If your LBS doesn't do many of them (if any), you may have to spend some cash-ola on a third-party fitting. A lot of shops can fit a rider to a bike, but a really good, certified fitter can fit an existing bike to the rider. I speak from experience on this - I bought a used roadie from someone on Craigslist a few years ago using a basic calculation based on my height which worked out to me being around a 54 cm, but it didn't feel quite right no matter how much I played around with the different adjustments, I invested in a good fitting using a shop recommended by a former neighbor who races and it was like night and day. Well worth the investment.