Once again Soren, the Speed Twin WAS the "Bonneville" of its day. It just took a few years for the frame technology(i.e. the swing-arm rear suspension, primarily) to evolve.
And, I think the ONLY reason you might think that there's some "similarity" between the Speed Twin and the Speedmaster would be that they're both Vertical-Twin engined motorcycles, AND maybe because the slopping down of the frame rails aft of the gas tank on both bikes. BUT remember the ONLY reason for the Speed Twin to have that would be because of its rigid frame which was the norm on machines of that vintage and years before the swing-arm rear frame would become standard. And the ONLY reason the BAs and Speedies have this slopping down frame is to make the seat lower...which all "good Cruisers" should evidently feature in order for its operator to "look cool" while riding it!!!
