Originally Posted by JAB
Don't want to start a who, when, where issue, but I think chambers go back further than the 60's. Look up some the crazy engineering from DKW road racing and I believe you'll see chambers, 2 strokes with superchargers, all sorts of crazy stuff.
I was thinking it was MZ. Didn't Walter Kaaden develop them for MZ's roadracers? Then Ernst Degner defected to the west and took the engineering secrets to Suzuki. Who said the Japanese didn't copy anyone else?
Regarding old Huskies, my WR250 didn't really like turning either, nor were its brakes much to write home about, but what a sweet motor! An easy bike to ride all day.
As for all the different displacements, when two strokes first were built over 250cc, the metallurgy and general engineering were a little marginal for dealing with the increased heat. As the factories learned from their experiences we saw the growth from 360s to larger engines. There was lots of experimenting. Many folks found the 250's easier to ride, as an earlier poster stated.
I would argue that water cooling was a big break through. It wasn't long after radiators appeared on 125's that an aircooled bike become too slow. Water cooling allowed engines to be built to generate more power because liquid did a better job of letting the engine effectively shed the heat that comes with more power. Tighter tolerances can be used by thermal expansion of dissimilar materials happens in a more controlled fashion with liquid cooling than air cooling. I still prefer the look of an aircooled motor, but power is power.