Originally Posted by
thenomad
smaller triangles are stronger than larger triangles
+1
Notice how mtb. bikes have smaller triangles and bmx bikes have much smaller triangles.
And today's oversized carbon seatposts are incredibly stiff as are the frames. Oversized bottom brackets, larger headtubes and customized shaping of each "tube" in the frame makes a modern carbon fiber frame stiffer than a traditional steel frame.