Originally Posted by
Juha
One thing to consider is, there'll be some internal friction with the Schlumpf. You'll have to decide for yourself whether you're willing to lose some drivetrain efficiency to get the extra gears. I don't know if anyone has attempted to quantify how much the loss in efficiency would be.
--J
As Jur pointed out, in the two most likely gears, the Schlumpf would be engaged in one of them. However, solely from memory since I can't recall the source, I remember something like a 3% loss so it doesn't matter much.