You can see that the rake is different.
The Speed Twin had taller wheels. Ours have the typical cruiser stance of taller front and short rear.
The frame geometry looks similar, of course the cruiser style is based on the old hardtail shape, and the parallel twin engines are proportioned alike adding to the idea of consistence. I'll bet if you did the same with some HDs and Indians of that era, you'd get comparable results.
