Haraka...
The chain is the worse feature of the Wright machine, but the slow motion of the propeller makes up for it at least partially.
If you can get the power from a propeller making 500 revolutions per minute you will get about 75 per cent efficiency out of your machine. If the propeller makes 1,200 revolutions per minute you can only get about 50 per cent efficiency. That is what gives the Wright machine an advantage. With its two propellers it gets power without making as many revolutions as where a single propeller is used, and I think the advantage in efficiency more than makes up for what it loses by having that horrid looking chain"
Interesting quote from Sopwith !
Of course the other real advantage of the orrible looking chain drive is that it was relatively easy to change sprocket sizes etc and therefore be able to fine tune the prop RPM if required !
rgds LR