Originally Posted by
Peterpan1
Mainly though, MTBs pioneered the idea that a bike could show a lot of seat tube, and once that became accepted as a strong design there really aren't many advantages to a level top tube.
I think the great disadvantage to a level top tube is standover height, which I agree is a problem if you have a long torso or are going off road.
However, a compact/sloping frame in small sizes does have one disadvantage - there is less room in the main triangle, eg. a full-size water bottle won't fit on the seat-tube bottle cage, there isn't room to put a pump below the top tube, no room for a wedge pack.