Chain attatched to centre sprocket?

[Matt Barrack]

Ok so on my bike, the chain is connected from the gear on the engine, to the sprocket on the rear wheel. Recently, I've seen pictures of motorized bikes with the chain attached from the engine sprocket to the centre sprocket. Would this gearing result in better performance? I'm aware it looks like there would be more work.

 

[crassius]

a lot more work, a lot more money, and its own set of problems - with a good set of gears on back wheel, it can be useful tho