Single or double treadle?

[quirky]

What are the advantages of a double treadle wheel?
Is there a major difference from a single?

[schrodinger]

This quote is what I found on Woodland Woolworks about the double/single treadle difference:
"A double treadle wheel balances the treadling work on both feet and legs and may therefore be more comfortable and ease strain on the hips and lower back, especially over long periods of spinning.

With smaller wheel diameters, especially in upright wheel designs, lower wheel momentum may make treadling feel jerky and make it difficult to maintain consistent rotation especially at slow spinning speeds. Double treadle mechanisms overcome this by providing two "power strokes" per wheel revolution. Starting the wheel is also easier."

Hope that helps a little

[Arugula]

Also, a spinner friend told me it is really easy to change the direction the wheel is rotating with double treadles. With a single treadle you have to guide it which way to start going and you can't switch directions without using your hands. He only has double treadles so that is all I have any experience with (don't have one of my own) but I agree that it is easy to stop and change directions with a double treadle.