A little more expensive than I'd like, but for a sore back, the 2" setback on this is just the thing: http://www.rivbike.com/products/show/nitto-wayback-seat-post-272-x-250mm/11-048
If you don't need that much, say only an inch, these are nice too:
http://www.rivbike.com/products/show/nitto-crystal-fellow-seatpost-272-x-250/11-031
http://www.rivbike.com/products/show/nitto-s-83-seatpost/11-078
If you don't need that much, say only an inch, these are nice too:
http://www.rivbike.com/products/show/nitto-crystal-fellow-seatpost-272-x-250/11-031
http://www.rivbike.com/products/show/nitto-s-83-seatpost/11-078
