Last summer I hit 44 mph on my old loaded touring bike. With a 48 x 13 top gear, I really couldn't push beyond that. This was down a steep hill, of course, descending into the Deer River valley in north western Massachusetts. A few weeks later, I reached 42 on a hill only a mile or two from the house I was living in at the time. On flat ground, I can sprint to about 31.5 mph. That might have changed - I haven't been riding a whole lot lately and I have a couple different bicycles now. Problem is, it can be hard to find flat ground in these parts!