Joined: Jun 2009
Posts: 2,242
Likes: 1,659
From: PacNW
Bikes: Dinucci Allez 2.0, Richard Sachs, Alex Singer, Serotta, Masi GC, Raleigh Pro Mk.1, Hetchins, etc
Get somebody to take your pic as you ride by, if possible in the same position on the bars etc.
Compare the pics to identify any possible biomechanical issues.
My own limited experience is that lower back problems are best resolved by sliding the seat forward.
Get good measurements and take notes as you make (small) changes
Mark Petry
Bainbridge Island, WA USA