Okay, I was having my after dinner coffee and looking at my bike and especially that butt ugly chain tensioner. The most unattractive part of the machine and mentally designing a better looking one when I ran across my old front and rear derailers in a srap parts box. I started playing with the rear one and thinking how I could use it as a spring loaded tensioner when I came up with a thought. Could I stack two sprockets, spaced apart, on the rear wheel, attach the derailer with either a wheel or a sprocket and shift gears by derailing the drive chain over to the side just the width of the chain or enough to engage the extra rear sprocket? Has anyone here ever tried it? In my mind I can see it working with a little modification to the left seatstay to clear the chain...but it should work. Chain alignment is critical but moving it a chain width that far back shouldn't compromise the chain's running on the engine sprocket. These chains have enough flex to allow the slight misalignment necessary. Any comments, suggestions?