I currently just finished my first century bike ride on a 12 year-old schwinn crisscross. I got hooked and want to try another century, but not on my old bike. I am currently looking into purchashing a hybrid bike; road bikes hurt my back! I've narrowed my search down to two bikes: the Jamis Coda Comp and the Sirrus Comp by Specialized. The geometry of each bike is similar, however, the components aren't. Does anyone have any riding experience with either of these bikes? If not, could you tell me if a rear derailleur made of Shimano Deore XT is better than Shimano 105? Your help is appreciated!