Suzuki variable valve timing. 1992

I remember when Suzuki introduced variable valve timing to the motorcycling world on the 1992 Bandit 400 and trying to figure out a mechanism that would allow that. 

So if you're an engine guy, give a thought to how you might do it- before looking at the image...  

This would add quite a bit of reciprocating weight in the valve train but it didn't seem to be an issue, the engine revved to 12,000 rpm.