This article is from the Bicycles FAQ, by Mike Iglesias with numerous contributions by others.
From: Jobst Brandt <email@example.com>
Date: Fri, 10 Dec 1999 10:26:21 PST
> I was wondering if someone could direct me to a bike seat that is
> soft. I have a Specialized-brand bike and the seat is hard. What
> is the softest seat available?
You may already have heard something like this but I think it bears
repeating. Bicycle seats are much harder and narrower than you might
expect because they are designed to bear on a small area, primarily
the protuberances of the pelvic bone that you can feel as solid bumps
if you feel under your buttocks as you sit in a chair.
If you sit on a larger area, for instance on a soft cushion, you will
be sitting on the muscles that propel the bicycle. Although this may
be comfortable sitting still, pedaling, it causes a "charley horse" in
these muscles for lack of adequate blood circulation. You will want
to avoid such soft saddles if you plan to ride more than a few hundred
yards because riding will become painful. A better course is to ride
a conventional firm saddle, repeatedly, until your seating is no
longer sensitive. All bicyclists who ride substantial distances
achieve this condition, albeit with various saddles, none of which
have the broad deep cushion often sought by newcomers.
Even an experienced rider who is laid up or otherwise cannot ride for
more than a month, experiences much the same discomfort you do when he
returns to riding the saddle that he previously never gave a thought.
The big cushioned saddles are made for people who don't ride bicycles.
That is why there are so few of them available, and they are generally
not found in bicycle shops where the regulars shop.