriously and put a lot of time and thoughtful consideration into each bike.

Speedvagens are designed so that the saddle is clamped somewhere in the middle of the rails, not "slammed all the way back". Pushed back a bit from center, maybe, but rarely, and only if the options are considered and the choice is deliberate will the saddle be pushed back all the way. This is as it should be.

To the OP, I like straight posts. They're all business and don't (in my experience) compromise fit, aesthetic, or design.

[Sasha]

.

Maybe I'm mistaken, but most of these frames are not custom, yes? That would make these examples a compromise between a limited size run from big companies and oddly shaped pro riders (not oddly shaped for their profession).

If they are custom, maybe all these riders have odd geometries that make it impossible to pull the STA as far as it needs to go. So they have to slam the saddle back.

Did pros slam their saddles all the way back in the mid 90s before carbon molds and marketing made it too expensive for riders to have custom bikes?

It's not a matter of East Coast / West Coast style. Allesandro Ballan does not slam his saddle back because he likes the look. There has to be some physio explanation.

[justinf]

Maybe I'm mistaken, but most of these frames are not custom, yes? That would make these examples a compromise between a limited size run from big companies and oddly shaped pro riders (not oddly shaped for their profession).

If they are custom, maybe all these riders have odd geometries that make it impossible to pull the STA as far as it needs to go. So they have to slam the saddle back.

Did pros slam their saddles all the way back in the mid 90s before carbon molds and marketing made it too expensive for riders to have custom bikes?

It's not a matter of East Coast / West Coast style. Allesandro Ballan does not slam his saddle back because he likes the look. There has to be some physio explanation.

Dude. Those geometries are optimized for professional road racing, not for the amateur mass market and adapted to the pros.

edit: unless they are in fact custom, which if I'm not mistaken that Colnago EP is.

[david]

i find this thread, mostly, interesting.
i've often wondered about this very topic.
this is how i've been sorting it in my head. tell me if i'm mistaken.

there's a spot the rider should be in where he has a good balance of weight between front and rear wheels.
obvioulsy, the rider moves around during a ride so he can vary that to his liking. it's not as if there's one and only one spot.
but there is an ideal starting point.

if a bike is designed to use a non-setback post and that post, coupled with the proper seat tube angle, along with correspondingly appropriate geo choices elsewhere on the frame, puts the rider in that ideal spot, then that design - and post - works.
if the frame is designed with a setback post and all other geo choices are in synch with that and the rider is placed in the ideal position, then that's fine too.

what gets effed up is when a rider puts a non-setback post on a bike to compensate for a bike that doesn't really fit him.
for example, at 5'8" i prefer to have the tip of my slr saddle 4cm behind the center of the bb.
a setback post requires me to have a seat tube angle in the 74.5 degree ballpark in order to have the saddle clamped in the middle of the rails.
i see some bikes in what is supposed to be my size from a top tube measurement that have 73 degree seat angles.
when i look at the way these bikes are often presented by their manufacturers, i see a setback post on them.
only way i could get into my position on such a bike is to use a non-setback post. i would then need a longer stem to get the desired reach.
wouldn't that put my weight more forward than it should be?
isn't that where things go wrong?
so, aesthics aside, is the ssue not the post, but the mis-use of the post?

[962]

Allesandro Ballan does not slam his saddle back because he likes the look. There has to be some physio explanation.

well you could also be back and down with the saddle, versus forward and up.

[sacha white]

not rookie assed shit. designed for the seat to be slammed all the way back.

That's cool and all, but for a bike not to have some room for fore/ aft adjustment designed into it wreaks of rookie mistakes. How do I know? because I was that rookie and I made those mistakes....

Signed,

Capt. Scarlet