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Discussion Starter #1
This is my first shaft driven motorcycle. Lets me pose this question. Is it true or am I feeling funny in that more power is being sent to the shaft than a chain. The raw feel of power is quick and responsive. There no hesitation what so ever. My feeling is, the choice to get a shaft was the absolute right one.
Thanks
Ray
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Well, actually, I think that the power the engine deliveries to the transport mechanism is the same regardless of the method used. But inherent in all transport systems is power absorption, reducing the power available to drive the rear wheel.

Of the three methods commonly used, chain, belt, and shaft, the one that absorbs the least energy is the chain, followed by belt and then shaft. [Note: the discussion assumes that the engine has a transverse crankshaft as certain engine layouts such as the BMW opposed twins, Honda's opposed fours and sixes, and Moto Guzzi V-twins are natural candidates for shaft drive.]

If you consider what it takes to transmit the power via a shaft drive, the power is required to be rerouted twice through 90 degree turns such as in the differential of a car. Each one of these assemblies has mass that must be accelerated, and has frictional losses associated with it. This take power which is then not available to accelerate the wheel. There is also a slight handling issue with suspension jacking under power. Is any of this real significant in the cruiser application; not really.

The beauty of shaft drive is near zero maintenance which is really significant.

Chain and belt drive are close in efficiency, with the edge going to chain. The edge is probably due in large part to the lower mass of the chains sprockets over the belts wheels.

The down side for the chain is the frequent, actually incredibly frequent, maintenance cycle measured in probably 500 mile intervals and each clean, lube, tension, etc is a pain.

However you look at it, on a cruiser where getting the absolute max performance is not an issue, I would choose shaft or belt over chain every time and the actual power loss isn't much for shaft over belt or chain.

Why belt vs shaft; it is much more costly to build a shaft drive system as opposed to a belt system.

Which is the best system; for a cruiser, I think shaft is the best (and I have belt on my 900). So in summation, I think you made the best choice.

But, are you not sorry you asked now? :)
 

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Discussion Starter #3
Shiloh; That was very well put. You almost lost me for a minute with talk of mass, accelerated, frictional losses. The more I read the more technical it became. Thanks to my fifth grade school level edumacation. I was able to follow you with a little help from my friends...ha ha ha.
Thank you
Ray
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