hi all, I could be wrong but I seem to remember something called maybe Saxton or Saxon that had a semi split seatube.
From memory the Puch and Rigi are similar in the fact they both have 2 seperate seatubes, as opposed to others that I have seen, as well as the one that Martin is talking about from eBay, that seem to be similar to a set of forks with straight fork blades, a good design in itself, not that my Rigi has given me any problems.
This design seems to have appeared in recent OT frames as a seatstay setup, so when it comes to frame design, nothing seems to be new, maybe just the methods of construction and the materials used.
I wonder when we will see the true split seatube design next in a racing bicycle......regards wayne davidson Invers NZ......