hey that's me YA'LL talking about
it's important to know that using thun with CA 3 allows you to fine tune your performance, for example you enter the factor the motor input in proportions to your pedaling ( by 1, 1.5 2 etc..) you can also set minimum HUMAN watts required to actually get the motor running, so it could either from 100 or from 50, i believe this would ensure you won't get any surprise jumps from the motor, (it also depends on the controller you have, getting a balacned curve of throttle to amps).
however even though i do want to keep the option for pedal assist i wouldn't want it hamper any real speed gains i might get.
i allready know about sheldon's gear calculator, that's how i got the impression that using the standard reduction of 33:1 would get a max theoretical speed of abou 50 kph, which would proably mean less in real life at least 45 if not 40 kph. doing 38 kph is possible today with my mac motor with better battery life. so in order to increase that speed i would need to do at LEAST one of the following
1. decrease the alfine sprocket from 20T to 18T - but that means dealing with snap ring of doom, and i'd rather avoid that. plus it doesn't increase speed by much
2. increase the front chain ring sprocket to 50T (maximum 104 bcd i could find) - that would increase the theoretical speed to 64 kph, while using the standard kit's reduction, but would over step shimano's recommendations of 1.9 ratio between sprocket and front chainring
3. decrease the reduction ratio of drive. if i order the most extreme combo of 64/18 sprockets on top of 80/12, i could have a 181,150,97 rpm settings i could play around to get speed vs power settings
4. move to 72 voltage pack - but i just started using paul's pack and i REALLY don't want to spend more.
the current performance i'm getting is really good thrust, i can reach 50 kph in less then 10 seconds. but the usage is around 36wh/km. and i understand that's less then what's acceptable.