Originally Posted by 2door
I have to wonder if your opinions/assumptions are based on experience. I've had the opportunity to ride a number of rear rack mount bikes, both with the engine centered over the rear wheel and mounted side saddle, off to the left. I'm a lightweight, so if the weight or balance were factors I would have surely felt it. I've never experienced any instability or balance problems with either application.
I completely agree. I have a rear mount GEBE setup. Before I completed my build I had some worries about balance and high center of gravity, but after riding my new motor bike, I found they are not an issue at all. The bike rides beautifully with no feeling of being unbalanced or top-heavy.