Why Cutout Dimensions Matter
We’ve been asked a few times, “A cutout reduces the area of contact with the saddle, that means more pressure on the rest of the body. Isn’t that a bad thing?”
We gave some thought to that question and we believe that if the increased pressure is on load-bearing parts of the body and not on the perineum, then it’s fine. Put in a different way: if the cutout is wide and long enough to prevent any pressure from being placed on our perineum, then it is a good thing. We elaborate very briefly on our answer below.
The Basic Zones
We divide the body surface in contact with a saddle into two general zones: load-bearing (around sitbones and rami), and soft-tissue (perineum).

The Correct Cutout
The saddle with the right cutout is one where the perineum (that will otherwise be in contact with the saddle) fits entirely within the cutout:

In this scenario, body weight is borne entirely by the sitbones, which is fine.
Wrong Cutouts
On the other hand, a cutout that is too narrow results in the sides of the perineum experiencing pinching/higher pressure (shown in red):

We could have a debate about whether such a scenario is better or worse than, say, a saddle without a cutout, but it is safe to say that neither is as good as one with a sufficiently large cutout.
Found this (really, really, really short) article useful? Check out other cycling-related stuff at meld3d.com/blog.