My brother is new to riding and is uncomfortable on his bike when he is in the drops. He says "Riding on the drops is not comfortable. When I do, I feel like the seat is too far forward. (emphasis mine) I will get down on the drops when I go down this huge hill near my house. I eventually will come up off the seat and move further back. It could just be flexibility. My lower back hurts when I stay low too long. Or that I am fat and my thighs are hitting my gut."

The "seat is too far forward" makes me think that maybe the bike is too big and he gets too stretched out putting more weight on the front of the saddle? Does this sound right?

I asked him to send me a pic of him on the bike in the drops so I can have a better idea.