layback seat post- why?

samsbike
samsbike Posts: 942
edited January 2019 in Road beginners
I have seen some bikes with layback seatposts? Why do they have then, doesn't it put the leg in the wrong position with respect to the crank?

Thanks

Comments

  • flasher
    flasher Posts: 1,734
    Most road bikes come with layback seatpost, in fact I can't think of any that come with 0 setback! So I'd say that having layback puts most people in the correct position.
  • desweller
    desweller Posts: 5,175
    Layback and setback are not exactly the same AFAIK; the former incorporates a bend in the seatpin, whereas the latter refers to the offset of the clamp from the (straight) seatpin axis.
    - - - - - - - - - -
    On Strava.{/url}
  • napoleond
    napoleond Posts: 5,992
    layback seatposts do the same thing as setback seatposts. In a slightly different way.

    I have to have setback to get the correct position on my bike, as do most people.
    Insta: ATEnduranceCoaching
    ABCC Cycling Coach
  • flasher
    flasher Posts: 1,734
    DesWeller wrote:
    Layback and setback are not exactly the same AFAIK; the former incorporates a bend in the seatpin, whereas the latter refers to the offset of the clamp from the (straight) seatpin axis.

    All much the same thing either offset or straight, FWIW Thomson refer to their 'bent' seatpost as setback!
  • MichaelW
    MichaelW Posts: 2,164
    The amount of layback any particular individual needs depends on the length of the crank, the length of the leg (or more specifically the femur) of the particular individual.
    In the olden days, seatposts came in one style only with no choice of layback. Custom builders made a living from a building bikes with different seatpost angles to suit particular individuals.
  • samsbike
    samsbike Posts: 942
    cheers all. I think I am confused between layback and set back.

    It was the thomson ones and some are straight while others have an angle and I could not understand why
  • marcusjb
    marcusjb Posts: 2,412
    They are very useful if your saddle has a short rail section.

    Brooks, in particular, require a setback post for most frames.
    Stuff about riding a bike a long way
  • rayms
    rayms Posts: 1
    Why do mountain bikes have the lay back instead of the setback clamp of the road bikes?
  • the_cyclist_of_catan
    the_cyclist_of_catan Posts: 354
    Necessary because of the changes in bike cram geometry over the last few decades. The "compact" frame with a sloping top tube means that seatpost angles are now different - and we ride bikes with more seatpost exposed - than those of classic steel frames of the 90s and earlier. Which in turn necessitates a layback seatpost to put the saddle in the right place for most of us.
    They use their cars as shopping baskets; they use their cars as overcoats.

Categories