Originally Posted by
Duragrouch
Wow, 2.5, that's a really big overdrive in one step, at least for a planetary gear, which it's probably not, I can picture in my mind how they would do that. I could see how that would add a lot of whirr noise, and hurt efficiency, I'm sure the driver for the newer simpler system.
no it was pretty efficient. bosch is known for them sot range for the least amount of battery. but that small chainring was noise and wore out faster. Plus the bearing on that side had to be more complex. but thats to the wire sound the tandem as 12,0000 miles on it and the sound is new.