Average sized rider can't find the right fit

[indysteel]

I would try a longer stem on the 51. I'm long waisted and 5'4. I have one bike that's a 50 and another that's 49, so a 51 for your height doesn't strike me as "wrong." You can lengthen your reach, too, with different bars.In the end, it's easier to make a bike bigger than it is to make it smaller.