Here's a pic of a Thomson setback on my mountain bike. I've always had good luck with Thomsons on my mountain bikes, and I needed some setback to get the right fit on this particular bike, so I went with the Thomson setback. Although it looks kind of dramatic with the bent shape, it actually has about the least amount of setback of any setback seatpost you'll find, just 16mm. Most setback seatposts have 20-25mm of setback, and of course most of them get their setback from their shape at the top, not well down the post like the Thomson.