
In an effort to uncover any dangerous instability, I stood up and leaned way forward, I scooted way back onto the passenger seat, I rolled on and off the throttle, hung off the left and right, braked and accelerated hard, and basically tried every trick I could to provoke the bike into misbehaving. Nothing evil happened at all -- the vibration didn't amplify into anything. It's a slight vibration, not anything that rattles your teeth or threatens to yank the bars out of your hands.
The rear suspension is squeaky, but nothing's loose. There will be some greasing of pivots and such in the near future.
I hadn't ridden a GR650 before. Pretty nifty engine -- basically, a 650 parallel twin that doesn't vibrate. The bike itself feels like a smaller GS -- it's on the scale of a 550 or 650. The engine architecture is different than the 400/450/500 2-valve twins.
As we suspected, pretty much everything on the bike is identical to a GS of the era -- Suzuki doesn't re-engineer parts unless it has to.

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