Top Tube Angle

Hello All :

My first post on this forum -

Why do many road bikes now have a sloping top tubes rather than ones that are parallel to the ground ? What are the benefits of this relatively new geometry ?

In addition, I’ve noticed that within the same model of a road bike, the smaller sized frame, say a 51cm, has a top tube that slopes at a larger angle than say a 54cm or 57cm, etc. Why is the slope angle within that model not kept the same ?

Wish to get a better understanding.

Thanks in advance.


Jai

Comments

  • webboo
    webboo Posts: 6,087
    It’s hardly new having been around for at least twenty years. Frames are lighter and more rigid.
  • I have a level top tube because it looks better
  • webboo said:

    It’s hardly new having been around for at least twenty years. Frames are lighter and more rigid.

    I am working on getting back to cycling after decades - I had noticed the change in the top tube angle but did not know the reason.

    Thanks !
  • bondurant said:

    I have a level top tube because it looks better


    I perhaps am old school as I too visually prefer the parallel top tube and am working on appreciating the angled tubes.

    Thanks !
  • pblakeney
    pblakeney Posts: 27,065
    webboo said:

    It’s hardly new having been around for at least twenty years. Frames are lighter and more rigid.

    Until you add on a saddle and longer seatpost.
    The above may be fact, or fiction, I may be serious, I may be jesting.
    I am not sure. You have no chance.
    Veronese68 wrote:
    PB is the most sensible person on here.