Singlespeed & Fixed Gear - Seat post offset

when measuring the offset of a seat post, what are the guidelines? From where to where do you measure? Thanks

Good luck on this one.

Most seatposts are 25mm offset. The Thomson is 16mm offset. It refers to the offset of the center of the clamp relative to the center of the tube.

Good luck on this one.

it's not THAT hard to figure out...

Good luck on this one.

You could guess the answer and be right.

it's not THAT hard to figure out...

Ok, then lets hear it. Enlighten us?

The answer is right here. Four posts above this one.

But like I said, anyone with half of a brain could figure it out by guessing.

If your going to try to live up to your name crushkilldstroy then maybe you should first do your home work and know a little about current frame & old component design before trying make full brain/smart comments.


The question was how to measure Setback. Measure centerline of seapost tubing, from that point horizontally measure to the center between the forward & rear saddle mounting sections.

It sounds like the question was to try find out the true seat post angle with the seatpost incorporated.

There has been no real standard in todays frame design. A lot of new seat posts are now zero setback because this gives a more true end result for frame designers reaching there ergonomic & balance goals.

By the way, the 16mm setback for the Thomson seatpost is not for their standard seat post which is actually is zero setback. Old campy is 20mm, newer ones measures 25-28mm. Nitto states 25.4 but actual measurement is around 19mm, Salsa is 16mm, Ritchey 20mm, Easton is also different, Kalloy measures 28+mm. 25mm was an unofficial standard but the manufacturers don't follow it, so there is no real standard and varies widely if you measure the effects on the seat post/saddle angle. Setback helps dampen the road.

Most frame makers have designed there bikes with zero setback in mind. If you look at custom frame makers, they will make a zero setback seatost for there customers.

If your going to try to live up to your name crushkilldstroy then maybe you should first do your home work and know a little about current frame & old component design before trying make full brain/smart comments.


The question was how to measure Setback. Measure centerline of seapost tubing, from that point horizontally measure to the center between the forward & rear saddle mounting sections.

It sounds like the question was to try find out the true seat post angle with the seatpost incorporated.

There has been no real standard in todays frame design. A lot of new seat posts are now zero setback because this gives a more true end result for frame designers reaching there ergonomic & balance goals.

By the way, the 16mm setback for the Thomson seatpost is not for their standard seat post which is actually is zero setback. Old campy is 20mm, newer ones measures 25-28mm. Nitto states 25.4 but actual measurement is around 19mm, Salsa is 16mm, Ritchey 20mm, Easton is also different, Kalloy measures 28+mm. 25mm was an unofficial standard but the manufacturers don't follow it, so there is no real standard and varies widely if you measure the effects on the seat post/saddle angle. Setback helps dampen the road.

Most frame makers have designed there bikes with zero setback in mind. If you look at custom frame makers, they will make a zero setback seatost for there customers.

You just reiterated what MIN said, and then typed out a bunch of other stuff that the OP didn't ask for.

Like I said, it's a simple question with a simple answer. The question was "How do you measure the offset of a seatpost?" And the answer is "The distance between the center of the clamp and the center of the post itself."

And of course a zero setback Thomson has zero setback. A setback Thomson has 16mm of setback.

And if actually you knew all of that information without plagiarizing it off of google, then why didn't you post it in the first place?