The problem about weight limits is that a true weight limit is a dynamic figure. In other words, the same bike may be able to carry quite safely:

– a 400-lb cyclist who pedals smoothly on smooth roads;
– a 300-lb cyclist who pedals smoothly and carefully on pothole-ridden roads;
– a 150-lb cyclist who mashes, jumps curbs and rides fast downhills on streets that look like a mine field.

Now what figure(s) do you give out? And if you give more than one, how do you describe the other parameters?