Originally Posted by slowandsteady
I don't get it. Unless you doing the ironman, the bike portion isn't that long. Should comfort really matter that much in a race of less than an hour. In training, unless you are doing blocks, you can still wear bike shorts.
My chamois are barely padded at all and my saddle, a brooks, has zero padding.
Errrr. . . . a tri saddle might be 50 grams heavier than an average road saddle due to the extra "padding." I don't think that's worth giving up on comfort. Get on a tri/tt bike with really low handlebars sometime - it's nowhere near the same position as on a road bike, padding (or at least a comfort-oriented shape) is more critical. Your entire body is rotated forwards, so you really have no chance of putting weight on your "sit bones" as you would when riding a road bike. Like it or not, your body weight is pretty much all going to be concentrated directly on your genitals. Getting into this position on a regular road saddle or the wrong tri saddle, even with padded shorts, can be totally, unnervingly, uncomfortable in 5 minutes, let alone even a 10 or 15 mile sprint triathlon distance. Even if you were "tough" enough to make it through the bike portion with an uncomfortable saddle, I don't think I'd want to continue on to the run portion with a sore crotch.
To the OP - besides padding on the nose, the overall shape of tri saddles is typically very different. They're usually much wider up front (to help distribute weight when you're out on the nose) and usually less wide out back in the wings (since you're almost never on the back of the saddle anyways.) To sum up, a "regular" road bike saddle is generally designed for you to put pressure on the wider wings near the back of the saddle, with your sit bones. A tri saddle is designed to make the best of a position that's naturally much less comfortable - putting weight on the nose of the saddle through a spot farther forward on your anatomy.
That said, they can be comfy if set up correctly. I have a Selle San Marco Azoto Tri Race Gel saddle, and my position lets me get aero while staying far enough back on the saddle to be pretty comfortable. (This saddle is 280g, FWIW.) If you're a true weight weenie, Selle also makes a 190g saddle, the Selle San Marco Aspide Black Angel. I've never ridden one, but my 290g saddle hasn't ever prevented me from doing well and having fun.