Originally Posted by Road Fan

Adjusting an SA is kind of intricate. I have a bunch of SA and have not noticed that problem, but I adjust them carefully. My guess is yours needs adjustment and setup. You also should progressively adjust the tension screw to maintain 6mm max spacing across the slot - just a little bit at a time. They discuss it on their site.

Sagging/hammock: it is designed to work as a double hammock, and needs a limited amount of sag. As such, it's more supple than say, a B17. It's possible to make it feel stiffer if you tighten it rather past the 6 mm width. SA does not recommend this. I've never noticed lateral motion, unless perhaps you have the saddle raised sitting up too high and you're getting a lot of hip rocking. Seems like somebody loves every saddle, and somebody hates every saddle.

For the list of recommendations I would add, look at the Specialized Gel Toupe in your width, and at other Specialized models. I think they're pretty goodl