No pain so far, except a little at first in the neck & lower back. After riding a bit more and reading about correct form, it's no longer a problem. It honestly doesn't feel too small. Also, it's right in the middle of their sizes, which I think are 46, 49, 51, 53, 55, 57, and 60. I'm only about 5'10", so if it was too small I think it might just be one size small. The specs say the stem is 100 mm but 120 mm for the 55, so perhaps a 120 would work better if I start to feel cramped. I'll ride it more and see how I feel.