wheel size on one cams

[split-fire]

What's the reason for useing large idler wheels vs. smaller ones. I've allways thought it was to push the string the same distance from the axle as set buy the cam however after looking at several one cam bows this seems untrue. I'm looking at getting a new bow for 2005 and this is one of the major isues in my purchase. Are larger wheels smoother or should i not base my purchase on this issue.

[Bigpapascout]

same principle as how a larger wheel takes less revolutions to turn the same distance as a smaller wheel.
it also has a lot to do with nock travel, a shorter wheel will produce more eratic nock travel opposed to a wheel that is the closer to the diamiter as the eccentric this also makes a more level nock travel due to the idler and eccentric having the same tiller measurment at full draw and let down.

However there is such thing as having too large of a idler wheel also.
a perfect idler wheel diamiter will be the same measurment as the narrowest part of the eccentric which is usually 3.5" or there abouts.